OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

On Fri, 11 Mar 2011 01:10:53 -0800, sm_jamieson wrote:

OK, this changes from time to time I guess. I may be getting a new combi
boiler , about 30kW. Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)

What's ridiculous about a mere 10 years? The only crop of the recent
generation of boilers that I wouldn't expect to last that long are
Ideal's horribly unreliable and expensive to repair POSes. (I've taken
one out recently.)

The Worcester-Bosch Greenstars I've been putting in over the last 5 years
or so seem to be plodding along OK. What'll be interesting is to see
which designs are making it to the 20 year mark.

--
John Stumbles

John Stumbles wrote:
On Fri, 11 Mar 2011 01:10:53 -0800, sm_jamieson wrote:

OK, this changes from time to time I guess. I may be getting a new
combi boiler , about 30kW. Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)

What's ridiculous about a mere 10 years? The only crop of the recent
generation of boilers that I wouldn't expect to last that long are
Ideal's horribly unreliable and expensive to repair POSes. (I've taken
one out recently.)

The Worcester-Bosch Greenstars I've been putting in over the last 5
years or so seem to be plodding along OK.

That's good news. I had a WB Greenstar 30 CDi put in three years ago. No
problems so far, touch wood (apart from condensate pipe freezing this
winter).

Mind you, the Baxi conventional boiler that the Greenstar replaced was 31
years old and still going strong when replaced...

--
Triff

Triffid wrote:

Mind you, the Baxi conventional boiler that the Greenstar replaced was
31 years old and still going strong when replaced...


Now that's the comparison I'd like to see. The total running costs of a
cast iron block against three combis over the same period.

In article ,
Andy Cap wrote:
Mind you, the Baxi conventional boiler that the Greenstar replaced was
31 years old and still going strong when replaced...


Now that's the comparison I'd like to see. The total running costs of a
cast iron block against three combis over the same period.

Not like for like. Compare it to a non combi condensing boiler.

--
*Age is a very high price to pay for maturity.

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

Dave Plowman (News) wrote:

Now that's the comparison I'd like to see. The total running costs of a
cast iron block against three combis over the same period.

Not like for like. Compare it to a non combi condensing boiler.

That's fine and will be my choice, but it's not what most people are
sold and the combis are sold on the grounds of savings and I'd like to
see an honest comparison.

In article ,
Andy Cap wrote:
Now that's the comparison I'd like to see. The total running costs of
a cast iron block against three combis over the same period.

Not like for like. Compare it to a non combi condensing boiler.

That's fine and will be my choice, but it's not what most people are
sold and the combis are sold on the grounds of savings and I'd like to
see an honest comparison.

Would actually cost more if you have an existing storage system. New
install different.

--
*What happens when none of your bees wax? *

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

On 11/03/2011 09:10, sm_jamieson wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

I had an Atmos HE32 (Daventry) installed approx 2yrs ago, excellent
boiler and no problems so far. Viesman (Telford) also has a very good
reputation.
Don

Andy Cap wrote:
Dave Plowman (News) wrote:

Now that's the comparison I'd like to see. The total running costs
of a cast iron block against three combis over the same period.

Not like for like. Compare it to a non combi condensing boiler.

That's fine and will be my choice, but it's not what most people are
sold and the combis are sold on the grounds of savings and I'd like to
see an honest comparison.

Our gas consumption has dropped significantly since replacing the 31 year
old Baxi conventional with the WB Greenstar condensing combi.

Clearly, only heating the hot water that you actually need, rather than
heating a whole tankful of water 'just in case' you might need it, is a
considerable saving.

We have also found that the radiators heat up far more rapidly when the
heating kicks in first thing in the morning. This is because, of course, all
the efforts of the boiler are put into heating the radiators, rather than
also heating up a large tankful of hot water as well.

It's not all positive, of course, it takes a bit longer to fill the bath
(although the shower, fed straight from the boiler, is perfect). There will
be no stored hot water if the boiler packs up.

I was 'nervous' about switching from a conventional system to a combi - but
actually have no regrets whatsoever now we've done it.

--
Triff.

