Any help will be appreciated.

Got a combination boiler,it started leaking all over the place last
night.

Got an emergency plumber in today at £57 / half hour plus VAT.

He told me it's the heat exchanger ( will confirm this with Ideal
Boilers tomorrow) although he didn't pinpoint the leak.

He's quoting £1500 all in for a new boiler.

Our house is a small 3 bedroom end terrace - the current boiler size
is 90,000 Btu/h and the one he recommended is exactly the same size,
this is despite telling him we are extending next year and would need
a bigger boiler.

So.......any recommendations? Should I get a new boiler now (condensor
or combi) or should I get a new heat exchanger fitted as we'll be
extending next year and will have to get a new boiler anyway?

Thanx, Lod

On 7 Dec 2003 14:51:01 -0800, (lodtop) wrote:

Any help will be appreciated.

Got a combination boiler,it started leaking all over the place last
night.

Got an emergency plumber in today at £57 / half hour plus VAT.

He told me it's the heat exchanger ( will confirm this with Ideal
Boilers tomorrow) although he didn't pinpoint the leak.

He's quoting £1500 all in for a new boiler.

Our house is a small 3 bedroom end terrace - the current boiler size
is 90,000 Btu/h and the one he recommended is exactly the same size,
this is despite telling him we are extending next year and would need
a bigger boiler.

Not necessarily.

BTUs are a deprecated unit, but 90,000 of them equates to 26kW which
is a fairly powerful boiler for a small house.

Having said that, if it is an older property with solid brick walls
with no cavity or no cavity insulation, it may be close to its limit.
The only way that you could tell properly is by calculating the heat
losses and doing so properly. For an older property, by far the
largest losses are through the walls so it is important to check
properly and not rely on some plumber looking around and guessing with
a ready reckoner. The radiator manufacturers have programs on their
web sites to help calculate the heat losses. All you have to do is
measure the surfaces (floors, walls, windows) and plug them into the
program, room by room, choosing the correct material for each surface.
You'll then get a total heat loss for the property. Add about 20%
to this for boiler sizing.

When you add an extension, modern building regulations are going to
require cavity walls and double glazing and the heat losses in this
part are going to be a lot less (could be only a quarter) of the
equivalent size of existing house.




So.......any recommendations? Should I get a new boiler now (condensor
or combi) or should I get a new heat exchanger fitted as we'll be
extending next year and will have to get a new boiler anyway?

I would draw a line under the existing boiler and get a new one.
Generally the heat exchanger is one of the most expensive parts.

Are you happy with the hot water performance of the combi? If not,
and the water flow is adequate you could go for a larger one with more
output to hot water.

Modern condensing boilers (and you can get condensing combi boilers)
tend to have control systems which result in the boiler running at a
lower than full output (called modulation) to the heating when there
is less demand on a warmer day. For the hot water, and when required
for the heating, it will run at full power.

So it doesn't matter if you oversize the boiler for heating purposes
particularly. You could go for a 30-35kW boiler for example.

Whether the £1500 is a good price depends on what you would be
getting. It's worth spending a bit more for a decent condensing
product like Vaillant or others with a stainless steel heat exchanger
since these have a longer lifetime than most other materials.
You would most likely not get one of those fitted for £1500 though,


Certainly it is worth going for a condensing model as you'll shave
approx 25% or so off of your energy consumption if the existing boiler
is a fairly old type. Do make sure that the system is properly
flushed and dosed with corrosion inhibitor as this may have been a
contributing factor to the demise of your existing boiler.

Also, if you do have an older property, and it is practical, consider
insulating the insides of the outside walls. Something like 50mm
Celotex sheet would have an enormous difference with solid walls.








Thanx, Lod

..andy

To email, substitute .nospam with .gl

When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has actually
resulted in reduced calculated heat losses from the house. This is because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original wall,
despite have many times the surface area.

Christian.

