Central heating upgrade
 

I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Central heating upgrade
 

On 3 June, 15:29, Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. *I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient *boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

I would start by having a survey done by someone who knows something
about central heating not a cover my arse all purpose homepack surveyor

Central heating upgrade
 

In an earlier contribution to this discussion,
Rachel Holley wrote:

I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Well, you can rule out your lowest and highest extremes! g

A lot depends on whether a new boiler can easily be slotted in in place of
the existing one, or whether a lot of pipework mods will be needed. But in
ballpark figures, you should be looking somewhere between £2k and £5k -
hopefully towards the lower end of that range.

Incidentally, I see no reason not to get quotes for work on a property which
you don't yet own. Finding the likely cost of remedial work needed is all
part of the negotiating process.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Central heating upgrade
 

Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.


Thats so you can knock the price down. Its a bargaining point.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Well none of that is instantly NECESSARY.

A 1980s boiler should still be OK, and any efficiency gains need
balancing against the actual cost of a new boiler.

You are looking in the 1500-5000 range to upgrade a CH system, depending
on how far you go.

I.e. I would ALWAYS unless it was a bachelor flat, ditch a combi and put
in a mains pressure hot water tank, and a water softener, and,
depending on the layout, some form of CH zoning, even if it is only TRV
stats..

But Id put it off until the sums said it would pay back..

Central heating upgrade
 

"The Natural Philosopher" wrote in message
...
Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.


Thats so you can knock the price down. Its a bargaining point.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Well none of that is instantly NECESSARY.

A 1980s boiler should still be OK, and any efficiency gains need
balancing against the actual cost of a new boiler.

You are looking in the 1500-5000 range to upgrade a CH system, depending
on how far you go.

I.e. I would ALWAYS unless it was a bachelor flat, ditch a combi and put
in a mains pressure hot water tank, and a water softener, and,
depending on the layout, some form of CH zoning, even if it is only TRV
stats..

But Id put it off until the sums said it would pay back..

definitiely ditch the combi...

Central heating upgrade
 

In article
,
Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

Called covering their arse since they don't know. You'll probably have had
the same about the wiring and roof, etc.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

It really depends on just how well the original installation was done. If
it was state of the art at the time, a new boiler, TRVs and some simple
mods might bring it up to date. If a poor installation and badly
maintained it might need total replacement.

--
*On the seventh day He brewed beer *

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

Central heating upgrade
 

Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

If it's working then leave it as it is for the time being but as someone
else said, use the state of the heating system to get the price of the house
down.

If it has a working boiler and feed and return pipework, then spend a couple
of hundred quid getting a programmable thermostat, and fit TRV's to all the
rad's except where the main 'stat is located.

Before it get's too cold, put some central heating cleaner in the system and
run for a few days. Drain off, take off all rads and flush out with hose in
garden. Replace. Fill system, run, flush, fill, run, flush, put inhibitor
in, then fill.

That should save you a few quid in running the heating and achieve a warmer
house with few if any cold or hot spots.

Central heating upgrade
 

On 3 June, 17:44, "Davey" wrote:
Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. *I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient *boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

If it's working then leave it as it is for the time being but as someone
else said, use the state of the heating system to get the price of the house
down.

If it has a working boiler and feed and return pipework, then spend a couple
of hundred quid getting a programmable thermostat, and fit TRV's to all the
rad's except where the main 'stat is located.

Before it get's too cold, put some central heating cleaner in the system and
run for a few days. Drain off, take off all rads and flush out with hose in
garden. Replace. Fill system, run, flush, fill, run, flush, put inhibitor
in, then fill.

That should save you a few quid in running the heating and achieve a warmer
house with few if any cold or hot spots.

Is it right to say that the system could just need cleaning, controls
updated* and everything properly insulated etc?

*If it can be converted to a fully pumped system the convert it to a
"S" plan or "Y" plan maybe..

Just wanted to know because I get asked this type of question
sometimes.

Central heating upgrade
 

On Wed, 03 Jun 2009 07:29:35 -0700, Rachel Holley wrote:

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Ballpark £2500-£3000 for new boiler, TRVs & new controls, install, flush
rads etc.