On Mar 11, 9:10*am, sm_jamieson wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a
conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. You will still
have to have a condensing boiler. It will cost you more but there
will be far less trouble and expense with repairs and spare parts.
This also means you can install a solar hot water roof panel which you
can't with a combi. Also your bath will fill quickly.

On Mar 11, 2:56*pm, harry wrote:
On Mar 11, 9:10*am, sm_jamieson wrote:

OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a
conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. *You will still
have to have a condensing boiler. *It will cost you more but there
will be far less trouble and expense with repairs and spare parts.
This also means you can install a solar hot water roof panel which you
can't with a combi. *Also your bath will fill quickly.

And do you have a noisy pump to get a power shower ?
And what do you do when your hot water runs out ?
Simon.

In article
,
sm_jamieson wrote:
Don't bother with a combi. They are ****e of the devil. Put in a
conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. You will still
have to have a condensing boiler. It will cost you more but there
will be far less trouble and expense with repairs and spare parts.
This also means you can install a solar hot water roof panel which you
can't with a combi. Also your bath will fill quickly.

And do you have a noisy pump to get a power shower ?

That would depend entirely on the head from the header tank. In my case
the shower is more than OK without a pump.

And what do you do when your hot water runs out ?

Mine will give an adequately warm shower constantly, even if you start
with no hot water left. Uses a fast recovery cylinder. But this doesn't
matter much in practice - only discovered it after coming back from
holiday.

--
*He who laughs last, thinks slowest.

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

harry wrote:
On Mar 11, 9:10 am, sm_jamieson wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec ?
I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a
conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. You will still
have to have a condensing boiler. It will cost you more but there
will be far less trouble and expense with repairs and spare parts.
This also means you can install a solar hot water roof panel which you
can't with a combi. Also your bath will fill quickly.

But...

Every day you are paying out good money to heat up a whole tank of hot
water - that you may never use. Your boiler, first thing in the morning, is
having to work overtime heating both the radiators *and* the tankful of
water that you will probably only use a fraction of.

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern condensing
combis are a dramatic improvement on the earlier efforts.

We have had the combi for three years now and have no regrets. I was able to
remove all the plumbing and tanks from the loft. Got rid of the noisy
power-shower, got rid of the hot water tank, ripped out the airing cupboard
from the bathroom and replaced it with an offset-quadrant walk-in shower,
and now enjoy significantly lower fuel bills, a better and quieter shower,
and faster heating radiators.

It *does* take a bit longer to fill the bath - but I opted for a larger than
necessary boiler with a high flow-through of hot water - and the extra time
is really not an issue, particularly when my wife and I shower every day and
only usually have a bath when we want a 'warm-up' soak!

--
Triff

In article ,
Triffid wrote:
Every day you are paying out good money to heat up a whole tank of hot
water - that you may never use. Your boiler, first thing in the morning,
is having to work overtime heating both the radiators *and* the tankful
of water that you will probably only use a fraction of.

Switch the system on earlier, then. And have a well insulated storage
cylinder.

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern
condensing combis are a dramatic improvement on the earlier efforts.

Reliability is more of an issue to me.

--
*The man who fell into an upholstery machine is fully recovered*

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

On Fri, 11 Mar 2011 15:42:07 -0000, Triffid wrote:

Every day you are paying out good money to heat up a whole tank of hot
water - that you may never use.

Not if it's well insulated. You've only got to supply enough heat to
replace that lost by using hot water or through convection/conduction.

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern
condensing combis are a dramatic improvement on the earlier efforts.

I'm all for having a condensing boiler, but a combi doesn't suit our
situation. We have *three* showers, and it's not unusual for two (if not
all three) to be in use at the same time. Our large hot water cylinder
can cope with that; I don't think a combi would.

It also happens that the cylinder is quite near the bathrooms, so the
showers run hot almost immediately. There's a long pipe run from the
boiler, so with a combi we'd be waiting ages and wasting water at the same
time.

We have had the combi for three years now and have no regrets. I was
able to remove all the plumbing and tanks from the loft.

We don't have any tanks in the loft either - it's all directly off the
mains (so good pressure for showers without needing a pump).

