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  #1   Report Post  
Mika
 
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Default Condensing Boiler problems

Hiya All,

Just thought I'd share some info on condensing boilers with everyone,
and get some feedback.

I have been shopping around to get my old cast-iron open vent boiler
system changed to a direct combi system, and considered a condensing
boiler, Anyway, cut a long story short, found that Graham Group
(www.graham-group.co.uk) are doing the "Big Green Boiler Scheme" and
you can get a condensing boiler at a discounted rate (very good rates
they are too!).

Anyway, was just about to buy one through the scheme (Vaillant EcoMax
824), and was told by a friend to phone a guy who works for British
Gas, doing their boiler replacement scheme. He's going around fitting
condensing boilers for British Gas, and doing work on the side for
cash. I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling" and
"replacing" condensing boilers because of reliability issues. He also
mentioned that the "Part L" regs will be extended for another 3 years,
so new dwellings will not be required until 2007, not the April 2005
the goverment has publicised.

Any feedback on these rumors?

Conclusion....I'm going for a Glow-worm (now owned by Vaillant) 30Ci
Plus from "Mr Central Heating" (http://www.mrcentralheating.com/) with
the usual 7 rads and pipe pack (£735 including VAT). My thinking is
stick with what works, rather than go for new technology, and possibly
upgrade (if I'm still in the house) some years down the line.

Your feedback/comments welcome.

Mika
  #2   Report Post  
Tony Bryer
 
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Default Condensing Boiler problems

In article , Mika
wrote:
I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling"
and "replacing" condensing boilers because of reliability issues.

If he's talking about Potterton Envoys this could be true.
Otherwise condensing boilers that use the downfiring design should
be more reliable as they are effectively self cleansing

He also mentioned that the "Part L" regs will be extended for
another 3 years, so new dwellings will not be required until
2007, not the April 2005 the goverment has publicised.


The Northern Ireland Part F (aka Part L in E&W) consultation paper
published last month confirms the intention to enforce the April
2005 date and states that they intend to do the same in NI.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser
http://www.sda.co.uk/qsedbuk.htm


  #3   Report Post  
Tony Bryer
 
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Default Condensing Boiler problems

In article , Mika
wrote:
found that Graham Group (www.graham-group.co.uk) are
doing the "Big Green Boiler Scheme" and you can get a
condensing boiler at a discounted rate (very good rates
they are too!).


Given that their undiscounted price for a Keston Celsius is
£1,043.28+VAT v. £635+VAT at B&G Heating I should hope so!

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser
http://www.sda.co.uk/qsedbuk.htm


  #4   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Mika" wrote in message
om...
Hiya All,

Just thought I'd share some info on condensing boilers with everyone,
and get some feedback.

I have been shopping around to get my old cast-iron open vent boiler
system changed to a direct combi system, and considered a condensing
boiler, Anyway, cut a long story short, found that Graham Group
(www.graham-group.co.uk) are doing the "Big Green Boiler Scheme" and
you can get a condensing boiler at a discounted rate (very good rates
they are too!).

Anyway, was just about to buy one through the scheme (Vaillant EcoMax
824), and was told by a friend to phone a guy who works for British
Gas, doing their boiler replacement scheme. He's going around fitting
condensing boilers for British Gas, and doing work on the side for
cash. I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling" and
"replacing" condensing boilers because of reliability issues.


There are numerous makes of condensing boilers. What make(s) In general, a
condensing boiler is "no" more complex than a regular boiler. Anyone who
says differently knows ***k all about them.

BG had the Ideal ICOS on their list but were not pushing it because of
initial reliability problems. Ideal addressed the issue by taking the fan
control off the main control board and now all is fine.

He also mentioned that the "Part L" regs will be extended for another 3

years,
so new dwellings will not be required until 2007, not the April 2005
the goverment has publicised.


So far 2005.

Any feedback on these rumors?

Conclusion....I'm going for a Glow-worm (now owned by Vaillant) 30Ci
Plus from "Mr Central Heating" (http://www.mrcentralheating.com/) with
the usual 7 rads and pipe pack (£735 including VAT). My thinking is
stick with what works, rather than go for new technology, and possibly
upgrade (if I'm still in the house) some years down the line.

