I think I'm using the correct terminology here, forgive me if I'm not....

I have S-plan - hot water comes out the boiler, through the pump, then divides into three (it was two, but I modified it!) to go through three independent valves. One goes to the heat exchanger in the hot water tank. Another goes to the radiators in the house, the other goes to radiators in the garage (I converted it to a parrot aviary, and electric heating is expensive!).

My question is, what is the point of C-plan - where you don't have a choice, you have to heat the water when you heat the house (or is it the other way round?). My parents boiler is set up so they have to heat the water when they heat the house. What if the house is too cold, but you aren't planning on taking a bath that day? I know the heat from the tank will eventually seep out into the house, or get used later as hot water, but it seems daft to throw heat into something you don't want right now.

--
http://petersparrots.com
http://petersphotos.com

The 2 most common elements in the universe are hydrogen and stupidity.

On Nov 30, 9:12*am, "Lieutenant Scott" wrote:
My question is, what is the point of C-plan - where you don't have a choice, you have to heat the water when you heat the house (or is
it the other way round?). *My parents boiler is set up so they have to heat the water when they heat the house. *What if the house is too
cold, but you aren't planning on taking a bath that day? *I know the heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into something you don't want right now.

I believe that C-plan is mainly (only?) used for pumped heating with
gravity hot water systems.

HTH,
BraileTrail

Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler. Pumps
generally last a lot longer (or at least they used to) than motorised valves
where problems with either the motors or the switches are relatively common.

In these days of higher fuel costs and possibly higher HW consumption, fully
pumped systems with motorised valves make more sense for 99% of the
population who want as stored HW system but the simplicity and reliability
of the old systems may be valued more by folk who don't use a lot of HW.

Tim

On Wed, 30 Nov 2011 11:32:38 -0000, Tim Downie wrote:

Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler. Pumps
generally last a lot longer (or at least they used to) than motorised valves
where problems with either the motors or the switches are relatively common.

In these days of higher fuel costs and possibly higher HW consumption, fully
pumped systems with motorised valves make more sense for 99% of the
population who want as stored HW system but the simplicity and reliability
of the old systems may be valued more by folk who don't use a lot of HW.

Oh I see. Thanks. I've never had a problem with the two motorized valves in the 10 years I've been here. And a replacement valve is only £20 anyway (that's what I paid for the third one I just added - in fact even less if you just replace the motor/switch unit).

--
http://petersparrots.com
http://petersphotos.com

Why isn;t the apostrophe next to the L? Who ever uses the semicolon???

Lieutenant Scott wrote:
On Wed, 30 Nov 2011 11:32:38 -0000, Tim Downie
wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part outside
the boiler. Pumps generally last a lot longer (or at least they
used to) than motorised valves where problems with either the motors
or the switches are relatively common. In these days of higher fuel costs
and possibly higher HW
consumption, fully pumped systems with motorised valves make more
sense for 99% of the population who want as stored HW system but the
simplicity and reliability of the old systems may be valued more by
folk who don't use a lot of HW.

Oh I see. Thanks. I've never had a problem with the two motorized
valves in the 10 years I've been here. And a replacement valve is
only £20 anyway (that's what I paid for the third one I just added -
in fact even less if you just replace the motor/switch unit).

As you say, motorised valves aren't really a big issue for DIYers but they
could be a major cause of expense and inconvenience to non-DIYers. You only
need to read a few "My combis stopped working!" threads to realise sometimes
reliabilty is more important that maximum efficiency for some folk.

Tim

"Tim Downie" wrote in message
...
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler.
Pumps generally last a lot longer (or at least they used to) than
motorised valves where problems with either the motors or the switches are
relatively common.

snip

two houses ago I was on 'C' plan and it worked very well.
I had a Parkray anthracite bean boiler for heating the living room, hot
water and radiators during the colder months.
I also had a Raeburn cooker with a back boiler which we used for heating the
kitchen and for cooking for most of the year.
This also gave us "free" hot water.

Now with older style solid fuel back boilers you don't want any valves to
restrict the circulation of the hot water from the back boiler to the hot
water tank or you could build up a head of steam - a couple of times we
forgot to shut the damper on the raeburn and managed to boil up the hot
water tank in the middle of the night.

The Parkray was fine, because it had a thermostatic damper.

I can't remember now if the two gravity systems were linked or if we had two
coils in the tank.
I suspect the two boilers were linked up near the tank.

So perhaps no point on modern systems (apart from simplicity) but with less
sophisticated heat sources the 'C' plan can work well.

Thinking on this, how are solid fuel stoves with back boilers linked into
heating systems these days?
Gravity feed to a heat store?

Cheers

Dave R
--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

(\__/)
(='.'=)
(")_(")

On 30/11/2011 09:12, Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm not....