So I agree about not having open tanks, not requiring pumps, and using a
modern efficient condensing boiler. But none of that necessarily implies
a combi: we get all those advantages from our System Boiler and a large,
well insulated, hot water cylinder.

Richard.
http://www.rtrussell.co.uk/

John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec
? I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. You will still
have to have a condensing boiler. It will cost you more but there
will be far less trouble and expense with repairs and spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer a
small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all else
evil" and their inverse, is they ignore the real world. There are
plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my household
because there is only one bathroom and just the two of us. If we had an
en-suite and wanted to shower at the same time, a conventional storage
system would probably be a better bet.

--
Kev

On Mar 11, 5:55*pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, *wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that spec
? I.e. one that has the vaguest hope of lasting 10 years (I know its
ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank (well
lagged). There's such a thing as too much technology. *You will still
have to have a condensing boiler. *It will cost you more but there
will be far less trouble and expense with repairs and spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer a
small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. *Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all else
evil" and their inverse, is they ignore the real world. There are
plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my household
because there is only one bathroom and just the two of us. If we had an
en-suite and wanted to shower at the same time, a conventional storage
system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with semiskilled
labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. Minimum technology to
achieve requirements.

On 11/03/2011 14:46, Triffid wrote:
Andy Cap wrote:
Dave Plowman (News) wrote:

Now that's the comparison I'd like to see. The total running costs
of a cast iron block against three combis over the same period.

Not like for like. Compare it to a non combi condensing boiler.

That's fine and will be my choice, but it's not what most people are
sold and the combis are sold on the grounds of savings and I'd like to
see an honest comparison.

Our gas consumption has dropped significantly since replacing the 31
year old Baxi conventional with the WB Greenstar condensing combi.

snip

I'm not at all surprised that your new boiler is more efficient than the
old one. But I think that is because it is a modern condensing one, not
because it is a combi.

You don't need to heat a full tank of water every day. If you've used
water, you need to heat it. That's the same for both types. A tank of
hot water stays hot for _days_ given a foam jacket. There's barely
enough heat to keep the airing cupboard warm.

.... and when my old boiler dies I'll turn on the immersion heater until
I can get a new one fitted. What will you do?

You do have a point on the shower pump though.

Andy

harry wrote:
On Mar 11, 5:55 pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that
spec ? I.e. one that has the vaguest hope of lasting 10 years (I
know its ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank
(well lagged). There's such a thing as too much technology. You
will still have to have a condensing boiler. It will cost you more
but there will be far less trouble and expense with repairs and
spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer
a small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all
else evil" and their inverse, is they ignore the real world. There
are plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my
household because there is only one bathroom and just the two of us.
If we had an en-suite and wanted to shower at the same time, a
conventional storage system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with semiskilled
labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. Minimum technology to
achieve requirements.

Well, I hear what you say, but the significant advantage for us was being
able to get rid of the airing cupboard in the bathroom and replace it with a
walk-in shower. Because the new shower has clear glass doors it has made the
bathroom appear much larger as well.

Having instant hot water always on tap is also a bonus.

I agree with the need to keep things simple - and our plumbing system is now
a lot simpler than it was when it had two header tanks in the loft and a hot
water cylinder in the airing cupboard. (I got £75 scrap for the copper tank
and redundant pipework when the job was done)

There is now no float valves to stick or go wrong in the loft, no chance of
any leaks or bursts in the loft, no motorised valves in the system to stick
or go wrong.

I couldn't believe the amount of gunge there was in the bottom of the cold
water tanks in the loft either!

--
Triff

In article , Triffid
writes
harry wrote:
On Mar 11, 5:55 pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that
spec ? I.e. one that has the vaguest hope of lasting 10 years (I
know its ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank
(well lagged). There's such a thing as too much technology. You
will still have to have a condensing boiler. It will cost you more
but there will be far less trouble and expense with repairs and
spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer
a small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all
else evil" and their inverse, is they ignore the real world. There
are plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my
household because there is only one bathroom and just the two of us.
If we had an en-suite and wanted to shower at the same time, a
conventional storage system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with semiskilled
labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. Minimum technology to
achieve requirements.