--
John Stumbles -- http://yaph.co.uk

Testiculate [v.t]
To wave one's arms around while talking ********.

Central heating upgrade
 

Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

If its really 1980s then unless its a cast iron exchanger boiler, it
should be fine to leave it in service more or less indefinitely. Cast
iron exchanger boilers have terrible efficiency (50%ish) and would
need replacement, somewhere in the 1-3k region. If at the same time
you replaced the rest then a bit more. Whether you'd want to depends
on the design and condition of whats there.

IOW its datedness is not a cause for any concern... but if cast iron
then replace.


NT

Central heating upgrade
 

On Wed, 3 Jun 2009 17:44:14 +0100, Davey wrote:

If it's working then leave it as it is for the time being but as someone
else said, use the state of the heating system to get the price of the
house down.

Aye.

If it has a working boiler and feed and return pipework, then spend a
couple of hundred quid getting a programmable thermostat, and fit TRV's
to all the rad's except where the main 'stat is located.

As it's an old house with presumably little done to it. Spending a couple
of hundred quid on upping the loft insulation will save more than a
programable stat and TRV's...

Before it get's too cold, put some central heating cleaner in the system
and run for a few days. Drain off, take off all rads and flush out with
hose in garden. Replace. Fill system, run, flush, fill, run, flush, put
inhibitor in, then fill.

First step, check if the system needs all that. It might have been
maintained and/or have inhibitor already. Ask the vendors a vague question
about any work/maintenace done at the property *before* you suggest a
lowering of the price due to the work required on the heating.

--
Cheers
Dave.

Central heating upgrade
 

David wrote:
On 3 June, 17:44, "Davey" wrote:
Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

SNIP


If it's working then leave it as it is for the time being but as
someone else said, use the state of the heating system to get the
price of the house down.

If it has a working boiler and feed and return pipework, then spend
a couple of hundred quid getting a programmable thermostat, and fit
TRV's to all the rad's except where the main 'stat is located.

Before it get's too cold, put some central heating cleaner in the
system and run for a few days. Drain off, take off all rads and
flush out with hose in garden. Replace. Fill system, run, flush,
fill, run, flush, put inhibitor in, then fill.

That should save you a few quid in running the heating and achieve a
warmer house with few if any cold or hot spots.

Is it right to say that the system could just need cleaning, controls
updated* and everything properly insulated etc?

I did the above to my folks heating last year and it really improved the
heat output from the rads. They live in a 1960's bungalow with a twenty plus
year old boiler.

If you have a working boiler as a heat source, then it's still a heat source
weather it's a condensing super modern one, or an eighties job. If you can
close your eyes and feel heat from the rads, what does it matter?

Personally, I wouldn't change a working boiler for a newer more efficient
one unless the old one had poor efficiency, and I mean REALLY poor. By the
time you've got your money back on a new boiler installation it'll be
knackered and need replacing again, so you'll never catch up with making
your money back from the improved efficiency. If it's broken beyond economic
repair, then I'd swap it out.

If a new boiler saved you £200 a year on gas bills, then it'd take ten years
to make your money back on a £2k installation. Will the new condensing
boiler still be servicable in ten years?

Central heating upgrade
 

Dave Liquorice wrote:
On Wed, 3 Jun 2009 17:44:14 +0100, Davey wrote:

If it's working then leave it as it is for the time being but as
someone else said, use the state of the heating system to get the
price of the house down.

Aye.

If it has a working boiler and feed and return pipework, then spend a
couple of hundred quid getting a programmable thermostat, and fit
TRV's to all the rad's except where the main 'stat is located.

As it's an old house with presumably little done to it. Spending a
couple of hundred quid on upping the loft insulation will save more
than a programable stat and TRV's...

True nuff. But doing both would improve everything moreso :)

First step, check if the system needs all that. It might have been
maintained and/or have inhibitor already. Ask the vendors a vague
question about any work/maintenace done at the property *before* you
suggest a lowering of the price due to the work required on the
heating.