I have S-plan - hot water comes out the boiler, through the pump, then
divides into three (it was two, but I modified it!) to go through three

That makes it S-Plus Plan now then:

http://wiki.diyfaq.org.uk/index.php?...s:_S_Plus-plan

independent valves. One goes to the heat exchanger in the hot water
tank. Another goes to the radiators in the house, the other goes to
radiators in the garage (I converted it to a parrot aviary, and electric
heating is expensive!).

My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it the

Well, C-plan if done completely:

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan

Does have a choice in the sense that if the water cylinder is hot enough
the zone valve that permits gravity circulation does not open.

However older installs probably don't even have the zone valve on the
cylinder. (some other temperature sensitive / thermostatic valves were
also around at one point to inhibit flow to a hot cylinder)

other way round?). My parents boiler is set up so they have to heat the
water when they heat the house. What if the house is too cold, but you
aren't planning on taking a bath that day? I know the heat from the tank
will eventually seep out into the house, or get used later as hot water,
but it seems daft to throw heat into something you don't want right now.

Indeed. One of the reasons such systems are deprecated. However, if you
change it to be a genuine C plan setup as per the diagram above and the
wiring:

http://wiki.diyfaq.org.uk/images/0/0d/S-Plan-Wiring.gif

The you can use the programmer to not have the water heated when running
the heating. It does mean there needs to be a two port valve in the
water heating loop though.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 30/11/2011 14:14, David WE Roberts wrote:

Thinking on this, how are solid fuel stoves with back boilers linked
into heating systems these days?
Gravity feed to a heat store?


Yup can be... sometimes a separate coil HE in the cylinder...


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 30 Nov 2011 13:06:12 -0000, Tim Downie wrote:

Lieutenant Scott wrote:
On Wed, 30 Nov 2011 11:32:38 -0000, Tim Downie
wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part outside
the boiler. Pumps generally last a lot longer (or at least they
used to) than motorised valves where problems with either the motors
or the switches are relatively common. In these days of higher fuel costs
and possibly higher HW
consumption, fully pumped systems with motorised valves make more
sense for 99% of the population who want as stored HW system but the
simplicity and reliability of the old systems may be valued more by
folk who don't use a lot of HW.

Oh I see. Thanks. I've never had a problem with the two motorized
valves in the 10 years I've been here. And a replacement valve is
only £20 anyway (that's what I paid for the third one I just added -
in fact even less if you just replace the motor/switch unit).

As you say, motorised valves aren't really a big issue for DIYers but they
could be a major cause of expense and inconvenience to non-DIYers. You only
need to read a few "My combis stopped working!" threads to realise sometimes
reliabilty is more important that maximum efficiency for some folk.

As I said, I've never had one fail. And surely, if the heating works and the water doesn't, to anyone with an ounce of common sense, this means the problem lies with something which is not common to both.

--
http://petersparrots.com
http://petersphotos.com

Auctioneer, n. The man who proclaims with a hammer that he has picked a pocket with his tongue.

On Wed, 30 Nov 2011 14:14:45 -0000, David WE Roberts wrote:


"Tim Downie" wrote in message
...
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler.
Pumps generally last a lot longer (or at least they used to) than
motorised valves where problems with either the motors or the switches are
relatively common.

snip

two houses ago I was on 'C' plan and it worked very well.
I had a Parkray anthracite bean boiler for heating the living room, hot
water and radiators during the colder months.
I also had a Raeburn cooker with a back boiler which we used for heating the
kitchen and for cooking for most of the year.
This also gave us "free" hot water.

Now with older style solid fuel back boilers you don't want any valves to
restrict the circulation of the hot water from the back boiler to the hot
water tank or you could build up a head of steam - a couple of times we
forgot to shut the damper on the raeburn and managed to boil up the hot
water tank in the middle of the night.

The Parkray was fine, because it had a thermostatic damper.

I can't remember now if the two gravity systems were linked or if we had two
coils in the tank.
I suspect the two boilers were linked up near the tank.

So perhaps no point on modern systems (apart from simplicity) but with less
sophisticated heat sources the 'C' plan can work well.

Thinking on this, how are solid fuel stoves with back boilers linked into
heating systems these days?
Gravity feed to a heat store?

Cheers

Dave R

That sounds far too complicated. I simply have a gas boiler, a pump, two valves (plus one for the garage heating but nevermind), and a bunch of radiators and a hot water tank. I can choose exactly what I want when I want. I actually hardly ever use hot water so I have a manual switch for that, and the heating I leave on 24/365 at the room temperature I want, and it simply doesn't fire up in summer.

--
http://petersparrots.com
http://petersphotos.com

A guy bought his wife a beautiful diamond ring for Christmas.
A friend of his said, "I thought she wanted one of those sporty 4-Wheel drive vehicles."
"She did," he replied. "But where in the hell was I gonna find a fake Jeep?"

Lieutenant Scott wrote:
And surely, if the heating works
and the water doesn't, to anyone with an ounce of common sense, this
means the problem lies with something which is not common to both.


I am afraid that particular nuance is only available to PHd philosophers
and logicians these days.