Well, I hear what you say, but the significant advantage for us was being
able to get rid of the airing cupboard in the bathroom and replace it with a
walk-in shower. Because the new shower has clear glass doors it has made the
bathroom appear much larger as well.

Having instant hot water always on tap is also a bonus.

I agree with the need to keep things simple - and our plumbing system is now
a lot simpler than it was when it had two header tanks in the loft and a hot
water cylinder in the airing cupboard. (I got £75 scrap for the copper tank
and redundant pipework when the job was done)

There is now no float valves to stick or go wrong in the loft, no chance of
any leaks or bursts in the loft, no motorised valves in the system to stick
or go wrong.

I couldn't believe the amount of gunge there was in the bottom of the cold
water tanks in the loft either!

Lucky you - although the Combi at the Scout Hut provides adequate heat
to the radiators, it fails to give anything other than tepid water out
of the taps event when it is turned up to max and the taps down to the
lowest flow that triggers the boiler.
--
John Alexander,

Remove NOSPAM if replying by e-mail

On Mar 11, 9:34*pm, "Triffid" wrote:

There is now no float valves to stick or go wrong in the loft, no chance of
any leaks or bursts in the loft, no motorised valves in the system to stick
or go wrong.

If you are going to draw comparisons you need to be thorough on both
sides. You have omitted the potential issues you may face with the
secondary heat exchanger and diverter valve that the combi introduces.
Also, the lack of any backup hot water availability should the boiler
breakdown.

If I had the choice of fixing/replacing a motorised valve in an airing
cupboard or a diverter valve inside a boiler I know which I'd
prefer... ;-)

Besides which, you really ought to be comparing against a modern
unvented cylinder as these address most of your concerns about
'conventional' systems - heat loss, flow rate, pressure, float valves
etc.

Mathew

On Mar 11, 10:29*pm, John wrote:
In article , Triffid
writes

harry wrote:
On Mar 11, 5:55 pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that
spec ? I.e. one that has the vaguest hope of lasting 10 years (I
know its ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank
(well lagged). There's such a thing as too much technology. You
will still have to have a condensing boiler. It will cost you more
but there will be far less trouble and expense with repairs and
spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer
a small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all
else evil" and their inverse, is they ignore the real world. There
are plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my
household because there is only one bathroom and just the two of us.
If we had an en-suite and wanted to shower at the same time, a
conventional storage system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with semiskilled
labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. * Minimum technology to
achieve requirements.

Well, I hear what you say, but the significant advantage for us was being
able to get rid of the airing cupboard in the bathroom and replace it with a
walk-in shower. Because the new shower has clear glass doors it has made the
bathroom appear much larger as well.

Having instant hot water always on tap is also a bonus.

I agree with the need to keep things simple - and our plumbing system is now
a lot simpler than it was when it had two header tanks in the loft and a hot
water cylinder in the airing cupboard. (I got �75 scrap for the copper tank
and redundant pipework when the job was done)

There is now no float valves to stick or go wrong in the loft, no chance of
any leaks or bursts in the loft, no motorised valves in the system to stick
or go wrong.

I couldn't believe the amount of gunge there was in the bottom of the cold
water tanks in the loft either!

Lucky you - although the Combi at the Scout Hut provides adequate heat
to the radiators, it fails to give anything other than tepid water out
of the taps event when it is turned up to max and the taps down to the
lowest flow that triggers the boiler.
--
Hmm. Mine gives a power shower performance with water as hot as you
like.
Simon.

On Mar 11, 7:22*pm, harry wrote:

Keep It Stupid Simple is always the way to go. *

Glad to see you're living up to it, simpleton.

On Mar 11, 3:42*pm, "Triffid" wrote:

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern condensing
combis are a dramatic improvement on the earlier efforts.

It's not condensing that made combis work, it was building them of
adequate power. This has been usual practice for the last 15+ years
and competently specified combis, built by competent makers (i.e. no
Ravenheats) have worked well ever since. The old problematic ones were
just too small.