Your feedback/comments welcome.


The Glow Worm is a good boiler, with Vaillant parts in it. Ideal have
Vaillant parts and some boilers to be introduced will be pure Vaillant
except for the badge. Ideal boast that no part in the boiler )(except the
heat exchange) takes more than 15 minutes to change. So if you are charged 2
hours to replace something question it.


  #5   Report Post  
Christian McArdle
 
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Default Condensing Boiler problems

cash. I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling" and
"replacing" condensing boilers because of reliability issues.


Oh dear. Another Luddite installer who harks back to the cast iron heaps of
**** that have been installed since time immemorial. Yes, many of the early
condensing boilers were bad. Things have moved on. Modern condensing boilers
aren't "new technology" any more. They're on their third generation and no
less reliable than modern non-condensing boilers.

The only problem with the EcoMax 824 is that it won't fill a bath any time
soon. Still good for showers, if that's your thing (much better than any
gravity fed traditional system). If you are a bath a day type, consider
getting a non-combi system, or you'll spend your life watching the dribble
out of the tap.

Christian.





  #6   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Christian McArdle" wrote in message
. net...
cash. I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling" and
"replacing" condensing boilers because of reliability issues.


Oh dear. Another Luddite installer who harks back to the cast iron heaps

of
**** that have been installed since time immemorial. Yes, many of the

early
condensing boilers were bad. Things have moved on. Modern condensing

boilers
aren't "new technology" any more. They're on their third generation and no
less reliable than modern non-condensing boilers.

The only problem with the EcoMax 824 is that it won't fill a bath any time
soon. Still good for showers, if that's your thing (much better than any
gravity fed traditional system). If you are a bath a day type, consider
getting a non-combi system, or you'll spend your life watching the dribble
out of the tap.


More misinformation. There are high flow rate combi's that will fill a bath
zippo.


  #7   Report Post  
Christian McArdle
 
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Default Condensing Boiler problems

More misinformation. There are high flow rate combi's that will fill
a bath zippo.


They're not proper combis, they're just sometimes called so by the marketing
department. The proper high rate combis are actually boilers integrated with
an internal heat bank. There's nothing wrong with them, provided they are
sized to not run out of store filling a bath at full pelt.

Christian.


  #8   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Christian McArdle" wrote in message
. net...
More misinformation. There are high flow rate combi's that will fill
a bath zippo.


They're not proper combis,


A combi is a heating and hot water system all in one box with no external
Tanks or cylinders. Hence the name "combi" from combination. It is a "one
box" solution. You just connect up the cold pipe in, hot pipe out and a
flow * return to the rads with a gas pipe. They save a hell of a lot of
time and space and are cheaper to install.

The proper high rate combis are actually
boilers integrated with an internal heat bank.


Some are, some have an integral unvented cylinder inside the box too. The
ECO-Hometec gives a flowrate of 22 litre/minute, which is infinitely
continuous, if that is what you mistakenly mean by a "proper combi".

There's nothing wrong with them, provided they are
sized to not run out of store filling a bath at full pelt.


You lack knowledge of the various types of "combi" available. This is very
sad,



  #9   Report Post  
Christian McArdle
 
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Default Condensing Boiler problems

A combi is a heating and hot water system all in one box with no
external Tanks or cylinders. Hence the name "combi" from
combination.


Yes, but the term does now seem to mean an instantaneously heated system,
rather than a storage based one. However, it is only a name and I see no
reason to argue over that. The important thing is matching the performance
of the system to the expectations of the user.

Some are, some have an integral unvented cylinder inside the box too.
The ECO-Hometec gives a flowrate of 22 litre/minute, which is
infinitely continuous, if that is what you mistakenly mean by a
"proper combi".


22 lpm is too slow for me. I'd rather lose the infinitely continuous and
gain immediate gratification at the expense of a little loft space. However,
22 lpm would run a pretty excellent shower, or two good ones, so could be
very useful for a household with 2 showers where baths are infrequent.

Some are, some have an integral unvented cylinder inside the box too.