Mostly if the heating works and the hot water doesn't, its

- the governments fault, and they should Do Something
- global warming and the government should Do Something.
- to difficult for my pretty little head so I will Get A Man In And Sell
My Body.
- too difficult for my thick chav brain so I will trash the boiler, and
the whole house, and get some new social housing on the basis that this
one isn't fit to inhabit.
- all Gods Will so I will pray hard and trust in Jesus.
- down to my Karma, so I will light a scented candle and try not to
think of Angelina Jolie's bum while I do the spiritual masturbation bit.

I mean Scotty, what is the POINT of being clever and right, if you are
still going to get ****ed over by someone somewhere..and complaining
very hard to people who are paid to listen is infinitely more fun than
putting spanner to pipe.

On Wed, 30 Nov 2011 16:01:36 -0000, The Natural Philosopher wrote:

Lieutenant Scott wrote:
And surely, if the heating works
and the water doesn't, to anyone with an ounce of common sense, this
means the problem lies with something which is not common to both.


I am afraid that particular nuance is only available to PHd philosophers
and logicians these days.

Mostly if the heating works and the hot water doesn't, its

- the governments fault, and they should Do Something
- global warming and the government should Do Something.
- to difficult for my pretty little head so I will Get A Man In And Sell
My Body.
- too difficult for my thick chav brain so I will trash the boiler, and
the whole house, and get some new social housing on the basis that this
one isn't fit to inhabit.
- all Gods Will so I will pray hard and trust in Jesus.
- down to my Karma, so I will light a scented candle and try not to
think of Angelina Jolie's bum while I do the spiritual masturbation bit.

I mean Scotty, what is the POINT of being clever and right, if you are
still going to get ****ed over by someone somewhere..and complaining
very hard to people who are paid to listen is infinitely more fun than
putting spanner to pipe.

A+ for that answer son, take tomorrow's lesson off.

--
http://petersparrots.com
http://petersphotos.com

I take loads of laxatives when the pollen count rises. It stops me sneezing - I daren't.

"Lieutenant Scott" wrote in message
newsp.v5rmytu1ytk5n5@i7-940...
On Wed, 30 Nov 2011 14:14:45 -0000, David WE Roberts
wrote:


"Tim Downie" wrote in message
...
Lieutenant Scott wrote:
big snip
Now with older style solid fuel back boilers you don't want any valves to
restrict the circulation of the hot water from the back boiler to the hot
water tank or you could build up a head of steam - a couple of times we
forgot to shut the damper on the raeburn and managed to boil up the hot
water tank in the middle of the night.

The Parkray was fine, because it had a thermostatic damper.

I can't remember now if the two gravity systems were linked or if we had
two
coils in the tank.
I suspect the two boilers were linked up near the tank.

So perhaps no point on modern systems (apart from simplicity) but with
less
sophisticated heat sources the 'C' plan can work well.

Thinking on this, how are solid fuel stoves with back boilers linked into
heating systems these days?
Gravity feed to a heat store?

*That sounds far too complicated. I simply have a gas boiler, a pump, two
valves (plus one for the garage heating but nevermind), and a *bunch of
radiators and a hot water tank. I can choose exactly what I want when I
want. I actually hardly ever use hot water so I have a *manual switch for
that, and the heating I leave on 24/365 at the room temperature I want, and
it simply doesn't fire up in summer.

Err......fine if you have mains gas.
If you are not connected to mains gas then your options are more limited
If you chose solid fuel with back boilers on stoves and/or cookers then you
need a different system.

--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

(\__/)
(='.'=)
(")_(")

Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler.
Pumps generally last a lot longer (or at least they used to) than
motorised valves where problems with either the motors or the
switches are relatively common.


A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan

When HW is not called for via the cylinder stat or programmer then the valve
for the HW is closed.

--
Adam

* Sometimes I like to lay in my neighbours garden and pretend to be a
carrot *

On Wed, 30 Nov 2011 17:03:00 -0000, David WE Roberts wrote:


"Lieutenant Scott" wrote in message
newsp.v5rmytu1ytk5n5@i7-940...
On Wed, 30 Nov 2011 14:14:45 -0000, David WE Roberts
wrote:


"Tim Downie" wrote in message
...
Lieutenant Scott wrote:
big snip
Now with older style solid fuel back boilers you don't want any valves to
restrict the circulation of the hot water from the back boiler to the hot
water tank or you could build up a head of steam - a couple of times we
forgot to shut the damper on the raeburn and managed to boil up the hot
water tank in the middle of the night.

The Parkray was fine, because it had a thermostatic damper.

I can't remember now if the two gravity systems were linked or if we had
two
coils in the tank.
I suspect the two boilers were linked up near the tank.

So perhaps no point on modern systems (apart from simplicity) but with
less
sophisticated heat sources the 'C' plan can work well.

Thinking on this, how are solid fuel stoves with back boilers linked into
heating systems these days?
Gravity feed to a heat store?