Expecting an honest answer from someone trying to sell their house would be
optimistic to say the least. They'll say "oh yeah, it's always been well
maintained" when you ask them, because they know you won't be in the house
long enough to check if it was true or horse-****. By the time you find out
the truth, it'll be too late. Hoping for the best and expecting the worst
would be best in this (and any other house sale) instance.

I live in a 8 n' 1/2 year old house and there had never been any inhibitor
in the heating. Only when I took the rads and flushed them out did I see how
much **** there was in the system from build up of deposits. If you DIY a
flushout of the rads and system from the earliest instance of buying a
house, you'll know it's history and can work from that reference point.

Central heating upgrade
 

Davey wrote:

Expecting an honest answer from someone trying to sell their house would be
optimistic to say the least. They'll say "oh yeah, it's always been well
maintained" when you ask them, because they know you won't be in the house
long enough to check if it was true or horse-****. By the time you find out
the truth, it'll be too late. Hoping for the best and expecting the worst
would be best in this (and any other house sale) instance.


Which is why its seldom worth doing more than making things LOOK as
though they have been well maintained when selling a house. People wont
pay more for things you cant prove, so why do them?

Central heating upgrade
 

On Wed, 3 Jun 2009 19:50:50 +0100, Davey wrote:

Expecting an honest answer from someone trying to sell their house would
be optimistic to say the least. They'll say "oh yeah, it's always been
well maintained" when you ask them,

A surprising number of people are honest, also ask for the last couple of
bills as proof. They are quite often available and are produced, after all
it is in their interest to show that the maintenace has taken place. In
this case it counters some of the reduction in price, hence asking all
questions (and getting the answers) before making a lower offer.

--
Cheers
Dave.

Central heating upgrade
 

On Wed, 3 Jun 2009 14:29:35 UTC, Rachel Holley
wrote:

I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Just to add to the other replies....get several quotes.

And avoid British Gas - they are incredibly expensive and (IMHO) not
that good (they just contract out).

I got three quotes for ours - new boiler and some other work. Local
(trusted) man was 1900, and another local firm 1850. BG wanted 3200!
Oh, and BG quoted for what would have been an undersized boiler.
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

Central heating upgrade
 

Rachel Holley coughed up some electrons that declared:

I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

Stop worrying - you need to make your own decisions, not base everything off
a HomeBuyers report, which to be honest is more or less worthless.

If you want to sleep soundly, then one thing you can do is to get a
Corgi/Gassafe chap round and ask for a gas safety check on the whole
system, including (and be sure to ask) a "gas tightness test" (pipes
leak?), and ask that the boiler flue and room ventilation requirements be
positively checked.

Should be around the 100-150 quid mark. Asking for a boiler service at the
same time might be an idea (give it a good clean out).

If that all passes as OK, then do what you want when you want. Run the
boiler for a year and if everything is working reliably, don't bother doing
anything, until it suits you.

As others have said, you may find you can use your money more wisely with
some more insulation or other energy saving measures.

Cheers

Tim

Central heating upgrade
 

The message

from contains these words:

If its really 1980s then unless its a cast iron exchanger boiler, it
should be fine to leave it in service more or less indefinitely. Cast
iron exchanger boilers have terrible efficiency (50%ish) and would
need replacement, somewhere in the 1-3k region. If at the same time
you replaced the rest then a bit more. Whether you'd want to depends
on the design and condition of whats there.

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

This is nonsense. The metal the heat exchanger is made of is not the
main determinant of boiler efficiency.

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s, cast
iron heat exchanger not withstanding.

The move away from cast iron may have had more to do with weight and
durability (cast iron lasts almost for ever) than increased efficiency.

--
Roger Chapman

Central heating upgrade
 

Roger wrote:
The message

from contains these words:

If its really 1980s then unless its a cast iron exchanger boiler, it
should be fine to leave it in service more or less indefinitely. Cast
iron exchanger boilers have terrible efficiency (50%ish) and would
need replacement, somewhere in the 1-3k region. If at the same time
you replaced the rest then a bit more. Whether you'd want to depends
on the design and condition of whats there.

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

This is nonsense. The metal the heat exchanger is made of is not the
main determinant of boiler efficiency.