The only one I've seen is the Keston Duet, but there isn't an overall box.
You can see the separate cylinder, boiler and framework. Are there any other
makes? I would have thought that an integrated heat bank would generally
make more sense for a unit designed down to a small size in a common casing,
especially when they'd rather they could be installed by a CORGI without
further qualifications.

Christian.



  #10   Report Post  
Tony Bryer
 
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Default Condensing Boiler problems

In article , Christian
McArdle wrote:
Some are, some have an integral unvented cylinder inside the box too.


The only one I've seen is the Keston Duet, but there isn't an overall box.
You can see the separate cylinder, boiler and framework. Are there any other
makes? I would have thought that an integrated heat bank would generally
make more sense for a unit designed down to a small size in a common casing,


You mean like a Potterton Powermax?

http://www.potterton.co.uk/products/...owermaxHE.html

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm




  #11   Report Post  
Andy Hall
 
Posts: n/a
Default Condensing Boiler problems

On 9 Mar 2004 04:28:57 -0800, (Mika) wrote:

Hiya All,

Just thought I'd share some info on condensing boilers with everyone,
and get some feedback.

I have been shopping around to get my old cast-iron open vent boiler
system changed to a direct combi system, and considered a condensing
boiler, Anyway, cut a long story short, found that Graham Group
(
www.graham-group.co.uk) are doing the "Big Green Boiler Scheme" and
you can get a condensing boiler at a discounted rate (very good rates
they are too!).

Anyway, was just about to buy one through the scheme (Vaillant EcoMax
824), and was told by a friend to phone a guy who works for British
Gas, doing their boiler replacement scheme. He's going around fitting
condensing boilers for British Gas, and doing work on the side for
cash.
I mentioned that I was interested in the condensing boiler as a
replacement, which he said in all honesty that BG are "recalling" and
"replacing" condensing boilers because of reliability issues.


This may be true with very early generation UK made condensing
products where an attempt was made to bolt condensing technology on to
existing designs by adding a second heat exchanger.
Naturally this failed because the condensate is mildly acidic and a
properly designed exchanger is needed.

It isn't true of modern products of good quality based on designs from
or manufactured in Germany or Holland. They have had them in those
countries for years.

I would take remarks from anybody at BG with a pinch of salt,
especially anybody evading tax by doing jobs on the side for cash.


He also
mentioned that the "Part L" regs will be extended for another 3 years,
so new dwellings will not be required until 2007, not the April 2005
the goverment has publicised.


That remains to be seen. It is likely to be a boiler replacement or
new installation requirement.




Any feedback on these rumors?

Conclusion....I'm going for a Glow-worm (now owned by Vaillant) 30Ci
Plus from "Mr Central Heating" (http://www.mrcentralheating.com/) with
the usual 7 rads and pipe pack (£735 including VAT). My thinking is
stick with what works, rather than go for new technology, and possibly
upgrade (if I'm still in the house) some years down the line.

Your feedback/comments welcome.


An opportunity lost, I would say. If you buy a good quality
condensing boiler it will do a good job and reduce energy costs.




Mika


..andy

To email, substitute .nospam with .gl
  #12   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Christian McArdle" wrote in message
. net...

A combi is a heating and hot water system all in one box with no
external Tanks or cylinders. Hence the name "combi" from
combination.


Yes, but the term does now seem to mean an instantaneously heated system,
rather than a storage based one. However, it is only a name and I see no
reason to argue over that. The important thing is matching the performance
of the system to the expectations of the user.

Some are, some have an integral unvented cylinder inside the box too.
The ECO-Hometec gives a flowrate of 22 litre/minute, which is
infinitely continuous, if that is what you mistakenly mean by a
"proper combi".


22 lpm is too slow for me. I'd rather lose the infinitely continuous and
gain immediate gratification at the expense of a little loft space.

However,
22 lpm would run a pretty excellent shower, or two good ones, so could be
very useful for a household with 2 showers where baths are infrequent.

Some are, some have an integral unvented cylinder inside the box too.


The only one I've seen is the Keston Duet, but there isn't an overall box.
You can see the separate cylinder, boiler and framework. Are there any

other
makes?


Ariston, Glow Worm did one. The Powermax is now an unvented cylinder and now
classed asa combi, and a few others around. The unvented cylinders store
water at approx 80C blending it down.