*That sounds far too complicated. I simply have a gas boiler, a pump, two
valves (plus one for the garage heating but nevermind), and a *bunch of
radiators and a hot water tank. I can choose exactly what I want when I
want. I actually hardly ever use hot water so I have a *manual switch for
that, and the heating I leave on 24/365 at the room temperature I want, and
it simply doesn't fire up in summer.

Err......fine if you have mains gas.
If you are not connected to mains gas then your options are more limited
If you chose solid fuel with back boilers on stoves and/or cookers then you
need a different system.

I'd choose an electric boiler, or to save money a heat pump. I like the operation to be simple.

--
http://petersparrots.com
http://petersphotos.com

Barber: "Your hair is getting gray."
Customer: "Try cutting a little faster."

On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth wrote:

Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler.
Pumps generally last a lot longer (or at least they used to) than
motorised valves where problems with either the motors or the
switches are relatively common.


A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan

When HW is not called for via the cylinder stat or programmer then the valve
for the HW is closed.

Can you therefore have:

HW only
heating only
Both?

--
http://petersparrots.com
http://petersphotos.com

"I have left orders to be awakened at any time in case of national emergency, even if I'm in a cabinet meeting." - Ronald Reagan

"Lieutenant Scott" wrote in message newsp.v5rmrprvytk5n5@i7-940...
Well obviously everyone's mileage with vary. I've had two motors fail in the last 15 years.

Tim

Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:
Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger
in the hot water tank. Another goes to the radiators in the
house, the other goes to radiators in the garage (I converted it
to a parrot aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have
a choice, you have to heat the water when you heat the house (or
is it the other way round?). My parents boiler is set up so they
have to heat the water when they heat the house. What if the
house is too cold, but you aren't planning on taking a bath that
day? I know the heat from the tank will eventually seep out into
the house, or get used later as hot water, but it seems daft to
throw heat into something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part
outside the boiler. Pumps generally last a lot longer (or at least
they used to) than motorised valves where problems with either the
motors or the switches are relatively common.


A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan

When HW is not called for via the cylinder stat or programmer then
the valve for the HW is closed.

Can you therefore have:

HW only
heating only
Both?

You can have HW only or CH only or both at the same time with a correctly
installed C Plan.

--
Adam

* Sometimes I like to lay in my neighbours garden and pretend to be a
carrot *

On 30/11/2011 18:47, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:




A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan


When HW is not called for via the cylinder stat or programmer then the
valve
for the HW is closed.

Can you therefore have:

HW only
heating only
Both?


YES! That's precisely the point of it. With a 'conventional' gravity HW
and pumped CH system (which was what you initially described), you can't
- you have to run the boiler to make the CH work, and that heats the HW
whether you want it or not.

BUT, convert it to a C-Plan, and that all changes. A C-Plan system has a
motorised valve in the gravity HW circuit and a thermostat on the HW
cylinder. The auxiliary switch on the valve (which needs to be of the
change-over variety) is wired in a cunning way which provides the following:
HW only: Valve opens, boiler runs until cylinder stat satisfied, then
boiler shuts down
CH only: Valve closes, boiler and pump run until room stat satisfied,
then boiler and pump shut down
Both: Valve opens, boiler and pump run. As soon as HW or CH demand
satisfied, system operates as per CH only or HW only, as appropriate.
When both demands are satisfied, the system shuts down.

I don't think that anyone would install a C-Plan system from scratch (in
preference to an S-Plan or Y-Plan) but it's good way of converting a
gravity HW system in order to provide independent control of HW and CH,
plus boiler interlock, without too much upheaval.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Nov 30, 9:12*am, "Lieutenant Scott" wrote:
I think I'm using the correct terminology here, forgive me if I'm not....

I have S-plan - hot water comes out the boiler, through the pump, then divides into three (it was two, but I modified it!) to go through three independent valves. *One goes to the heat exchanger in the hot water tank. *Another goes to the radiators in the house, the other goes to radiators in the garage (I converted it to a parrot aviary, and electric heating is expensive!).

My question is, what is the point of C-plan - where you don't have a choice, you have to heat the water when you heat the house (or is it the other way round?). *My parents boiler is set up so they have to heat the water when they heat the house. *What if the house is too cold, but you aren't planning on taking a bath that day? *I know the heat from the tank will eventually seep out into the house, or get used later as hot water, but it seems daft to throw heat into something you don't want right now.

--http://petersparrots.comhttp://petersphotos.com

The 2 most common elements in the universe are hydrogen and stupidity.

"Proper" C Plan uses a motorised valve in the gravity primary which
limits the temperature of the hot water cylinder.
See http://www.honeywelluk.com/products/...undial-C-Plan/
A dump radiator or towel rail is the norm to keep towels dry and
accomodate boiler heat dissipation. I think you are talking about a
simple gravity primary with pumped radiator circuit

On 30/11/2011 11:32, Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves are
required. As you've worked out, it means that you don't have fully
independant control of your HW and CH systems *but*, it is simple and
reliable with the pump being the only moving part outside the boiler.
Pumps generally last a lot longer (or at least they used to) than
motorised valves where problems with either the motors or the switches
are relatively common.