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s, cast
iron heat exchanger not withstanding.

The move away from cast iron may have had more to do with weight and
durability (cast iron lasts almost for ever) than increased efficiency.


The metal is very relevant. Cast iron can only be cast in relatively
heavy coarse lumps, so in a given physical boiler size you dont get
anything like the same amount of finning and thus surface area with a
cast iron exchanger. That adversely affects efficiency. Then youve got
the relatively large thermal capacity of the iron casting, which again
adversely affects effieicncy on a bang-bang controlled boiler, as
almost all domestic boilers are (ie on or off rather than modulated).

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.


NT

Central heating upgrade
 

The message
from contains these words:

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

This is nonsense. The metal the heat exchanger is made of is not the
main determinant of boiler efficiency.

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s, cast
iron heat exchanger not withstanding.

The move away from cast iron may have had more to do with weight and
durability (cast iron lasts almost for ever) than increased efficiency.


The metal is very relevant. Cast iron can only be cast in relatively
heavy coarse lumps, so in a given physical boiler size you dont get
anything like the same amount of finning and thus surface area with a
cast iron exchanger. That adversely affects efficiency. Then youve got
the relatively large thermal capacity of the iron casting, which again
adversely affects effieicncy on a bang-bang controlled boiler, as
almost all domestic boilers are (ie on or off rather than modulated).

You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate. You even played the typical
Dribble trick of inserting an additional qualification to bolster a weak
argument. Take out the "a given physical boiler size" and you can match
the surface area.

What could make a significant difference but which you fail to mention
is the difference in thermal conductivity between Aluminium and cast
iron but there again that is more a question of size constraints than
any inherent unsuitability of cast iron.

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Now why would the op be disappointed to find that the boiler in question
has say a 70% efficiency rather than the 50ish% that you said was his
lot.

--
Roger Chapman

Central heating upgrade
 

On Wed, 3 Jun 2009 07:33:35 -0700 (PDT), cynic
wrote:

On 3 June, 15:29, Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. *I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient *boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

I would start by having a survey done by someone who knows something
about central heating not a cover my arse all purpose homepack surveyor
Had mine replaced about 9 months ago. 35 (+) year old Potterton cast
iron boiler supplying 9 rads and indirect cylinder to give you an idea
of the size. Had the new boiler, a Worcester Bosch Greenstar 24i,
installed in a new location about 8ft above where the old one was, so
some pipework changes needed. New flue out of the roof, new pump,
programmer, valves, and condensate pump. System power flushed the
filled with inhibitor. Total cost £3.6K, took 3.5 days (about 6-7 man
days).
Really struggled to find someone to do it, they seem to cherry pick
the easy jobs.
HTH
David

Central heating upgrade
 

On Thu, 4 Jun 2009, Roger wrote:

The message
from contains these words:

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s, cast
iron heat exchanger not withstanding.

The metal is very relevant. Cast iron can only be cast in relatively
heavy coarse lumps, so in a given physical boiler size you dont get
anything like the same amount of finning and thus surface area with a
cast iron exchanger. That adversely affects efficiency. Then youve got
the relatively large thermal capacity of the iron casting, which again
adversely affects effieicncy on a bang-bang controlled boiler, as
almost all domestic boilers are (ie on or off rather than modulated).

You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate. You even played the typical
Dribble trick of inserting an additional qualification to bolster a weak
argument. Take out the "a given physical boiler size" and you can match
the surface area.

What could make a significant difference but which you fail to mention
is the difference in thermal conductivity between Aluminium and cast
iron but there again that is more a question of size constraints than
any inherent unsuitability of cast iron.

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Now why would the op be disappointed to find that the boiler in question
has say a 70% efficiency rather than the 50ish% that you said was his
lot.

Indeed. My 25-yy Potterton Netaheat is 68% efficient, says sedbuk.
Thanks for the link Roger!

I personally wish it lasts another 50 years, if at all possible,
though I would love to move my boiler to the attic (not recommended;
flue availability and it may well break in the process). Mr Friendly
Local Gasman gave it its annual service last month and said it's in
really good nick. That's the way (a-ha a-ha).