I would have thought that an integrated heat bank would generally
make more sense for a unit designed down to a small size in a common

casing,
especially when they'd rather they could be installed by a CORGI without
further qualifications.


CORGI doesn't come into it. A thermal store/combi has the advantage that
the store can be any shape for better packaging and is two stage in output.
When the store is depleted it reverts to approx 11-12 litres/min.


  #13   Report Post  
IMM
 
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Default Condensing Boiler problems


"Christian McArdle" wrote in message
. net...

A combi is a heating and hot water system all in one box with no
external Tanks or cylinders. Hence the name "combi" from
combination.


Yes, but the term does now seem to mean an
instantaneously heated system,
rather than a storage based one.


To clarify for you:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure. To confuse a little, some can run at very low
pressures and even off tanks. Generally most are fed from the mains. It is
generally a matter of mounting the boiler and connect up the pipes. The
expert designers have done the hard work for you and put all in one case.

There are three types of combi:

1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

2) Unvented Cylinder Combi -

An unvented cylinder is a similar to a conventional cylinder but run off the
high-pressure cold mains. A combi with an integral unvented cylinder has
approx 60 litre cylinder heated to approx 80C, with a quick recovery coil
that takes all the boilers output. A fast acting cylinder thermostat ensures
the boiler pumps heat into the cylinder ASAP with a recovery rate from cold
around 5-8 mins (Ariston claim 8 mins). The 80C water is blended down to
about 45-50C. e.g's, Ariston Genus 27 Plus, Glow Worm, Powermax.

3) Heat Bank Combi -

Incoming water is instantly heated running through a plate heat exchanger
(as is most instantaneous combi's) that takes its heat from a "domestic hot
water only" store of water at approx 80C (instantaneous combi's take the
heat from a heat-exchanger heater via the burner). A fast acting thermostat
ensures the boiler pumps all of its heat into the store ASAP with a recovery
rate about 5-8 mins from cold. The 80C water is blended down to about
45-50C. They are generally two stage, in that when the thermal store is
exhausted it reverts to what the bunrer can produce, which isapprox 11-12
litre/minute. e.g. Vokera & Worcester floor standing models (standard
washing machine sizes).

N.B. The heat bank is a variation of a thermal store, but is "not" a thermal
store in the conventional sense in that a coil carrying cold mains water
runs though a store of hot water kept at about 80C. Heat-banks are far more
efficient and give higher flowrates than conventional coiled thermal stores.
The stainless steel plate heat-exchangers do not scale up so easily.

4) Combined Primary Storage Unit
(Not classed as a combi, but a derivative of a combi, but still a one box
solution, so still in the same family)

These are a combination of a large thermal store and boiler in one casing.
The units are large (larger than standard washing machine size) and floor
mounted. The heating is taken off the thermal store, with in many cases the
DHW taken off the store using a plate heat-exchanger (heat-bank). Unlike
the Heat-bank in 3) above the thermal store supplies heating and DHW. They
are available from 1 to 2.5 bathroom models. Gledhill do an excellent
condensing version, the Gulfsream 2000. http://www.gledhill.net

Nos. 2) 3) & 4) have high flowrates. No. 1 "generally" has low flowrates
but there are always exceptions and some can be high - e.g. ECO-Hometec
infinitely continuous combi; actually has a very high flowrate.

Nos 2), 3) & 4) use stored water, but in different ways. Unlike No. 1 they
will eventually run cold, but that takes quite a time, hence they are
referred to as "two bathroom" models, having the ability to fill two baths
with very fast recovery rates. As hot water is being drawn off the high
rating burner is also reheating. Very rare do these combi's run out of hot
water in average use. When taking one shower the burner may be re-heating
faster than what can be drawn-off.

There are combi's that give hot water and heating simultaneously - Combined
Primary Storage Units do. Most don't as they are hot water priority.


  #14   Report Post  
geoff
 
Posts: n/a
Default Condensing Boiler problems

In message , IMM
writes


There are numerous makes of condensing boilers. What make(s) In general, a
condensing boiler is "no" more complex than a regular boiler. Anyone who
says differently knows ***k all about them.