In these days of higher fuel costs and possibly higher HW consumption,
fully pumped systems with motorised valves make more sense for 99% of
the population who want as stored HW system but the simplicity and
reliability of the old systems may be valued more by folk who don't use
a lot of HW.

Tim
When I moved into this house in 1979 I realised that the two motorised
valves installed made the DHW and CH capable of independent operation.
The only thing that prevented the DHW from running without the CH was
the mechanical Randall timeclock (oh look, they still make them
http://tinyurl.com/6u4v2kj )
So I augmented it with two rotary 3 position switches,
DHW=timed-off-constant & CH=timed-off-constant
A toggle switch on the same panel marked BOOST shorted out the cylinder
stat before bathtime.

--

Graham.

%Profound_observation%

Roger Mills wrote:
I don't think that anyone would install a C-Plan system from scratch
(in preference to an S-Plan or Y-Plan) but it's good way of
converting a gravity HW system in order to provide independent
control of HW and CH, plus boiler interlock, without too much
upheaval.

You probably could not install one on a new system due to Part L.

But as you said, you would be able to install a C Plan as a conversion on an
existing gravity (uncontrolled?) HW system.

--
Adam

* Sometimes I like to lay in my neighbours garden and pretend to be a
carrot *

In message op.v5q47xdyytk5n5@i7-940, Lieutenant Scott
writes

My question is, what is the point of C-plan

No point whatsoever. No-one buys crappy teak laminate furniture these
days ...

--
Graeme

On Fri, 02 Dec 2011 13:58:57 -0000, News wrote:

In message op.v5q47xdyytk5n5@i7-940, Lieutenant Scott
writes

My question is, what is the point of C-plan

No point whatsoever. No-one buys crappy teak laminate furniture these
days ...

Hhahahahaahah!!!!

G-plan is ok.

--
http://petersparrots.com
http://petersphotos.com

A gang-member was holding his 8-month-old baby while his wife was in kitchen fixing lunch.
The baby murmured "mother".
The guy gets all excited and hollered to his wife "Hey, the baby just said half a word!"

On Wed, 30 Nov 2011 19:25:41 -0000, ARWadsworth wrote:

Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:
Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger
in the hot water tank. Another goes to the radiators in the
house, the other goes to radiators in the garage (I converted it
to a parrot aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have
a choice, you have to heat the water when you heat the house (or
is it the other way round?). My parents boiler is set up so they
have to heat the water when they heat the house. What if the
house is too cold, but you aren't planning on taking a bath that
day? I know the heat from the tank will eventually seep out into
the house, or get used later as hot water, but it seems daft to
throw heat into something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part
outside the boiler. Pumps generally last a lot longer (or at least
they used to) than motorised valves where problems with either the
motors or the switches are relatively common.


A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan

When HW is not called for via the cylinder stat or programmer then
the valve for the HW is closed.

Can you therefore have:

HW only
heating only
Both?

You can have HW only or CH only or both at the same time with a correctly
installed C Plan.

I fail to see why someone could go to the trouble of making it so you couldn't.

--
http://petersparrots.com
http://petersphotos.com

Mrs. Jones is having her house painted, and her husband comes home from work and leans against the freshly painted wall.
The next day, she says to the painter, "You wanna see where my husband put his hand last night?"
He sighs and says, "Look lady, I got a tough day's work ahead of me. Why don't you just make us a cup of tea?"

On 27/12/2011 01:40, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 19:25:41 -0000, ARWadsworth
wrote:

Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:
Tim Downie wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger
in the hot water tank. Another goes to the radiators in the
house, the other goes to radiators in the garage (I converted it
to a parrot aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have
a choice, you have to heat the water when you heat the house (or
is it the other way round?). My parents boiler is set up so they
have to heat the water when they heat the house. What if the
house is too cold, but you aren't planning on taking a bath that
day? I know the heat from the tank will eventually seep out into
the house, or get used later as hot water, but it seems daft to
throw heat into something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part
outside the boiler. Pumps generally last a lot longer (or at least
they used to) than motorised valves where problems with either the
motors or the switches are relatively common.


A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan


When HW is not called for via the cylinder stat or programmer then
the valve for the HW is closed.

Can you therefore have:

HW only
heating only
Both?

You can have HW only or CH only or both at the same time with a correctly
installed C Plan.

I fail to see why someone could go to the trouble of making it so you
couldn't.

Some systems were converted from older designs such as gravity feed -
hence you don't always get the choice.