If you want a multi-fuel system with solar or solid input too, then
you do still need some sort of thermal store. If you're designing a
purely gas system, then combis are the way to go.

On Mar 11, 9:34*pm, "Triffid" wrote:
harry wrote:
On Mar 11, 5:55 pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that
spec ? I.e. one that has the vaguest hope of lasting 10 years (I
know its ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank
(well lagged). There's such a thing as too much technology. You
will still have to have a condensing boiler. It will cost you more
but there will be far less trouble and expense with repairs and
spare parts.

Huh?

What is the difference between a system boiler, and a combi? Answer
a small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel which
you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all
else evil" and their inverse, is they ignore the real world. There
are plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my
household because there is only one bathroom and just the two of us.
If we had an en-suite and wanted to shower at the same time, a
conventional storage system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with semiskilled
labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. * Minimum technology to
achieve requirements.

Well, I hear what you say, but the significant advantage for us was being
able to get rid of the airing cupboard in the bathroom and replace it with a
walk-in shower. Because the new shower has clear glass doors it has made the
bathroom appear much larger as well.

Having instant hot water always on tap is also a bonus.

I agree with the need to keep things simple - and our plumbing system is now
a lot simpler than it was when it had two header tanks in the loft and a hot
water cylinder in the airing cupboard. (I got �75 scrap for the copper tank
and redundant pipework when the job was done)

There is now no float valves to stick or go wrong in the loft, no chance of
any leaks or bursts in the loft, no motorised valves in the system to stick
or go wrong.

I couldn't believe the amount of gunge there was in the bottom of the cold
water tanks in the loft either!

--
Triff- Hide quoted text -

- Show quoted text -

All the items you mention still exist in more complex unreliable form
inside your combi boiler. The crap in your tanks was in the incoming
water. Goes straight into the boiler and helps bugger it up. The bits
you had before were many years old and still had usefull life in them.
Your combi will start to go wrong in only a few years if you're lucky
& henceforth you will have nothing but trouble and expense.
It is filled with cheap nasty crap designed to see it through the
guarantee period & that's all.

On Mar 12, 12:48*am, Andy Dingley wrote:
On Mar 11, 3:42*pm, "Triffid" wrote:

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern condensing
combis are a dramatic improvement on the earlier efforts.

It's not condensing that made combis work, it was building them of
adequate power. This has been usual practice for the last 15+ years
and competently specified combis, built by competent makers (i.e. no
Ravenheats) have worked well ever since. The old problematic ones were
just too small.

If you want a multi-fuel system with solar or solid input too, then
you do still need some sort of thermal store. If you're designing a
purely gas system, then combis are the way to go.

In only a few years gas will be too expensive for heating. (Libya is
the start) The is no such thing as purely gas,we all need electricity
in the house. This leads to premium payments for the first bit/meter
rental for both gas and electric.
So therefore gas is not the way to go at all. Zero gas and zero gas
meter rentals is the way to go.
Heat pumps and electricity are the way to. Zero maintenance and
little to go wrong. Run off PV panels on the roof if you like.
Don't be a lemming, be ahead of the proles.

The age of gas is finished.

On Mar 12, 12:44*am, Andy Dingley wrote:
On Mar 11, 7:22*pm, harry wrote:

Keep It Stupid Simple is always the way to go. *

Glad to see you're living up to it, simpleton.

Well ahead of the half wits such as yourself.

On Sat, 12 Mar 2011 00:40:43 -0800, harry wrote:

Heat pumps and electricity are the way to. Zero maintenance and little
to go wrong. Run off PV panels on the roof if you like. Don't be a
lemming, be ahead of the proles.

Oh dear. So, having dug up your garden or drilled boreholes for ground
source so you can use your heat pump in the cold bits of the winter, and
having ripped out all your radiators and installed UFH or fanned rads to
work with low flow temperatures to get a COP of circa 4 for a well-
designed and correctly installed system, and having insulated your house
to the gunwhales so you can manage with about 10kW heat input when it's
below freezing outside, you're going to get the c. 2kW electrical power
the heat pump requires to operate from your PV on the roof? On a grey
winters day? Or night?