BG had the Ideal ICOS on their list but were not pushing it because of
initial reliability problems. Ideal addressed the issue by taking the fan
control off the main control board and now all is fine.


Really ?

I can categorically state that that is not correct

Considering the age of a majority of condensing boilers available in the
UK, I would call most of them a disaster



--
geoff
  #15   Report Post  
geoff
 
Posts: n/a
Default Condensing Boiler problems

In message , Tony Bryer
writes
In article , Christian
McArdle wrote:
Some are, some have an integral unvented cylinder inside the box too.


The only one I've seen is the Keston Duet, but there isn't an overall box.
You can see the separate cylinder, boiler and framework. Are there any other
makes? I would have thought that an integrated heat bank would generally
make more sense for a unit designed down to a small size in a common casing,


You mean like a Potterton Powermax?

http://www.potterton.co.uk/products/...owermaxHE.html


This page cannot be displayed - see, even the internet has morals
--
geoff


  #16   Report Post  
Jim Hatfield
 
Posts: n/a
Default Condensing Boiler problems

On Tue, 9 Mar 2004 21:23:02 -0000, "IMM" wrote:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure.


Does this mean that all the radiators are at mains pressure? If so,
does changing from a conventional system to a combi mean replacing all
the radiators?

Jim
  #17   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"geoff" wrote in message
...
In message , IMM
writes


There are numerous makes of condensing boilers. What make(s) In

general, a
condensing boiler is "no" more complex than a regular boiler. Anyone who
says differently knows ***k all about them.

BG had the Ideal ICOS on their list but were not pushing it because of
initial reliability problems. Ideal addressed the issue by taking the

fan
control off the main control board and now all is fine.


Really ?


Yes. According to the Ideal rep.

Considering the age of a majority of condensing boilers available in the
UK, I would call most of them a disaster


I wouldn't.


  #18   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Jim Hatfield" local@localhost wrote in message
...
On Tue, 9 Mar 2004 21:23:02 -0000, "IMM" wrote:

Firstly, a combi is a "combination" of the heating and water system in

one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure.


Does this mean that all the radiators are at mains pressure?


No, not at all. The hot water and the rads are separate.

If so, does changing from a conventional system
to a combi mean replacing all the radiators?


No.


  #19   Report Post  
Andy Hall
 
Posts: n/a
Default Condensing Boiler problems

On Tue, 09 Mar 2004 22:53:33 +0000, Jim Hatfield local@localhost
wrote:

On Tue, 9 Mar 2004 21:23:02 -0000, "IMM" wrote:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure.


Does this mean that all the radiators are at mains pressure? If so,
does changing from a conventional system to a combi mean replacing all
the radiators?

Jim


No it doesn't. The radiators form a separate circuit.

People often make the confusion when the word "conventional" is used.

There are actually at least four parameters defining a boiler where
the word "conventional" is used to mean that it doesn't have/do the
particular thing.

Open vented vs. sealed
=====================

This means that the primary heating circuit is topped up and expansion
allowed using a small tank in the loft (open vented) vs. circuit
topped up via a non-return valve from the mains - connected when
required - and expansion done with a closed vessel with diaphragm.

non-combi vs. combi
==================

whether or not the boiler (within its case) heats the domestic hot
water directly or not - description by IMM.

non condensing vs condensing
===========================

Whether or not the boiler has an internal arrangement to recover the
latent heat of condensation from the exhaust gases and thence achieve
a higher efficiency.

non system vs system
===================

whether or not the boiler has the pump and possibly controls and
expansion vessel inside the case.


There are typical correlations. Combi boilers more often than not
require to run on sealed radiator circuits. They quite often have the
expansion vessel and pump inside as well.

So the real question is more one of "does a sealed system imply a
radiator change?" and the answer to that is no, as long as they are in
good condition. Radiator valves may need to be changed if they are
old and tending to weep.

The pressure used is typically under 2 bar so rather less than mains
pressure and not hugely greater than an open vented system in the
scheme of things. It is possible and may be beneficial to convert an
open system to sealed anyway if the boiler will allow it (read boiler
spec). It eliminates air being drawn in to the system, makes
filling easier and saves a little bit of space.

