I'm beginning to despair with my 12yo Alpha combi boiler, so am thinking
of replacing it.
Rather than go with the recommendations of the fitter (if I do employ a
fitter, I may diy), I would rather have a few opinions on what is the
current best value/most reliable boiler out there.
Pretty low consumption - only 6 rads, though i do like to have a shower
when I get home from work, so must be able to deliver enough water. My
current one is 24kw iirc, and has been generally fine delivering hot
water.

Thanks for any thoughts.
Alan.
--
To reply by e-mail, change the ' + ' to 'plus'.

On Thu, 16 Oct 2008 20:19:58 +0100, A.Lee wrote:

I'm beginning to despair with my 12yo Alpha combi boiler, so am thinking
of replacing it.
Rather than go with the recommendations of the fitter (if I do employ a
fitter, I may diy), I would rather have a few opinions on what is the
current best value/most reliable boiler out there.
Pretty low consumption - only 6 rads, though i do like to have a shower
when I get home from work, so must be able to deliver enough water. My
current one is 24kw iirc, and has been generally fine delivering hot
water.

Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors. They're
at the lower end of the price range for decent boilers (cf Vaillant)
and W-B don't have any reliability issues with their boilers (not that I
know of anyway) or have blotted their copybook giving victims of
boilers with disastrous reliability problems the runaround denying the
problem exists (Google "Potterton Suprima problem").

If you DIY with a fitter for the gas stuff get your person lined up before
you start and make sure they're happy with the arrangement, rather than
expecting to get someone in when you've already done some of the work.

--
YAPH http://yaph.co.uk

What do you mean, talking about it isn't oral sex?

On Oct 16, 8:54*pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors. They're
at the lower end of the price range for decent boilers (cf Vaillant)
and W-B don't have any reliability issues with their boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.

Dave Starling wrote:
On Oct 16, 8:54 pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors.
They're at the lower end of the price range for decent boilers (cf
Vaillant) and W-B don't have any reliability issues with their
boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.


Am I right in thinking that Vaillant is still the make of choice if price no
object (within reason)?

In article ,
GB wrote:
Dave Starling wrote:
On Oct 16, 8:54 pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors.
They're at the lower end of the price range for decent boilers (cf
Vaillant) and W-B don't have any reliability issues with their
boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.


Am I right in thinking that Vaillant is still the make of choice if
price no object (within reason)?

What about Viessmann? I've recently installed mine - a system boiler - and
it's beautifully made. They do a similar combi.

--
*How do you tell when you run out of invisible ink? *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) coughed up some electrons that declared:

In article ,
GB wrote:
Dave Starling wrote:
On Oct 16, 8:54 pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors.
They're at the lower end of the price range for decent boilers (cf
Vaillant) and W-B don't have any reliability issues with their
boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.


Am I right in thinking that Vaillant is still the make of choice if
price no object (within reason)?

What about Viessmann? I've recently installed mine - a system boiler - and
it's beautifully made. They do a similar combi.


I'm glad to hear that as I've asked the local gas fitter to quote for a
Vitodens 100 Compact (he's also on the Viessmann list of trained
installers).

He did spend some time trying to sell me a weather compensation system and a
pressurised system, though once I'd knocked it into him that I was
specifying both a vented and a braindead but efficient and reliable boiler
to drive a heatbank, he gracefully gave up and recommended the 100 which
concurred with what I already thought.

Wait to see what his quote looks like...

Cheers

Tim

A.Lee wrote:
I'm beginning to despair with my 12yo Alpha combi boiler, so am
thinking of replacing it.
Rather than go with the recommendations of the fitter (if I do employ
a fitter, I may diy), I would rather have a few opinions on what is
the current best value/most reliable boiler out there.
Pretty low consumption - only 6 rads, though i do like to have a
shower when I get home from work, so must be able to deliver enough
water. My current one is 24kw iirc, and has been generally fine
delivering hot water.

Thanks for any thoughts.
Alan.

We had an Alpha CD32C fitted about two and a half years ago and it's been
brilliant. Mind you, only about 6 months of the 3-year warranty left so
we'll see what happens then )

In article ,
Tim S wrote:
What about Viessmann? I've recently installed mine - a system boiler -
and it's beautifully made. They do a similar combi.


I'm glad to hear that as I've asked the local gas fitter to quote for a
Vitodens 100 Compact (he's also on the Viessmann list of trained
installers).

He did spend some time trying to sell me a weather compensation system
and a pressurised system, though once I'd knocked it into him that I was
specifying both a vented and a braindead but efficient and reliable
boiler to drive a heatbank, he gracefully gave up and recommended the
100 which concurred with what I already thought.