--
John Stumbles

Eagles may soar, but weasels don't get sucked into jet engines.

On Fri, 11 Mar 2011 11:22:30 -0800, harry wrote:

Absolutely stupid removing an existing DHW cylinder/header tank(s) just
to put in a combi.

In small houses (what many of us proles have to live in, even if you live
ina a mansion) the space used by a HW cylinder, and tanks in the roof, is
valuable enough to make a combi attractive.

Also if the existing system has gravity circulation on the DHW side then
the extra cost of converting to fully-pumped can swing it in favour of a
combi when the boiler's being replaced. (Depends on pipework layout, and,
of course, whether a combi is suitable for the water demands of the
household.)

Keep It Stupid Simple is always the way to go. Minimum technology to
achieve requirements.

Some on this ng seem intent on Simply Keeping It Stupid.


--
John Stumbles

Procrastinate now!

On Fri, 11 Mar 2011 22:29:59 +0000, John wrote:

Lucky you - although the Combi at the Scout Hut provides adequate heat
to the radiators, it fails to give anything other than tepid water out
of the taps event when it is turned up to max and the taps down to the
lowest flow that triggers the boiler.

That's called a fault.

--
John Stumbles

Religion is like a penis. It is fine to have one. It's ok to be proud of
it.
Just don't wave it around in public or try to jam it down my child's
throat.

On Fri, 11 Mar 2011 14:33:20 -0800, Mathew Newton wrote:

If you are going to draw comparisons you need to be thorough on both
sides. You have omitted the potential issues you may face with the
secondary heat exchanger and diverter valve that the combi introduces.
Also, the lack of any backup hot water availability should the boiler
breakdown.
....
Besides which, you really ought to be comparing against a modern
unvented cylinder as these address most of your concerns about
'conventional' systems - heat loss, flow rate, pressure, float valves
etc.

Unvented cylinders introduce their own complexity - pressure and
temperature relief valves, pressure-reducing valves, expansion vessels or
bubbles, safety override zone valves ...

Unfortunately when some of these items fail they can, in extreme cases,
reduce the safety of the unvented cylinder. Like nuclear power plants
these are normally quite safe ...


--
John Stumbles

Religion is like a penis. It is fine to have one. It's ok to be proud of
it.
Just don't wave it around in public or try to jam it down my child's
throat.






--
John Stumbles

militant pacifist

John wrote:
In article , Triffid
writes
harry wrote:
On Mar 11, 5:55 pm, "Triffid" wrote:
John Rumm wrote:
On 11/03/2011 14:56, harry wrote:
On Mar 11, 9:10 am, wrote:
OK, this changes from time to time I guess.
I may be getting a new combi boiler , about 30kW.
Up to a 1000 quids.
What is the most reliable boiler around at the moment for that
spec ? I.e. one that has the vaguest hope of lasting 10 years (I
know its ridiculous !)
Gas chap recommends Vaillant ...
Cheers,
Simon.

Don't bother with a combi. They are ****e of the devil. Put in a

You seem determined to steal dribble's crown harry.

conventional system ie with roof tanks and the HW storage tank
(well lagged). There's such a thing as too much technology. You
will still have to have a condensing boiler. It will cost you
more but there will be far less trouble and expense with repairs
and spare parts.

Huh?

What is the difference between a system boiler, and a combi?
Answer a small PHE, and a diversion valve and a flow switch.

What do you need to make a system boiler usable with a cylinder?
Zoning valves of some description. So the overall difference in
*system* complexity is approaching nil.

This also means you can install a solar hot water roof panel
which you can't with a combi. Also your bath will fill quickly.

The problem with all these numpty responses of "combi = good all
else evil" and their inverse, is they ignore the real world. There
are plenty of cases where one type of system is going to be vastly
preferable to the other, and to blindly insist on only the one
"allowable" solution demonstrates either ignorance or stupidity.

I agree. It's horses for courses. A condensing combi suits my
household because there is only one bathroom and just the two of
us. If we had an en-suite and wanted to shower at the same time, a
conventional storage system would probably be a better bet.