Some modern systems actually work better with HW priority - i.e. using a
diversion valve rather than a mid position one. In cases where you have
a fast recovery cylinder that is able to absorb heat at the rate the
boiler can produce it, (many traditional cylinders can only heat at
around 5kW) it can make sense to give it the full output until warm, and
then divert back to the heating. Suits places with high hot water
demands, and also those with modern condensers running split temperature
operation (esp with weather compensation). The the boiler can run a hot
preset flow temperature for reheating the cylinder, and a variable flow
temperature appropriate for the heating load.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 27/12/2011 17:05, John Rumm wrote:
On 27/12/2011 01:40, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 19:25:41 -0000, ARWadsworth
wrote:


You can have HW only or CH only or both at the same time with a
correctly
installed C Plan.

I fail to see why someone could go to the trouble of making it so you
couldn't.


I don't suppose they would do so intentionally. They might still foul it
up though!

Some systems were converted from older designs such as gravity feed -
hence you don't always get the choice.


You wouldn't have the choice *until* you converted to C-Plan - then you
would.

Some modern systems actually work better with HW priority - i.e. using a
diversion valve rather than a mid position one. In cases where you have
a fast recovery cylinder that is able to absorb heat at the rate the
boiler can produce it, (many traditional cylinders can only heat at
around 5kW) it can make sense to give it the full output until warm, and
then divert back to the heating. Suits places with high hot water
demands, and also those with modern condensers running split temperature
operation (esp with weather compensation). The the boiler can run a hot
preset flow temperature for reheating the cylinder, and a variable flow
temperature appropriate for the heating load.


All good stuff - but not relevant to C-Plan systems which *still* have
gravity HW circuits. What you have discussed is the relative merits of
Y-Plan vs W-Plan - both of which are fully pumped.

--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

"Tim Downie" wrote in message
...
Lieutenant Scott wrote:
On Wed, 30 Nov 2011 11:32:38 -0000, Tim Downie
wrote:
Lieutenant Scott wrote:
I think I'm using the correct terminology here, forgive me if I'm
not....
I have S-plan - hot water comes out the boiler, through the pump,
then divides into three (it was two, but I modified it!) to go
through three independent valves. One goes to the heat exchanger in
the hot water tank. Another goes to the radiators in the house, the
other goes to radiators in the garage (I converted it to a parrot
aviary, and electric heating is expensive!).
My question is, what is the point of C-plan - where you don't have a
choice, you have to heat the water when you heat the house (or is it
the other way round?). My parents boiler is set up so they have to
heat the water when they heat the house. What if the house is too
cold, but you aren't planning on taking a bath that day? I know the
heat from the tank will eventually seep out into the house, or get
used later as hot water, but it seems daft to throw heat into
something you don't want right now.

The "point" is that it's an archaic system that relies on gravity
circulation to heat the water and consequently no motorised valves
are required. As you've worked out, it means that you don't have
fully independant control of your HW and CH systems *but*, it is
simple and reliable with the pump being the only moving part outside
the boiler. Pumps generally last a lot longer (or at least they
used to) than motorised valves where problems with either the motors
or the switches are relatively common. In these days of higher fuel
costs and possibly higher HW
consumption, fully pumped systems with motorised valves make more
sense for 99% of the population who want as stored HW system but the
simplicity and reliability of the old systems may be valued more by
folk who don't use a lot of HW.

Oh I see. Thanks. I've never had a problem with the two motorized
valves in the 10 years I've been here. And a replacement valve is
only £20 anyway (that's what I paid for the third one I just added -
in fact even less if you just replace the motor/switch unit).

As you say, motorised valves aren't really a big issue for DIYers but they
could be a major cause of expense and inconvenience to non-DIYers. You
only need to read a few "My combis stopped working!" threads to realise
sometimes reliabilty is more important that maximum efficiency for some
folk.

Then get an Intergas combi with only 4 moving parts. No 3-way valve, the DHW
works when the pump packs up, A standard B&Q available Grundfos is used. You
do not need water in the CH for the DHW to work. The pump does not spin
when calling DHW. Unbustable. Ultra reliable.

"John Rumm" wrote in message
news
Some modern systems actually work better with HW priority - i.e. using a
diversion valve rather than a mid position one. In cases where you have a
fast recovery cylinder that is able to absorb heat at the rate the boiler
can produce it, (many traditional cylinders can only heat at around 5kW)
it can make sense to give it the full output until warm, and then divert
back to the heating.

Best to have a direct cylinder - cheaper. Heat it via an external plate
heat exchanger - the plate replaces the coil. Then have a bronze pump on
the fresh water side pumping into the top of the cylinder from the bottom
via the plate. The cylinder can be down-sized by 1/3 as the hot water is
dumped at the top of the cylinder. Re-heat is super fast and DHW is
available for say basin use within a minute of so from cold. The bigger the
boiler the better as all the heat from the boiler is dumped into the
cylinder. The bigger the boiler the smaller the cylinder. The boiler may be
dumping more heat into the top of the cylinder than what is being draw-off.

Using a cheaper "direct" unvented cylinder an Integas combi can be used to
heat the cylinder using a bronze pump. Same again as above in smaller
cylinder, etc. Much cheaper, simpler installation taking up less space. I
have done the figures.....and a far superior system.