I hedged my bets by installing both weather compensated and a room stat -
and can swop between them in software. Not had poor enough weather to
decide which one works best in this Victorian house with solid walls -
otherwise well insulated.

My Vitodens 200 system came with an internal pressure vessel for the
primary so I converted from open vent - but kept the header tank fed hot
water system.

Wait to see what his quote looks like...

--
*i souport publik edekashun.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) coughed up some electrons that declared:


My Vitodens 200 system came with an internal pressure vessel for the
primary so I converted from open vent - but kept the header tank fed hot
water system.


Heh - I'm working the other way around, mains pressure hot water and vented
rads/boiler primary. Hot water may be limited as I'm measuring about 35-50
l/min flow rate at the mains (through a tap, so it's probably actually a
bit better, calculations suggest it should be nearer 50 l/min). But later
on (when I have a reason to dig holes in the drive) I can uprate the mains
pipe if I want.

My feeling is that if I'm using a heatbank, it will be better (=more
efficient/faster) to offload the boiler's output directly into the mass of
water in the heatbank and not put a coil in the way, especially at the
temperature that the boiler likes (fitter said output max of 65C for best
effect). My theory anyway... And I don't mind a little header tank in the
roof - somewhere to put the chemicals in easily.

He was also trying to sell me a magnetic magnetite trap - never seen one
before. Have you?

I'm going to put the cheapest 210 or so litre DPS heatbank in I can manage
(price varies massively with short and fat vs. tall and thin and I'm
building the space to house it, so I get to choose the cheaper format,
which apparently is tall and thin).

Boiler control will be a simple hysteresis loop (with a very simple DIY'd
relay logic controller) between twin tank stats and possibly a timeswitch
to knock it off overnight (this may be pointless - once the tank is hot, I
reckon it ought to manage to stay within the hysteresis loop for 6 or more
hours)

Hot water is demand driven and the rads will, provided I don't have any
budget-sucking problems with something else, be done with a Honeywell
CM-Zone controller (several zones, to be decided). I believe there is a
weather compensation bolt on for those, but I don't know if it's worth it.

Cheers

Tim

On Fri, 17 Oct 2008 01:34:38 -0700, Dave Starling wrote:

Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.

Was it one with the machined rectangular block of alloy heat exchanger
or the conical cast type?

--
YAPH http://yaph.co.uk

I've got nothing against racists - I just wouldn't want my daughter to marry one

In article ,
Tim S wrote:
My Vitodens 200 system came with an internal pressure vessel for the
primary so I converted from open vent - but kept the header tank fed
hot water system.


Heh - I'm working the other way around, mains pressure hot water and
vented rads/boiler primary.
[snip]

I'd check with Viessmann before going down this route. I've a feeling it
will invalidate the warranty. But can't be arsed digging out the
installation book at this time of night.

--
*Fax is stronger than fiction *

Dave Plowman London SW
To e-mail, change noise into sound.

On Oct 17, 9:08*pm, Tim S wrote:
CM-Zone controller (several zones, to be decided). I believe there is a
weather compensation bolt on for those, but I don't know if it's worth it..
Id recommend you get the CM-Zone through a merchant who will take it
back if you dont like it. My experience was that the head units were
noisy and would often do their exercise to measure the plunge of the
trv pin. Was loud enough to wake a light sleeper.
Also the range of the transmitters was much less than advertised -
some of the head signals weren't received through a couple of brick
walls.
Seems a great idea let down by poor execution. Thankfully PTS took it
back with no restocking charge. I'd say use standard trvs and
something like an s-plan setup and keep it simple/stupid.

Also re the Vitodens 100 - the heat exchanger is a right sod to vent,
even if the system is sealed. You need some way designed into the
system to pass mains pressure water through it when filling. Even then
it takes a good hour before the the flow switch will work ok for the
burner to light.

On Oct 17, 9:55*pm, YAPH wrote:
Was it one with the machined rectangular block of alloy heat exchanger
or the conical cast type?
Its the conical cast type. I think it was the same design style as the
buderus which WB bought out.

On Fri, 17 Oct 2008 15:58:43 -0700 (PDT), Dave Starling
wrote:

On Oct 17, 9:55*pm, YAPH wrote:
Was it one with the machined rectangular block of alloy heat exchanger
or the conical cast type?
Its the conical cast type. I think it was the same design style as the
buderus which WB bought out.

Whiteley Brothers?

--
Frank Erskine

Dave Plowman (News) coughed up some electrons that declared:


Heh - I'm working the other way around, mains pressure hot water and
vented rads/boiler primary.
[snip]

I'd check with Viessmann before going down this route. I've a feeling it
will invalidate the warranty. But can't be arsed digging out the
installation book at this time of night.