--
Kev- Hide quoted text -

- Show quoted text -

Combi boilers were made for one purpose only. To fit in new houses.
Cheaper than a conventional system and can be fitted with
semiskilled labour.

Absolutely stupid removing an existing DHW cylinder/header tank(s)
just to put in a combi.

Keep It Stupid Simple is always the way to go. Minimum technology
to achieve requirements.

Well, I hear what you say, but the significant advantage for us was
being able to get rid of the airing cupboard in the bathroom and
replace it with a walk-in shower. Because the new shower has clear
glass doors it has made the bathroom appear much larger as well.

Having instant hot water always on tap is also a bonus.

I agree with the need to keep things simple - and our plumbing
system is now a lot simpler than it was when it had two header tanks
in the loft and a hot water cylinder in the airing cupboard. (I got
£75 scrap for the copper tank and redundant pipework when the job
was done)

There is now no float valves to stick or go wrong in the loft, no
chance of any leaks or bursts in the loft, no motorised valves in
the system to stick or go wrong.

I couldn't believe the amount of gunge there was in the bottom of
the cold water tanks in the loft either!

Lucky you - although the Combi at the Scout Hut provides adequate heat
to the radiators, it fails to give anything other than tepid water out
of the taps event when it is turned up to max and the taps down to the
lowest flow that triggers the boiler.

I was very sceptical about whether I would be happy with a combi because
both my father and my mother-in-law had lived in houses with combis that
behaved exactly as you describe. In my father's bungalow it could take the
best part of an hour to fill his bath!

I think the problem is that replacement boilers are very much a 'distress
purchase' and, consequently, many people go for the cheapest option - a
boiler with the minimum power rating possible for the premises in question.
Also, the early combis were inherently poor anyway.

Combi technology (in particular in relation to the heat exchangers) has
advanced considerably.

If I visit the Worcester Bosch website and complete their 'find a boiler'
questionaire, they recommend the 24 kw Greenstar Junior boiler for my
3-bed/1 bathroom house. In fact I had a 30 kw Greenstar CDi installed. The
greater the power, the higher the flowrate at a given temperature of
course - and we find that the flow and temperature from the taps is more
than adequate. The domestic hot water thermostat on the boiler is set at the
'eco' level which is only about 1/3rd of the way up from minimum - and is
still fine. When the hot tap is running you cannot hold your hand in the
flow - it is too hot.

It's a pity, I think, that many people have been put off buying a combi
because of experiences with older, inadequately powerful, boilers.

--
Triff

Triffid ) wibbled on Saturday 12 March 2011 09:39:


I was very sceptical about whether I would be happy with a combi because
both my father and my mother-in-law had lived in houses with combis that
behaved exactly as you describe. In my father's bungalow it could take the
best part of an hour to fill his bath!

That is poor. My temporary instant 9kW electric heater fills my bath in 25
minutes and that is what I would consider poor...

--
Tim Watts

harry ) wibbled on Saturday 12 March 2011 08:40:

On Mar 12, 12:48 am, Andy Dingley wrote:
On Mar 11, 3:42 pm, "Triffid" wrote:

Prior to switching I was of the 'don't touch a combi with a barge-pole'
school of thought. I was persuaded by the argument that modern
condensing combis are a dramatic improvement on the earlier efforts.

It's not condensing that made combis work, it was building them of
adequate power. This has been usual practice for the last 15+ years
and competently specified combis, built by competent makers (i.e. no
Ravenheats) have worked well ever since. The old problematic ones were
just too small.

If you want a multi-fuel system with solar or solid input too, then
you do still need some sort of thermal store. If you're designing a
purely gas system, then combis are the way to go.

In only a few years gas will be too expensive for heating. (Libya is
the start) The is no such thing as purely gas,we all need electricity
in the house. This leads to premium payments for the first bit/meter
rental for both gas and electric.
So therefore gas is not the way to go at all. Zero gas and zero gas
meter rentals is the way to go.
Heat pumps and electricity are the way to. Zero maintenance and
little to go wrong. Run off PV panels on the roof if you like.
Don't be a lemming, be ahead of the proles.