On Wed, 10 Dec 2003 17:32:29 -0000, "Christian McArdle"
wrote:

When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has actually
resulted in reduced calculated heat losses from the house. This is because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original wall,
despite have many times the surface area.

Christian.


The area doesn't need to be much for there to be an improvement.

The U value of a plastered solid double brick wall is about 2 W/m^2.K

For a new wall it's 0.35 or 0.25, so almost a 10:1 difference.

For old single glazed windows the improvement with double glazed, low
emissivity glass is about 2.5:1, although the areas are smaller of
course.



..andy

To email, substitute .nospam with .gl

On Wed, 10 Dec 2003 18:31:34 +0000, Andy Hall wrote:

On Wed, 10 Dec 2003 17:32:29 -0000, "Christian McArdle"
wrote:

When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has actually
resulted in reduced calculated heat losses from the house. This is because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original wall,
despite have many times the surface area.

Christian.


The area doesn't need to be much for there to be an improvement.

The U value of a plastered solid double brick wall is about 2 W/m^2.K

For a new wall it's 0.35 or 0.25, so almost a 10:1 difference.

For old single glazed windows the improvement with double glazed, low
emissivity glass is about 2.5:1, although the areas are smaller of
course.

Not to mention the much reduced air changes which accounts for significant
part of the total heating demand.

--
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

"Ed Sirett" wrote in message
news
On Wed, 10 Dec 2003 18:31:34 +0000, Andy Hall wrote:

On Wed, 10 Dec 2003 17:32:29 -0000, "Christian McArdle"
wrote:

When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has
actually
resulted in reduced calculated heat losses from the house. This is
because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original
wall,
despite have many times the surface area.

Christian.


The area doesn't need to be much for there to be an improvement.

The U value of a plastered solid double brick wall is about 2 W/m^2.K

For a new wall it's 0.35 or 0.25, so almost a 10:1 difference.

For old single glazed windows the improvement with double glazed, low
emissivity glass is about 2.5:1, although the areas are smaller of
course.

Not to mention the much reduced air changes which accounts for significant
part of the total heating demand.

Very true. Air leakages account for 42% of heat loss in a modern house. An
old Victorian solid walled house with modern sealed double glazed windows
and doors is much tighter than the modern equivalent, which, with cavity
walls leaks far more. A prime leakage point is the window reveals and where
the joists penetrate the inner wall. This should be fully sealed up, but
never is.


---
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"Christian McArdle" wrote in message
. net...
When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has
actually
resulted in reduced calculated heat losses from the house. This is because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original wall,
despite have many times the surface area.

The old external uninsulated solid wall then becomes internal with a lot of
thermal mass. This, once charged with heat reduces the peaks of heat
demand.


---
--

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Version: 6.0.548 / Virus Database: 341 - Release Date: 05/12/2003

In article , IMM
writes

"Christian McArdle" wrote in message
.net...
When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has
actually
resulted in reduced calculated heat losses from the house. This is because
an uninsulated solid wall was appended by the heavily insulated 2 storey
extension, which had considerably lower heat loss than the original wall,
despite have many times the surface area.

The old external uninsulated solid wall then becomes internal with a lot of
thermal mass. This, once charged with heat reduces the peaks of heat
demand.
Unless the extension has a lower roof pitch than the original (using
dormer windows for the upstairs to maintain the same cill height) which
means you have a nasty cold radiator where by part of the original gable
wall is exposed but connected the rest of it which is now within the
house.

PS In all the house makeover, 'get rich quick' etc program, how come I
never hear Ms Beeny and others mentioning the magical word
'insulation' to make the property more comfortable?. Lets face it, if
you are replastering the walls, why not put up insulated PB and skim
that instead ?


---
--

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Version: 6.0.548 / Virus Database: 341 - Release Date: 05/12/2003



--
Andrew

"Andrew" wrote in message
...
In article , IMM
writes

"Christian McArdle" wrote in message
.net...
When you add an extension, modern building regulations are going
to require cavity walls and double glazing and the heat losses
in this part are going to be a lot less (could be only a quarter)
of the equivalent size of existing house.