I'll be reading the installation manual too - but why do you think that
Dave?

I'm going for a boiler designed for open vented use and the mains pressure
water is generated in a heat exchanger by the heatbank - it's not a combi
boiler, if that's what you're thinking?

Cheers

Tim

Dave Starling coughed up some electrons that declared:

On Oct 17, 9:08*pm, Tim S wrote:
CM-Zone controller (several zones, to be decided). I believe there is a
weather compensation bolt on for those, but I don't know if it's worth
it.
Id recommend you get the CM-Zone through a merchant who will take it
back if you dont like it. My experience was that the head units were
noisy and would often do their exercise to measure the plunge of the
trv pin. Was loud enough to wake a light sleeper.

That's interesting - thanks for the warning. I *could* always by one
controller/HR80 pair and try it in our rented house for a while and see how
the family cope.

Also the range of the transmitters was much less than advertised -
some of the head signals weren't received through a couple of brick
walls.
Seems a great idea let down by poor execution. Thankfully PTS took it
back with no restocking charge. I'd say use standard trvs and
something like an s-plan setup and keep it simple/stupid.


What I'd love to do is make up a little embedded ethernet-mains relay and
another ethernet-thermostat+display+buttons panel, stick a pair in each
room (relay controlling a zone valve to the rad) and programme them to:

a) Be simple and locally controllable;

b) Respond to a central programmer, an "embedded" (form factor, but actually
a full on PC) system with an LCD panel running linux which provides a
central one-stop-shop for control and a web interface.

It wouldn't be that hard (I already do linux *and* AVR microcontroller
programming), but as always, it's finding the time...

Also re the Vitodens 100 - the heat exchanger is a right sod to vent,
even if the system is sealed. You need some way designed into the
system to pass mains pressure water through it when filling. Even then
it takes a good hour before the the flow switch will work ok for the
burner to light.

Perhaps it might be wise to have a well placed drain cock or two, which can
be used to blow some mains water in with a hose. Won't hurt the system,
it'll just end up coming out of the header tank overflow.

Ta

Tim

In article ,
Tim S wrote:
Also re the Vitodens 100 - the heat exchanger is a right sod to vent,
even if the system is sealed. You need some way designed into the
system to pass mains pressure water through it when filling. Even then
it takes a good hour before the the flow switch will work ok for the
burner to light.

Perhaps it might be wise to have a well placed drain cock or two, which
can be used to blow some mains water in with a hose. Won't hurt the
system, it'll just end up coming out of the header tank overflow.

If it's the same as the 200, it has a filler/drain already provided since
it's designed for a sealed system. I've had no problems filling mine
despite doing it several times. ;-) Bloody lead free solder.

--
*I have a degree in liberal arts -- do you want fries with that

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) coughed up some electrons that declared:

In article ,
Tim S wrote:
Also re the Vitodens 100 - the heat exchanger is a right sod to vent,
even if the system is sealed. You need some way designed into the
system to pass mains pressure water through it when filling. Even then
it takes a good hour before the the flow switch will work ok for the
burner to light.

Perhaps it might be wise to have a well placed drain cock or two, which
can be used to blow some mains water in with a hose. Won't hurt the
system, it'll just end up coming out of the header tank overflow.

If it's the same as the 200, it has a filler/drain already provided since
it's designed for a sealed system. I've had no problems filling mine
despite doing it several times. ;-) Bloody lead free solder.


Ah - found it in one of their documents:

"... Vitodens 100 Compact is perfect for new installations and boiler
replacements on traditional open vented systems such as ?S? & ?Y?
plan installations. Open vented systems make special
demands on the heat exchanger and all of these have been taken into
consideration in the design of the Vitodens 100 Compact, to ensure the
quality, performance and reliability you?d expect from a Viessmann boiler."

It seems many of the models are for sealed systems, but this one (the one
recommended and the one I was looking at) is the exception.

Thanks for raising it - it's good to check these things.

BTW, did you really need lead free solder? (Was it on the potable parts)
I'm using 60/40 on the heating and lead free only where I need to.

Cheers

Tim

On Sat, 18 Oct 2008 00:57:27 +0100, Frank Erskine wrote:

On Fri, 17 Oct 2008 15:58:43 -0700 (PDT), Dave Starling
wrote:

Its the conical cast type. I think it was the same design style as the
buderus which WB bought out.

Whiteley Brothers?