Kostas

Central heating upgrade
 

Roger wrote:
The message
from contains these words:

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

This is nonsense. The metal the heat exchanger is made of is not the
main determinant of boiler efficiency.

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s, cast
iron heat exchanger not withstanding.

The move away from cast iron may have had more to do with weight and
durability (cast iron lasts almost for ever) than increased efficiency.


The metal is very relevant. Cast iron can only be cast in relatively
heavy coarse lumps, so in a given physical boiler size you dont get
anything like the same amount of finning and thus surface area with a
cast iron exchanger. That adversely affects efficiency. Then youve got
the relatively large thermal capacity of the iron casting, which again
adversely affects effieicncy on a bang-bang controlled boiler, as
almost all domestic boilers are (ie on or off rather than modulated).

You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

You even played the typical
Dribble trick of inserting an additional qualification to bolster a weak
argument. Take out the "a given physical boiler size" and you can match
the surface area.

in the real world boilers are of limited size


What could make a significant difference but which you fail to mention
is the difference in thermal conductivity between Aluminium and cast
iron

less significant that the fin design

but there again that is more a question of size constraints than
any inherent unsuitability of cast iron.

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Now why would the op be disappointed to find that the boiler in question
has say a 70% efficiency rather than the 50ish% that you said was his
lot.

comparing an old cast iron job to a modern boiler is liable to lead to
decision to replace it. That is the disappointment.


NT

Central heating upgrade
 

The message

from contains these words:

You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

So you say but like Dribble you don't stop to think where the heat
actually goes and what effect it has on the in house environment. And I
would take issue with you on the amount of heat involved when the
thermostat stops calling for heat . Would you care to produce some real
figures to back up your claim?

You even played the typical
Dribble trick of inserting an additional qualification to bolster a weak
argument. Take out the "a given physical boiler size" and you can match
the surface area.

in the real world boilers are of limited size

But by no means all the same size.

What could make a significant difference but which you fail to mention
is the difference in thermal conductivity between Aluminium and cast
iron

less significant that the fin design

If you think that then there really is no hope for you.

but there again that is more a question of size constraints than
any inherent unsuitability of cast iron.

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Now why would the op be disappointed to find that the boiler in question
has say a 70% efficiency rather than the 50ish% that you said was his
lot.

comparing an old cast iron job to a modern boiler is liable to lead to
decision to replace it. That is the disappointment.

Not to anyone who can add 2 and 2 together and get 4 rather than the
square root of minus one. In most cases the economics of having a boiler
in good working order replaced are dubious at best and not to be
contemplated if the replacement cost has to be borrowed.

--
Roger Chapman

Central heating upgrade
 

In article
,
wrote:
You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

Not if you fit a pump over run so that energy it transferred to either the
heating or hot water.

--
*A bicycle can't stand alone because it's two tyred.*

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

Central heating upgrade
 

"Roger" wrote in message
k...
The message

from contains these words:

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

This is nonsense. The metal the heat exchanger is made of is not the
main determinant of boiler efficiency.

If you know what the boiler model is sedbuk.com will probably tell you
how efficient it is. They acknowledge a class of old boiler with an
efficiency as low as 55% but they do not appear to list any gas fired
boilers at less than 65% and features such as electronic ignition (no
permanent pilot light) and fan assisted flue (both available before the
end of the 80s) could push the efficiency up to the mid - high 70s,
cast
iron heat exchanger not withstanding.

The move away from cast iron may have had more to do with weight and
durability (cast iron lasts almost for ever) than increased efficiency.

The metal is very relevant. Cast iron can only be cast in relatively
heavy coarse lumps, so in a given physical boiler size you dont get
anything like the same amount of finning and thus surface area with a
cast iron exchanger. That adversely affects efficiency. Then youve got
the relatively large thermal capacity of the iron casting, which again
adversely affects effieicncy on a bang-bang controlled boiler, as
almost all domestic boilers are (ie on or off rather than modulated).

You

This man is a barking mad plantpot. Do not take any notice of him.

Central heating upgrade
 

"Kostas Kavoussanakis" wrote in message
. rq.np.hx...