Indeed, I've heard of cases where adding a two storey extension has
actually
resulted in reduced calculated heat losses from the house. This is
because
an uninsulated solid wall was appended by the heavily insulated 2
storey
extension, which had considerably lower heat loss than the original
wall,
despite have many times the surface area.

The old external uninsulated solid wall then becomes internal with a lot
of
thermal mass. This, once charged with heat reduces the peaks of heat
demand.
Unless the extension has a lower roof pitch than the original (using
dormer windows for the upstairs to maintain the same cill height) which
means you have a nasty cold radiator where by part of the original gable
wall is exposed but connected the rest of it which is now within the
house.

PS In all the house makeover, 'get rich quick' etc program, how come I
never hear Ms Beeny and others mentioning the magical word
'insulation' to make the property more comfortable?. Lets face it, if
you are replastering the walls, why not put up insulated PB and skim
that instead ?

Ms Beeny know anything about building? Please! She knows about kitchens
and paint colours, that's all. A well insulated house is far more
attractive to a buyer.


---
--

Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.548 / Virus Database: 341 - Release Date: 05/12/2003

"Andrew" wrote
| PS In all the house makeover, 'get rich quick' etc program,
| how come I never hear Ms Beeny and others mentioning the
| magical word 'insulation' to make the property more
| comfortable?. Lets face it, if you are replastering the
| walls, why not put up insulated PB and skim that instead ?

Because it adds to the costs and produces no corresponding increase in sale
price. This is property development, ie tart it up cheap and sell quick.
Expenditure goes on what the customer sees and will pay for, not on 'good'
things that are hidden from view. There is usually not even the requirement
of Building Regs to put in insulation, as there is with new build.

Owain

In message , lodtop
writes

Got a combination boiler,it started leaking all over the place last
night.

Our house is a small 3 bedroom end terrace - the current boiler size
is 90,000 Btu/h and the one he recommended is exactly the same size,
this is despite telling him we are extending next year and would need
a bigger boiler.

So.......any recommendations? Should I get a new boiler now (condensor
or combi) or should I get a new heat exchanger fitted as we'll be
extending next year and will have to get a new boiler anyway?

Are you sure that you would need a bigger boiler? Combi's often have
spare heating capacity as they have to have the output to heat the DHW
anyway. A 3 bed terrace probably only needs around 50,000 BTU

We have a '100,000' Btu/h combi in and extended (extra room and bigger
kitchen) 3 bed 1930's semi. The old boiler was IIRC 50-60,000 BTU. The
heating output of Combis is adjustable. ISTR that when I installed our
combi (as part of an extended CH system) I set the heating output to
somewhere in the 60-70,000 range.

So I'd want to check if I really did need a bigger boiler first - do
some heat loss calc's on the projected extended house. Myson used to
have a free heat loss calculator to download, dunno if they still do.

However, if for whatever reason you would need to change the boiler next
year then renewing the heat exchanger doesn't seem worth it, given that
it's an expensive job.
--
Chris French, Leeds

On Sun, 7 Dec 2003 23:34:48 +0000, chris French
wrote:


So I'd want to check if I really did need a bigger boiler first - do
some heat loss calc's on the projected extended house. Myson used to
have a free heat loss calculator to download, dunno if they still do.

Yes they do, but their web site is under construction at the moment
and it isn't there..

I have a copy that I can email if anybody needs it.......



However, if for whatever reason you would need to change the boiler next
year then renewing the heat exchanger doesn't seem worth it, given that
it's an expensive job.

..andy

To email, substitute .nospam with .gl

Thanks for the advice, might stick with this one and get a new heat exchanger.

Lod

"lodtop" wrote in message
om...
Thanks for the advice, might stick with this one and get a new heat
exchanger.

What make combi?

If going for a new one get a high flowrate and pay the extra. You will not
regret it.




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Cheers if you could send it to us Andy.