Worcester Bosch - pay attention in the back there! :-)

--
YAPH http://yaph.co.uk

Never believe anyone who claims to be a liar

In article ,
Tim S wrote:
If it's the same as the 200, it has a filler/drain already provided since
it's designed for a sealed system. I've had no problems filling mine
despite doing it several times. ;-) Bloody lead free solder.


Ah - found it in one of their documents:

"... Vitodens 100 Compact is perfect for new installations and boiler
replacements on traditional open vented systems such as ?S? & ?Y? plan
installations. Open vented systems make special demands on the heat
exchanger and all of these have been taken into consideration in the
design of the Vitodens 100 Compact, to ensure the quality, performance
and reliability you?d expect from a Viessmann boiler."

Right - I've looked at the instructions for the 200 and I was correct -
sealed only.

It seems many of the models are for sealed systems, but this one (the one
recommended and the one I was looking at) is the exception.

Thanks for raising it - it's good to check these things.

It is indeed. However, although I was against a sealed system I'm now
converted. Can't think of any advantage of open - apart from adding
inhibitor etc - but this is really not much more difficult using a
concentrate via a rad bleed. And it does make filling so much easier - no
airlocks. Of course the 200 includes an expansion vessel - so no
additional expense there apart from some pipework mods.

BTW, did you really need lead free solder? (Was it on the potable parts)
I'm using 60/40 on the heating and lead free only where I need to.

I ran out and it was all I could get. After discovering a couple of leaks
in 'awkward' joints and having to re-do them I went back to leaded.

--
*What was the best thing before sliced bread?

Dave Plowman London SW
To e-mail, change noise into sound.

On Fri, 17 Oct 2008 15:58:43 -0700, Dave Starling wrote:

Its the conical cast type. I think it was the same design style as the
buderus which WB bought out.

Ooo-er, I've been fitting a lot of those.

Why did you need to service one 3 years ago? They'd only just come out
then.

--
YAPH http://yaph.co.uk

The floggings will continue until morale improves

Dave Plowman (News) coughed up some electrons that declared:

In article ,
Tim S wrote:
Thanks for raising it - it's good to check these things.

snippety snoop

It is indeed. However, although I was against a sealed system I'm now
converted. Can't think of any advantage of open - apart from adding
inhibitor etc - but this is really not much more difficult using a
concentrate via a rad bleed. And it does make filling so much easier - no
airlocks. Of course the 200 includes an expansion vessel - so no
additional expense there apart from some pipework mods.

Hi Dave,

I'm not committed on paper yet. So, in the spirit of open-mindedness:

Question: I thought one couldn't work DIY on hot pressurised plumbing - and
that it needed to be checked every year? Did I get that wrong (that would
be a deciding factor for me)?

The other thing is that, DPS do do heatbanks for sealed systems, but
effectively you end up with lots of heat exchangers (assuming you run the
rads pressurised too) so it seemed to make things more complicated with at
least two different circuits to fill plus the cylinder itself which can't
be pressurised (IIRC they do one with a little integral header tank and
float valve, so we'll assume that should sort itself out).

Not sure how much it bungs the cost up to add these features - my spec is
coming in at 1700-odd quid which is already too expensive, but I like the
overall benefits of no CW tank (waste of space in my house due to attic
conversion), mains pressure drinkable HW and I can get the solar coil
option for future expansion as it costs very little extra on the tank.

Not to mention electrical backup for when the boiler dies (they always do,
always at the worst time!). I'm getting 3 x 3kW immersion heaters in mine,
which don't cost a lot, provided you stay away from their fancy built in
controller (mine will have a contactor driven off a very simple timeswitch
which will suffice in an emergency)

BTW, did you really need lead free solder? (Was it on the potable parts)
I'm using 60/40 on the heating and lead free only where I need to.

I ran out and it was all I could get. After discovering a couple of leaks
in 'awkward' joints and having to re-do them I went back to leaded.


Always the way... I tried to solder a PCB with slivers cut off a stick of
plumber's metal when I was a lad, for similar reasons. That didn't work
very well (oddly enough!).

Cheers

Tim

On Sat, 18 Oct 2008 13:52:45 +0100, Tim S wrote:

I'm not committed on paper yet. So, in the spirit of open-mindedness:

Question: I thought one couldn't work DIY on hot pressurised plumbing - and
that it needed to be checked every year? Did I get that wrong (that would
be a deciding factor for me)?

Yes, you got that wrong. Unvented (sealed) *hot water* systems are
controlled by building regulations.

The other thing is that, DPS do do heatbanks for sealed systems, but
effectively you end up with lots of heat exchangers (assuming you run
the rads pressurised too) so it seemed to make things more complicated
with at least two different circuits to fill plus the cylinder itself
which can't be pressurised (IIRC they do one with a little integral
header tank and float valve, so we'll assume that should sort itself
out).