On 28/12/2011 10:11, Roger Mills wrote:

On 27/12/2011 17:05, John Rumm wrote:

All good stuff - but not relevant to C-Plan systems which *still* have
gravity HW circuits. What you have discussed is the relative merits of
Y-Plan vs W-Plan - both of which are fully pumped.

Yes that's a fair cop... I will get my coat!


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be used
to heat the cylinder using a bronze pump. Same again as above in smaller
cylinder, etc. Much cheaper, simpler installation taking up less space.
I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be
used to heat the cylinder using a bronze pump. Same again as above
in smaller cylinder, etc. Much cheaper, simpler installation taking
up less space. I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

No, they just have the prettiest pictures in the catalogue.

--
Adam

"John Rumm" wrote in message
o.uk...
On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be used
to heat the cylinder using a bronze pump. Same again as above in smaller
cylinder, etc. Much cheaper, simpler installation taking up less space.
I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

You obviously have never heard of them. Atmos rebadged them and sold in the
UK in a small way. They are the best, but limited in flow rate to around 15
litres/min depending on model. They are pushing them big in the UK now under
the original Dutch Intergas badge. Want a reliable combi that delivers with
outside temp compensation as standard and OpenTherm? Then Intergas cannot
be beaten. They are cost effective. They just do not go wrong. Simple
robust engineering. The whole of the back panel is the heat exchanger.

They can be open vented using an F&E tank with combined feed & expansion.
Then no external pressure relief valve is needed running through wall.

I put two of them in large house One doing CH up and one downstairs. One
doing one bathroom and one the other. The DHW was combined using check
valves and a small shock arrestor for the two baths. Compared to a large
space consuming unvented cylinder and all the zone valve paraphernalia, tat
can go wrong, it is very cheap - I have done the figures. Also heating
backup in the house as well. Always a winner on cost to install & run and in
use.

"ARWadsworth" wrote in message
...
John Rumm wrote:
On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be
used to heat the cylinder using a bronze pump. Same again as above
in smaller cylinder, etc. Much cheaper, simpler installation taking
up less space. I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

No, they just have the prettiest pictures in the catalogue.

It is best you stick to ferrets.

On 28/12/2011 15:52, Doctor Drivel wrote:

"ARWadsworth" wrote in message
...
John Rumm wrote:
On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be
used to heat the cylinder using a bronze pump. Same again as above
in smaller cylinder, etc. Much cheaper, simpler installation taking
up less space. I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

No, they just have the prettiest pictures in the catalogue.

It is best you stick to ferrets.

better than sticking to catalogues eh?

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
o.uk...
On 28/12/2011 15:52, Doctor Drivel wrote:

"ARWadsworth" wrote in message
...
John Rumm wrote:
On 28/12/2011 14:43, Doctor Drivel wrote:

Using a cheaper "direct" unvented cylinder an Integas combi can be
used to heat the cylinder using a bronze pump. Same again as above
in smaller cylinder, etc. Much cheaper, simpler installation taking
up less space. I have done the figures.....and a far superior system.

So are Integas offering the best kickback this month?

No, they just have the prettiest pictures in the catalogue.

It is best you stick to ferrets.

better than sticking to catalogues eh?

Ferrets eat them. Stick to DIY leave the real stuff to the pros.

On Wed, 30 Nov 2011 18:53:06 -0000, Tim Downie wrote:


"Lieutenant Scott" wrote in message newsp.v5rmrprvytk5n5@i7-940...

Quote:

As I said, I've never had one fail. And surely, if the heating works and the water doesn't, to anyone with an ounce of common sense, this means the problem lies with something which is not common to both.

Well obviously everyone's mileage with vary. I've had two motors fail in the last 15 years.

Tim

That's not the end of the world is it?

Did I mention my boiler hasn't been serviced or repaired at all since 1999?

--
http://petersparrots.com
http://petersphotos.com

A male gynecologist is like an auto mechanic who never owned a car.

On Wed, 30 Nov 2011 20:13:10 -0000, Roger Mills wrote:

On 30/11/2011 18:47, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:




A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan


When HW is not called for via the cylinder stat or programmer then the
valve
for the HW is closed.

Can you therefore have:

HW only
heating only
Both?


YES! That's precisely the point of it. With a 'conventional' gravity HW
and pumped CH system (which was what you initially described), you can't
- you have to run the boiler to make the CH work, and that heats the HW
whether you want it or not.

Mine does this very simply, one valve for the hot water, one for the heating. You can't have three choices with a valve with two positions!

BUT, convert it to a C-Plan, and that all changes. A C-Plan system has a
motorised valve in the gravity HW circuit and a thermostat on the HW
cylinder. The auxiliary switch on the valve (which needs to be of the
change-over variety) is wired in a cunning way which provides the following:
HW only: Valve opens, boiler runs until cylinder stat satisfied, then
boiler shuts down
CH only: Valve closes, boiler and pump run until room stat satisfied,
then boiler and pump shut down
Both: Valve opens, boiler and pump run. As soon as HW or CH demand
satisfied, system operates as per CH only or HW only, as appropriate.
When both demands are satisfied, the system shuts down.