More details at Ed Sirett's sealed system FAQ







..andy

To email, substitute .nospam with .gl
  #20   Report Post  
Dave Plowman
 
Posts: n/a
Default Condensing Boiler problems

In article ,
Christian McArdle wrote:
The only problem with the EcoMax 824 is that it won't fill a bath any
time soon. Still good for showers, if that's your thing (much better
than any gravity fed traditional system).


I take it you've never tried the likes of an Aqualisa shower fed 22mm from
a gravity fed system with a reasonable head?

--
*I love cats...they taste just like chicken.

Dave Plowman London SW 12
RIP Acorn


  #22   Report Post  
Michael Chare
 
Posts: n/a
Default Condensing Boiler problems

"Andy Hall" wrote in message
...

non system vs system
===================

whether or not the boiler has the pump and possibly controls and
expansion vessel inside the case.


From what I have seen some boiler manufacturers just use the word 'system' to
denote boilers which would be better described as 'sealed system'.

Michael Chare


  #23   Report Post  
Andy Hall
 
Posts: n/a
Default Condensing Boiler problems

On Wed, 10 Mar 2004 00:52:28 +0000 (UTC), "Michael Chare"
wrote:

"Andy Hall" wrote in message
.. .

non system vs system
===================

whether or not the boiler has the pump and possibly controls and
expansion vessel inside the case.


From what I have seen some boiler manufacturers just use the word 'system' to
denote boilers which would be better described as 'sealed system'.

Michael Chare


Teminology is used loosely, which is what makes it confusing.

You really have to look past the names given and see what is actually
inside,

There are system boilers which will only run on open vented circuits
(not so many now) and some that will run on both as well as sealed
only.

Unfortunately, "system" seems to be used to describe anything which
contains more than a heat exchanger, gas valve, safety device and
thermostat (i.e. more than the bare minimum)



..andy

To email, substitute .nospam with .gl
  #24   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Andy Hall" wrote in message
...
On Wed, 10 Mar 2004 00:52:28 +0000 (UTC), "Michael Chare"
wrote:

"Andy Hall" wrote in message
.. .

non system vs system
===================

whether or not the boiler has the pump and possibly controls and
expansion vessel inside the case.


From what I have seen some boiler manufacturers just use the word

'system' to
denote boilers which would be better described as 'sealed system'.

Michael Chare


Teminology is used loosely, which is what makes it confusing.

You really have to look past the names given and see what is actually
inside,

There are system boilers which will only run on open vented circuits
(not so many now) and some that will run on both as well as sealed
only.

Unfortunately, "system" seems to be used to describe anything which
contains more than a heat exchanger, gas valve, safety device and
thermostat (i.e. more than the bare minimum)


Terminology has now settled. A system boiler has a pump and pressure vessel
inside, so is only used for a sealed system - some may have a built-in
pressure loop, others do not. You just connect it up and still have to
install 3-way or 2-way zone valves. A "heating" boiler has no pump or
pressure vessel and can be open vented or sealed. You have to install all
the relevant pumps and kit yourself externally.

The terms heat bank and thermal store are still mixed up too:

- A heat bank uses a pump and a plate heat exchanger for the DHW take off.
- A thermal store has in integral immersed coil.


  #25   Report Post  
Dave Plowman
 
Posts: n/a
Default Condensing Boiler problems

In article ,
Andy Hall wrote:
Unfortunately, "system" seems to be used to describe anything which
contains more than a heat exchanger, gas valve, safety device and
thermostat (i.e. more than the bare minimum)


I can see the advantage to an installer of having everything in one, but
given that the pump and motorised valve(s) are likely to need replacing
before the boiler (although given the problems some have this might not be
the case), wouldn't external mounting actually be the better option if
space isn't at a premium?

--
*Why does the sun lighten our hair, but darken our skin?

Dave Plowman London SW 12
RIP Acorn


  #26   Report Post  
Tony Bryer
 
Posts: n/a
Default Condensing Boiler problems

In article , Geoff wrote:
You mean like a Potterton Powermax?

http://www.potterton.co.uk/products/...owermaxHE.html


This page cannot be displayed - see, even the internet has morals


It works from here.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm


  #27   Report Post  
Andy Hall
 
Posts: n/a
Default Condensing Boiler problems

On Wed, 10 Mar 2004 09:19:47 -0000, "IMM" wrote:




Terminology has now settled.