The DPS unit is just a box (some are even box-shaped). Hes it's got 2 heat
exchangers in it (one a coil in the cylinder/box-shaped-store, one plate
heat exchanger) but it Just Works. (Except when it doesn't of course :-))

Not sure how much it bungs the cost up to add these features - my spec
is coming in at 1700-odd quid which is already too expensive, but I like
the overall benefits of no CW tank (waste of space in my house due to
attic conversion), mains pressure drinkable HW and I can get the solar
coil option for future expansion as it costs very little extra on the
tank.

I wouldn't bother with a solar coil option[1], any more than I'd consider a
windmill except as decoration (our latest megaTescos has got an array of
them on the roof of its petrol station: they look almost as good as the
one on Teletubbies :-))

Not to mention electrical backup for when the boiler dies (they always
do, always at the worst time!). I'm getting 3 x 3kW immersion heaters in
mine, which don't cost a lot, provided you stay away from their fancy
built in controller (mine will have a contactor driven off a very simple
timeswitch which will suffice in an emergency)

Yebbut when the boiler goes down you'll also be running a stack of
electric space heaters around the place so demanding an extra 9kW for DHW
may not be the cleverest move.


[1] apart from the appalling economics and ecologics of solar DHW in these
climes, if you did still have money to burn in putting one in you could at
least do it properly with a decent-sized store of its own rather than
sharing a tiddly bit of space at the bottom of a regular store.

--
YAPH http://yaph.co.uk

Blamestorming
Sitting around in a group, discussing why a deadline was missed
or a project failed, and who was responsible.

YAPH coughed up some electrons that declared:

snip

Yes, you got that wrong. Unvented (sealed) *hot water* systems are
controlled by building regulations.

OK - Thanks... I assumed it was solely to do with having a pressurised
system (and the possibility of things going bang).

snip

The DPS unit is just a box (some are even box-shaped). Hes it's got 2 heat
exchangers in it (one a coil in the cylinder/box-shaped-store, one plate
heat exchanger) but it Just Works. (Except when it doesn't of course :-))

The one I was looking at has no coils and one plate exchanger. It's so
simple, you could pretty much make one from a very very big normal copper
cylinder. If I could figure a way to add extra bosses, heater flanges and
insulation to a simple copper cylinder I would. But it's not easy to do it
properly (especially the insulation). Not forgetting of course that the DPS
price includes all the pumps, mixer valves and heaters and stats.

I wouldn't bother with a solar coil option[1], any more than I'd consider
a windmill except as decoration (our latest megaTescos has got an array of
them on the roof of its petrol station: they look almost as good as the
one on Teletubbies :-))

Well, the coil is cheap as the unit is already there. I think it's a bit
unfair to compare windmills to solar panels. Looking at it, I don't think
the panels are worth it yet on payback grounds - but with the new vacuum
tubes becoming cheaper and better over time, and gas becoming more
expensive, I can see a time, possibly in the next few years that it might
be a genuinely good idea.

snip
Yebbut when the boiler goes down you'll also be running a stack of
electric space heaters around the place so demanding an extra 9kW for DHW
may not be the cleverest move.

The idea is just run a couple of rads off the system (as far as 9kW goes),
but they can be any couple of rads as the day progresses. It's one of those
things that's going to be a rare occurrance, but the cost of doing this is
next to nothing. I'll have a couple of fireplaces open anyway, so two areas
will be heated by wood.


[1] apart from the appalling economics and ecologics of solar DHW in these
climes, if you did still have money to burn in putting one in you could at
least do it properly with a decent-sized store of its own rather than
sharing a tiddly bit of space at the bottom of a regular store.


That's a fair point. I've just thought it through... Here's what I think:

In summer, we don't use the rads (ha!) so we attempt to supply HW from
solar, so we restrict the operation of the boiler and avoid daytime burns.
We run the boiler overnight just to bring the system up to capacity.

In other times, solar may contribute, but we clearly need boiler input
because either solar input is low or demand is high. This is the hardest
case.

Now, I don't have room for an extra cylinder just for solar. The answer
might be to give more of the cylinder over to solar, which would mean
different takeoff points on the tank for the primary circuit.

It's an interesting idea. DPS are quite flexible and local to me (well,
Epsom isn't that far from Kent). Might be interesting to consider having
them put in an extra primary connection higher up (no coils, so it's just
bosses).

Would allow for some flexibility. I can see how it might possibly be an
advantage to alter the dynamics of the unit if we ever did have decent
solar input. I'll have to think it through some more.