The age of gas is finished.

Well, I don't know where it is all going, but my thermal store plan contains
3 x 3kW immersion heaters - primarily as backup against boiler failure, but
it's enough to run the system if the tide turns. Seems the tide isn't far
off regarding Economy 7 vs gas - I can see me operating a hybrid at some
point, electric charge overnight, gas for top up in the day. And yes, I do
have a dry coil I could inject some other heat source into later...

--
Tim Watts

In article
,
Andy Dingley wrote:
If you want a multi-fuel system with solar or solid input too, then
you do still need some sort of thermal store. If you're designing a
purely gas system, then combis are the way to go.

Maybe if you don't have a bath.

--
*Virtual reality is its own reward *

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

Dave Plowman (News) wrote:
In article
,
Andy Dingley wrote:
If you want a multi-fuel system with solar or solid input too, then
you do still need some sort of thermal store. If you're designing a
purely gas system, then combis are the way to go.

Maybe if you don't have a bath.

Our WB 30CDi has a flow-rate of 13.1 litres per minute at 35 deg.
temperature rise. It only takes a little longer to fill the bath than our
old conventional system did (and you can keep 'topping up' with hot water
all night long if you wish - no need to wait for the tank to heat up again.

--
Triff

In article ,
Triffid wrote:
Maybe if you don't have a bath.

Our WB 30CDi has a flow-rate of 13.1 litres per minute at 35 deg.
temperature rise. It only takes a little longer to fill the bath than
our old conventional system did (and you can keep 'topping up' with hot
water all night long if you wish - no need to wait for the tank to heat
up again.

It depends on many variables. There are header tank systems around with
not enough head - but round here the mains flow rate is poorer than some.

I can't see why you'd want to top up a bath anyway if it's filled with the
temperature you want to start with. But even if you did, any decent
storage system should be able to. With a fast recovery cylinder your
boiler can heat the water nearly as fast as a combi does.

Basically, no instant water heating system can cope with the possible
*peak* load/flow in the average house. A storage system can.

--
*Virtual reality is its own reward*

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

In article ,
John Rumm wrote:
Our WB 30CDi has a flow-rate of 13.1 litres per minute at 35 deg.
temperature rise. It only takes a little longer to fill the bath than
our old conventional system did (and you can keep 'topping up' with hot
water all night long if you wish - no need to wait for the tank to heat
up again.

We have a conventional storage system at the moment - takes about half
an hour to fill a bath!

All that says is it's poorly designed.

--
*Sleep with a photographer and watch things develop

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

Dave Plowman (News) wrote:
In article ,
Triffid wrote:
Maybe if you don't have a bath.

Our WB 30CDi has a flow-rate of 13.1 litres per minute at 35 deg.
temperature rise. It only takes a little longer to fill the bath than
our old conventional system did (and you can keep 'topping up' with
hot water all night long if you wish - no need to wait for the tank
to heat up again.

It depends on many variables. There are header tank systems around
with not enough head - but round here the mains flow rate is poorer
than some.

I can't see why you'd want to top up a bath anyway if it's filled
with the temperature you want to start with. But even if you did, any
decent storage system should be able to. With a fast recovery
cylinder your boiler can heat the water nearly as fast as a combi
does.

Basically, no instant water heating system can cope with the possible
*peak* load/flow in the average house. A storage system can.

I accept that there are pros and cons for both systems. And whilst a combi
system may suit one household - it may not suit another.

All I can do is repeat that it is now three years since we switched from a
storage system to a combi - and we have had no problems and no regrets. But
there are only two of us in the house - and only the one bathroom.

--
Triff

On Mar 12, 10:30*am, "Dave Plowman (News)"
wrote:
combis are the way to go.

Maybe if you don't have a bath.

Rubbish, and has been for decades.

We're running what might be the world's oldest Worcester Bosch combi
(there's a plaque on it from the Newcomen Society) and that fills a
bath just fine. Sure, the first combis had capacity problems that made
them a problem for filling baths, but that's way in the past now.