Yes and no. You still see the terms used loosely.


A system boiler has a pump and pressure vessel
inside, so is only used for a sealed system - some may have a built-in
pressure loop, others do not. You just connect it up and still have to
install 3-way or 2-way zone valves. A "heating" boiler has no pump or
pressure vessel and can be open vented or sealed. You have to install all
the relevant pumps and kit yourself externally.

The terms heat bank and thermal store are still mixed up too:

- A heat bank uses a pump and a plate heat exchanger for the DHW take off.
- A thermal store has in integral immersed coil.

A heat bank can also have a coil if it's an indirect one - in order to
separate the bulk water from the sealed primary


..andy

To email, substitute .nospam with .gl
  #28   Report Post  
Andy Hall
 
Posts: n/a
Default Condensing Boiler problems

On Wed, 10 Mar 2004 09:26:23 +0000 (GMT), Dave Plowman
wrote:

In article ,
Andy Hall wrote:
Unfortunately, "system" seems to be used to describe anything which
contains more than a heat exchanger, gas valve, safety device and
thermostat (i.e. more than the bare minimum)


I can see the advantage to an installer of having everything in one, but
given that the pump and motorised valve(s) are likely to need replacing
before the boiler (although given the problems some have this might not be
the case), wouldn't external mounting actually be the better option if
space isn't at a premium?


Having the pump internal allows it to be modulated as well by the
boiler controller, thus dropping the flow rate to match reduced output
as the boiler modulates down.

It would be even better if a standard like Opentherm became more
prevalent so that thermostats, pumps and other devices could be mixed
and controlled by different vendors' equipment and controllers.



..andy

To email, substitute .nospam with .gl
  #29   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Andy Hall" wrote in message
...
On Wed, 10 Mar 2004 09:19:47 -0000, "IMM" wrote:


Terminology has now settled.


Yes and no. You still see the terms used loosely.

A system boiler has a pump and pressure vessel
inside, so is only used for a sealed system - some may have a built-in
pressure loop, others do not. You just connect it up and still have to
install 3-way or 2-way zone valves. A "heating" boiler has no pump or
pressure vessel and can be open vented or sealed. You have to install

all
the relevant pumps and kit yourself externally.

The terms heat bank and thermal store are still mixed up too:

- A heat bank uses a pump and a plate heat exchanger for the DHW take

off.
- A thermal store has in integral immersed coil.

A heat bank can also have a coil if it's an indirect one - in order to
separate the bulk water from the sealed primary


I said for the DHW take off. A heat bank can be heated by electric
immersions if you want.


  #30   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"Andy Hall" wrote in message
...
On Wed, 10 Mar 2004 09:26:23 +0000 (GMT), Dave Plowman
wrote:

In article ,
Andy Hall wrote:
Unfortunately, "system" seems to be used to describe anything which
contains more than a heat exchanger, gas valve, safety device and
thermostat (i.e. more than the bare minimum)


I can see the advantage to an installer of having everything in one, but
given that the pump and motorised valve(s) are likely to need replacing
before the boiler (although given the problems some have this might not

be
the case), wouldn't external mounting actually be the better option if
space isn't at a premium?


Having the pump internal allows it to be modulated as well by the
boiler controller, thus dropping the flow rate to match reduced output
as the boiler modulates down.


Ideal say all the components of their boilers can be changed within 15
minutes. No need to change a full pump, just the pump head.

It would be even better if a standard like Opentherm became more
prevalent so that thermostats, pumps and other devices could be mixed
and controlled by different vendors' equipment and controllers.


And pigs will fly.




  #31   Report Post  
geoff
 
Posts: n/a
Default Condensing Boiler problems

In message , IMM
writes

"geoff" wrote in message
...
In message , IMM
writes


There are numerous makes of condensing boilers. What make(s) In

general, a
condensing boiler is "no" more complex than a regular boiler. Anyone who
says differently knows ***k all about them.

BG had the Ideal ICOS on their list but were not pushing it because of
initial reliability problems. Ideal addressed the issue by taking the

fan
control off the main control board and now all is fine.