If there was a provable scenario where altering the flow dynamics were a
good idea, one could add a 3 way valve and a computer later.

I think solar is "watch this space" but I am quite optimistic it will become
a sensible option in 5, maybe 10 years. I'm not known round here for being
a greenie-fad monster(!)

Cheers

Tim

Tim S coughed up some electrons that declared:


Might be interesting to consider having
them put in an extra primary connection higher up (no coils, so it's just
bosses).

I should have said "no coils on the boiler side".

In article ,
Tim S wrote:
Dave Plowman (News) coughed up some electrons that declared:

In article ,
Tim S wrote:
Thanks for raising it - it's good to check these things.

snippety snoop

It is indeed. However, although I was against a sealed system I'm now
converted. Can't think of any advantage of open - apart from adding
inhibitor etc - but this is really not much more difficult using a
concentrate via a rad bleed. And it does make filling so much easier -
no airlocks. Of course the 200 includes an expansion vessel - so no
additional expense there apart from some pipework mods.

Hi Dave,

I'm not committed on paper yet. So, in the spirit of open-mindedness:

Question: I thought one couldn't work DIY on hot pressurised plumbing -
and that it needed to be checked every year? Did I get that wrong (that
would be a deciding factor for me)?

That only applies to the secondary hot water circuit - not the primary.
But I'm not sure if it applies to every make of pressurised water heating
circuit.

The other thing is that, DPS do do heatbanks for sealed systems, but
effectively you end up with lots of heat exchangers (assuming you run
the rads pressurised too) so it seemed to make things more complicated
with at least two different circuits to fill plus the cylinder itself
which can't be pressurised (IIRC they do one with a little integral
header tank and float valve, so we'll assume that should sort itself
out).

No idea, I'm afraid.

Not sure how much it bungs the cost up to add these features - my spec is
coming in at 1700-odd quid which is already too expensive, but I like the
overall benefits of no CW tank (waste of space in my house due to attic
conversion), mains pressure drinkable HW and I can get the solar coil
option for future expansion as it costs very little extra on the tank.

That's separate from a pressurized primary. I've kept my header tank for
the hot water system - for all the obvious reasons. The space it occupies
wouldn't be much use for anything else.

Not to mention electrical backup for when the boiler dies (they always
do, always at the worst time!). I'm getting 3 x 3kW immersion heaters in
mine, which don't cost a lot, provided you stay away from their fancy
built in controller (mine will have a contactor driven off a very simple
timeswitch which will suffice in an emergency)

BTW, did you really need lead free solder? (Was it on the potable
parts) I'm using 60/40 on the heating and lead free only where I need
to.

I ran out and it was all I could get. After discovering a couple of
leaks in 'awkward' joints and having to re-do them I went back to
leaded.


Always the way... I tried to solder a PCB with slivers cut off a stick
of plumber's metal when I was a lad, for similar reasons. That didn't
work very well (oddly enough!).

I've not investigated it, but it just didn't flow round the back of an
awkward joint as I'd expect with leaded. The part you could see was fine.
And I've done probably hundreds of similar leaded end feed joints without
probs.

But I won't use lead free for electronics either. Too many reports of
problems.

--
*Born free - taxed to death *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) coughed up some electrons that declared:


I've not investigated it, but it just didn't flow round the back of an
awkward joint as I'd expect with leaded. The part you could see was fine.
And I've done probably hundreds of similar leaded end feed joints without
probs.

But I won't use lead free for electronics either. Too many reports of
problems.


The company I currently work for still use leaded as they do vehicle
electronics and that's exempted from the ROHS rules on solder as is medical
and avionics. Says a lot doesn't it!

I really fail to see the point in banning leaded solder for potable fittings
as the surface area of solder exposed to the water is bugger all.

I need to practise with some lead free joints. But if they are as difficult
as this to get reliable, I know what I'll be doing.

Cheers

Tim

In article ,
"Dave Plowman (News)" writes:
In article ,
Tim S wrote:
Dave Plowman (News) coughed up some electrons that declared:

In article ,
Tim S wrote:
BTW, did you really need lead free solder? (Was it on the potable
parts) I'm using 60/40 on the heating and lead free only where I need
to.

I ran out and it was all I could get. After discovering a couple of
leaks in 'awkward' joints and having to re-do them I went back to
leaded.


Always the way... I tried to solder a PCB with slivers cut off a stick
of plumber's metal when I was a lad, for similar reasons. That didn't
work very well (oddly enough!).

I've not investigated it, but it just didn't flow round the back of an
awkward joint as I'd expect with leaded. The part you could see was fine.
And I've done probably hundreds of similar leaded end feed joints without
probs.