What causes the difference in operation between HW only and HW + CH?

I don't think that anyone would install a C-Plan system from scratch (in
preference to an S-Plan or Y-Plan) but it's good way of converting a
gravity HW system in order to provide independent control of HW and CH,
plus boiler interlock, without too much upheaval.

--
http://petersparrots.com
http://petersphotos.com

The New York Times, among other papers, recently published a new Hubble photograph of distant galaxies colliding.
Of course, astronomers have had pictures of colliding galaxies for quite some time now, but with the vastly improved resolution provided by the Hubble Space Telescope, you can actually see the lawyers rushing to the scene...

On 31/12/2011 17:50, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 20:13:10 -0000, Roger Mills
wrote:

On 30/11/2011 18:47, Lieutenant Scott wrote:

Can you therefore have:

HW only
heating only
Both?


YES! That's precisely the point of it. With a 'conventional' gravity HW
and pumped CH system (which was what you initially described), you can't
- you have to run the boiler to make the CH work, and that heats the HW
whether you want it or not.

Mine does this very simply, one valve for the hot water, one for the
heating. You can't have three choices with a valve with two positions!

BUT, convert it to a C-Plan, and that all changes. A C-Plan system has a
motorised valve in the gravity HW circuit and a thermostat on the HW
cylinder. The auxiliary switch on the valve (which needs to be of the
change-over variety) is wired in a cunning way which provides the
following:
HW only: Valve opens, boiler runs until cylinder stat satisfied, then
boiler shuts down
CH only: Valve closes, boiler and pump run until room stat satisfied,
then boiler and pump shut down
Both: Valve opens, boiler and pump run. As soon as HW or CH demand
satisfied, system operates as per CH only or HW only, as appropriate.
When both demands are satisfied, the system shuts down.

What causes the difference in operation between HW only and HW + CH?

HW only just first the boiler, but not the pump until the cylinder stat
is satisfied. HW+CH runs the pump as well.

http://wiki.diyfaq.org.uk/images/6/6c/C-Plan-Wiring.gif

I don't think that anyone would install a C-Plan system from scratch (in
preference to an S-Plan or Y-Plan) but it's good way of converting a
gravity HW system in order to provide independent control of HW and CH,
plus boiler interlock, without too much upheaval.

Yup, its entire raison d'être...


--
Cheers,

John.

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On 31/12/2011 17:50, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 20:13:10 -0000, Roger Mills
wrote:

On 30/11/2011 18:47, Lieutenant Scott wrote:
On Wed, 30 Nov 2011 17:57:01 -0000, ARWadsworth
wrote:




A C Plan is independant HW and CH and does use a motorised valve. See

http://wiki.diyfaq.org.uk/index.php?...ty_DHW:_C-Plan



When HW is not called for via the cylinder stat or programmer then the
valve
for the HW is closed.

Can you therefore have:

HW only
heating only
Both?


YES! That's precisely the point of it. With a 'conventional' gravity HW
and pumped CH system (which was what you initially described), you can't
- you have to run the boiler to make the CH work, and that heats the HW
whether you want it or not.

Mine does this very simply, one valve for the hot water, one for the
heating. You can't have three choices with a valve with two positions!

All together now - OH YES YOU CAN!! You're forgetting that the pump also
comes into the equation, but - in a gravity HW and pumped CH system
(which is where C-Plan is used) is only used for the CH. Thus:
Boiler on, Valve open, pump off - HW only
Boiler on, valve closed, pump on - CH only
Boiler on, valve open, pump on - both together

*I* make that *three* - what say *you*?

Presumably your system is fully pumped and is thus not relevant to a
discussion about C-Plan.

BUT, convert it to a C-Plan, and that all changes. A C-Plan system has a
motorised valve in the gravity HW circuit and a thermostat on the HW
cylinder. The auxiliary switch on the valve (which needs to be of the
change-over variety) is wired in a cunning way which provides the
following:
HW only: Valve opens, boiler runs until cylinder stat satisfied, then
boiler shuts down
CH only: Valve closes, boiler and pump run until room stat satisfied,
then boiler and pump shut down
Both: Valve opens, boiler and pump run. As soon as HW or CH demand
satisfied, system operates as per CH only or HW only, as appropriate.
When both demands are satisfied, the system shuts down.

What causes the difference in operation between HW only and HW + CH?


The PUMP - see above. If you want to understand it, you'll need to study
the C-Plan circuit diagram shown in the reference above. The valve's
auxiliary change-over switch is the cunning bit to watch. When there is
only a CH demand - so that the valve is closed - the programmer/room
stat switch the pump and the contacts in the valve switch the boiler.
--
Cheers,
Roger
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