Really ?


Yes. According to the Ideal rep.


I'm glad you didn't qualify to be a doctor


Considering the age of a majority of condensing boilers available in the
UK, I would call most of them a disaster


I wouldn't.


Well, you wouldn't would you?

--
geoff
  #32   Report Post  
geoff
 
Posts: n/a
Default Condensing Boiler problems

In message , Tony Bryer
writes
In article , Geoff wrote:
You mean like a Potterton Powermax?

http://www.potterton.co.uk/products/...owermaxHE.html


This page cannot be displayed - see, even the internet has morals


It works from here.

That was another NTL set top box crashes on my part

--
geoff
  #33   Report Post  
IMM
 
Posts: n/a
Default Condensing Boiler problems


"geoff" wrote in message
...
In message , IMM
writes

"geoff" wrote in message
...
In message , IMM


writes


There are numerous makes of condensing boilers. What make(s) In

general, a
condensing boiler is "no" more complex than a regular boiler. Anyone

who
says differently knows ***k all about them.

BG had the Ideal ICOS on their list but were not pushing it because of
initial reliability problems. Ideal addressed the issue by taking the

fan
control off the main control board and now all is fine.

Really ?


Yes. According to the Ideal rep.


I'm glad you didn't qualify to be a doctor


Considering the age of a majority of condensing boilers available in

the
UK, I would call most of them a disaster


I wouldn't.


Well, you wouldn't would you?


No I wouldn't.


  #34   Report Post  
Christian McArdle
 
Posts: n/a
Default Condensing Boiler problems

I take it you've never tried the likes of an Aqualisa shower fed 22mm
from a gravity fed system with a reasonable head?


The problem is that the gravity system can't provide the pressure. OK, if
well designed, they can provide good flow rates (i.e. for a Victorian style
drencher), put you'll never get a nice pounding from the pulse function
without a bit of push. That needs at least 1 bar, preferably more. That's
over 10m of head. Many people can't afford to buy an entire block of flats
so that a tank can go on the roof.

Christian.



  #35   Report Post  
Dave Plowman
 
Posts: n/a
Default Condensing Boiler problems

In article ,
Christian McArdle wrote:
I take it you've never tried the likes of an Aqualisa shower fed 22mm
from a gravity fed system with a reasonable head?


The problem is that the gravity system can't provide the pressure. OK,
if well designed, they can provide good flow rates (i.e. for a Victorian
style drencher), put you'll never get a nice pounding from the pulse
function without a bit of push. That needs at least 1 bar, preferably
more. That's over 10m of head. Many people can't afford to buy an entire
block of flats so that a tank can go on the roof.


It depends, I suppose, on what you want. I prefer a drenching to a high
pressure dribble.

--
*Any connection between your reality and mine is purely coincidental

Dave Plowman London SW 12
RIP Acorn


  #36   Report Post  
Ed Sirett
 
Posts: n/a
Default Condensing Boiler problems

On Thu, 11 Mar 2004 09:42:10 +0000, Christian McArdle wrote:

I take it you've never tried the likes of an Aqualisa shower fed 22mm
from a gravity fed system with a reasonable head?


The problem is that the gravity system can't provide the pressure. OK, if
well designed, they can provide good flow rates (i.e. for a Victorian style
drencher), put you'll never get a nice pounding from the pulse function
without a bit of push. That needs at least 1 bar, preferably more. That's
over 10m of head. Many people can't afford to buy an entire block of flats
so that a tank can go on the roof.


If you want serious flow and pressure buy a flat (on a losih storey) in a
large 1930's block with _central_ heating.

What is adeqaute flow/pressure for a shower is a matter of personal taste
and expectations (fulfilled/unfulfilled).


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html


  #37   Report Post  
Toby
 
Posts: n/a
Default Condensing Boiler problems

Ed Sirett wrote:
If you want serious flow and pressure buy a flat (on a losih storey)
in a large 1930's block with _central_ heating.


Ooh yes yes yes. My old Bayswater flat in a mansion block, you could fill
the deep bath faster than you could get undressed.

--
Toby.

'One day son, all this will be finished'


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