I've done quite a lot of lead-free, but the vast majority leaded.
I can't really claim I notice much difference, except the lead-free
seems more fluid, and sets with a brighter mirror finish.

But I won't use lead free for electronics either. Too many reports of
problems.

Most of my component stocks are leaded, and likely will be for ever.
I solder components at 800F anyway, and always have done even with
leaded. It enables a quick soldering and exit.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
I've not investigated it, but it just didn't flow round the back of an
awkward joint as I'd expect with leaded. The part you could see was
fine. And I've done probably hundreds of similar leaded end feed
joints without probs.

I've done quite a lot of lead-free, but the vast majority leaded.
I can't really claim I notice much difference, except the lead-free
seems more fluid, and sets with a brighter mirror finish.

That's exactly the reverse of what I found. Although there could of course
have been another reason. The joints that weren't made properly were ones
where it wasn't possible to access all round, and although the solder
flowed easily at the top and sides it didn't get to underneath. The pipe
and fittings were new and spotless. I was using an active flux - the same
stuff I was using for leaded.

But I won't use lead free for electronics either. Too many reports of
problems.

Most of my component stocks are leaded, and likely will be for ever.
I solder components at 800F anyway, and always have done even with
leaded. It enables a quick soldering and exit.

Crikey. That is hot. I use about 350C.

--
*I don't have a solution, but I admire your problem. *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 18 Oct 2008 17:37:42 +0100, Tim S wrote:


The one I was looking at has no coils and one plate exchanger.

I thought you were looking at their Pandora units, but I think you're
talking about their GX(?) models?

It's so
simple, you could pretty much make one from a very very big normal copper
cylinder.

BTDTGTTS - see DIY heat bank in wiki.diyfaq.org.uk


I think it's a bit unfair to compare windmills to solar panels.

They both have their places, but they tend not to be urban houses with
mains gas and electricity supplies.


Yebbut when the boiler goes down you'll also be running a stack of
electric space heaters around the place so demanding an extra 9kW for
DHW may not be the cleverest move.

The idea is just run a couple of rads off the system (as far as 9kW
goes), but they can be any couple of rads as the day progresses. It's
one of those things that's going to be a rare occurrance, but the cost
of doing this is next to nothing. I'll have a couple of fireplaces open
anyway, so two areas will be heated by wood.

Ah, OK you're running the CH off the heat bank too - didn't realise that.



Now, I don't have room for an extra cylinder just for solar. The answer
might be to give more of the cylinder over to solar, which would mean
different takeoff points on the tank for the primary circuit.

It's an interesting idea. DPS are quite flexible and local to me (well,
Epsom isn't that far from Kent). Might be interesting to consider having
them put in an extra primary connection higher up (no coils, so it's
just bosses).

What about additives? Solar systems generally need antifreeze which means
you'd hav eto dose your entire primary (boiler, rads and heat bank) with
it too.


I think solar is "watch this space" but I am quite optimistic it will
become a sensible option in 5, maybe 10 years. I'm not known round here
for being a greenie-fad monster(!)

They seem to have been just 5-years around the corner for the last 2 or 3
decades. Heat pumps look to be a more realistic prospect. Google for
McKay's "renewables without the hot air" or something like that for some
clear thinking on the subject.

--
YAPH http://yaph.co.uk

Seagull Management
Management technique characterised by flying in, making a lot of noise,
crapping on everything, and then leaving.

On Sat, 18 Oct 2008 21:00:53 +0100, Tim S wrote:

I need to practise with some lead free joints. But if they are as
difficult as this to get reliable, I know what I'll be doing.

I generally use solder-ring fittings which (I assume) have lead free
solder, and have no problems. Possibly it flows less well or something: I
tend to wiggle the joint once it's started flowing until I can clearly see
a ring of solder to make sure it's wetted all the way around. Maybe it
wasn't like that on the old leaded joints but it's so long since I used
them I couldn't be sure.

There are brands of flux described as 'lead-free'. Since flux obviously
doesn't ever contain lead I assume they're designed to work better with
lead-free solders. I'm currently using La-Co, before that I used the
Fernox stuff. It all seems OK though.

--
YAPH http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

In article ,
YAPH wrote:
There are brands of flux described as 'lead-free'. Since flux obviously
doesn't ever contain lead I assume they're designed to work better with
lead-free solders. I'm currently using La-Co, before that I used the
Fernox stuff. It all seems OK though.

That's what I wondered after my failures. But looking at fluxes in the PM
non seemed to mention suitability or not for either.

--
*What do little birdies see when they get knocked unconscious? *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
"Dave Plowman (News)" writes:
In article ,
Andrew Gabriel wrote:
Most of my component stocks are leaded, and likely will be for ever.
I solder components at 800F anyway, and always have done even with
leaded. It enables a quick soldering and exit.

Crikey. That is hot. I use about 350C.

700F (370C) are the more common bits for my iron, at least in the
days of leaded solder, although 800F was always available as an
option. It may be 800F is the default now lead free is more common.
800F bits don't last as long (the iron plating fails faster).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Tim S" wrote in message
...
Dave Plowman (News) coughed up some electrons that declared:

In article ,
GB wrote:
Dave Starling wrote:
On Oct 16, 8:54 pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors.
They're at the lower end of the price range for decent boilers (cf
Vaillant) and W-B don't have any reliability issues with their
boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.


Am I right in thinking that Vaillant is still the make of choice if
price no object (within reason)?

What about Viessmann? I've recently installed mine - a system boiler -
and
it's beautifully made. They do a similar combi.


I'm glad to hear that as I've asked the local gas fitter to quote for a
Vitodens 100 Compact (he's also on the Viessmann list of trained
installers).

He did spend some time trying to sell me a weather compensation system and
a
pressurised system, though once I'd knocked it into him that I was
specifying both a vented and a braindead but efficient and reliable boiler
to drive a heatbank, he gracefully gave up and recommended the 100 which
concurred with what I already thought.

Wait to see what his quote looks like...

Look at Broag:
http://www.avantaplus.co.uk

"Tim S" wrote in message
...
Dave Plowman (News) coughed up some electrons that declared:


Heh - I'm working the other way around, mains pressure hot water and
vented rads/boiler primary.
[snip]

I'd check with Viessmann before going down this route. I've a feeling it
will invalidate the warranty. But can't be arsed digging out the
installation book at this time of night.


I'll be reading the installation manual too - but why do you think that
Dave?

I'm going for a boiler designed for open vented use and the mains pressure
water is generated in a heat exchanger by the heatbank - it's not a combi
boiler, if that's what you're thinking?

He doesn't understand so don't make an issue with him. Try the open vented
Broag 18v.

"GB" wrote in message
...
Dave Starling wrote:
On Oct 16, 8:54 pm, YAPH wrote:
Personally I fit Worcester-Bosch, mostly Greenstar 24i Juniors.
They're at the lower end of the price range for decent boilers (cf
Vaillant) and W-B don't have any reliability issues with their
boilers (not that I
Thats the boiler which has the vertical heat exchanger that is pulled
out to service it? Its also the same one which the baffles 'weld'
themselves into the heat exchanger so its impossible to ever clean
inside it!
Only done one of these 3 years ago and apparently its now making
horrible noises and will no doubt have to replace at somepoint soon.


Am I right in thinking that Vaillant is still the make of choice if price
no object (within reason)?

No. ATAG, Atmos, Broag, MAN are all better boilers. The Viessman 100 range
is crap (made for the UK market) The 200 and 300 are better.

"YAPH" wrote in message
...
On Sat, 18 Oct 2008 13:52:45 +0100, Tim S wrote:

I'm not committed on paper yet. So, in the
spirit of open-mindedness:

Question: I thought one couldn't work DIY
on hot pressurised plumbing - and
that it needed to be checked every year?
Did I get that wrong (that would
be a deciding factor for me)?

Yes, you got that wrong. Unvented (sealed)
*hot water* systems are
controlled by building regulations.

Sealed (pressurised) thermal stores do not come under G3 and can be DIYed.
The cylinder has no complex pressure controls. Effectively it is just a
large pipe in the sealed CH system. Best have a 3 to 3.5 bar pressure relief
valve on the boiler and cylinder. Backup if one goes. They tend to have that
anyway.

look at:
http://www.advanceappliances.co.uk/index.html

[1] apart from the appalling economics
and ecologics of solar DHW in these
climes,

DIYing it makes economic sense.

In article ,
Doctor Drivel wrote:
Look at Broag:
http://www.avantaplus.co.uk

Oh look. He's got yet another favourite. The catalogues must be red hot.

--
*If at first you don't succeed, try management *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
Look at Broag:
http://www.avantaplus.co.uk

Oh

Eff off you are an idiotic Jocko plant.

In article ,
Doctor Drivel wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
Look at Broag:
http://www.avantaplus.co.uk

Oh

Eff off you are an idiotic Jocko plant.

Wot - no pot? Are you smoking it instead of your usual alcohol?

--
*What boots up must come down *

Dave Plowman London SW
To e-mail, change noise into sound.