Indeed. My 25-yy Potterton Netaheat is 68% efficient,

Only when new and working well designed and efficient system. It is more
like 55%.

Central heating upgrade
 

"Roger" wrote in message
k...

comparing an old cast iron job to a modern boiler is liable to lead to
decision to replace it. That is the disappointment.

Not to anyone who can add 2 and 2 together

This amateur is barking mad and should be ignored.

Central heating upgrade
 

wrote in message
...
Roger wrote:
The message


The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

Total tripe!

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

Correct!

Central heating upgrade
 

wrote in message
...

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Very true!

Central heating upgrade
 

"Dave Plowman (News)" wrote in message
...
In article
,
wrote:
You are sounding more and more like Dribble every day. The difference
in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

Not if you fit a pump over run so that energy it transferred to either the
heating or hot water.

Mine has over run, however as it is fully zoned it can't dump the heat into
any of the zones.
I made it dump it into the airing cupboard via the bypass pipe.

Central heating upgrade
 

In article ,
dennis@home wrote:


"Dave Plowman (News)" wrote in message
...
In article
,
wrote:
You are sounding more and more like Dribble every day. The
difference in efficiency is only marginal. The larger thermal
capacity may even be an advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

Not if you fit a pump over run so that energy it transferred to either
the heating or hot water.

Mine has over run, however as it is fully zoned it can't dump the heat
into any of the zones. I made it dump it into the airing cupboard via
the bypass pipe.

It will dump most of its excess heat into the room it's in anyway - which
may or may not be a good thing. Mine is in the bathroom which can rarely
be too warm. If it's situated outside the house it could well be just
wasted.
I do wonder about these quoted efficiencies. I recently changed from an
ancient cast iron type to a state of the art condenser - and although
there have been worthwhile savings the gas usage isn't in direct
proportion to the quoted efficiency increase - although I'll need a bit
longer to get a better average.
I'd guess they're a bit like official car MPG figures - a
lab. measurement which can't take real world usage into account.

--
*El nino made me do it

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

Central heating upgrade
 

The message
from "Dave Plowman (News)" contains these words:

I do wonder about these quoted efficiencies. I recently changed from an
ancient cast iron type to a state of the art condenser - and although
there have been worthwhile savings the gas usage isn't in direct
proportion to the quoted efficiency increase - although I'll need a bit
longer to get a better average.
I'd guess they're a bit like official car MPG figures - a
lab. measurement which can't take real world usage into account.

Can you monitor your return temperature?

Condensing can give you up to an extra 10% but you won't get any of that
if the return is above 54C and you may never get the return low enough
to give you the full measure as that temperature is well below most
peoples comfort zone.

--
Roger Chapman

Central heating upgrade
 

The message
from "Doctor Drivel" contains:

Absolutely nothing of any consequence.

As usual Dribble has nothing positive to add to the discussion so he
resorts to his very limited range of insults.


Meanwhile something for the Dribbles of this world to get their teeth into:

"Condensing boiler technology is evolving rapidly. A fully condensing
boiler with a cast-iron heat exchanger has been introduced in the United
States. It deals with the corrosive nature of the condensate produced in
it by increasing the wall thickness of the heat exchanger sufficient to
deliver an expected residential life of four to six decades and by
discouraging the conditions that accelerate corrosion."

If Dribble and his pal are to be believed that would be a condensing
boiler with an efficiency in the region of 65% at best. :-)

--
Roger Chapman

Central heating upgrade
 

Roger wrote:
The message

from contains these words:

You are sounding more and more like Dribble every day. The difference in
efficiency is only marginal. The larger thermal capacity may even be an
advantage in a boiler that doesn't modulate.

It isnt, much of the heat stored in the exchanger is wasted at each
switch off.

So you say but like Dribble you don't stop to think where the heat
actually goes and what effect it has on the in house environment.

incorrect again. The heat goes partly into the water in the exchanger,
which is not flowing, and partly up the flue to outdoors. The heat
that has gone into the water then has many minutes in which to cool
off and give its heat to the outdoors. So its almost all lost.

Effect on in house environment is insignificant. Exchanger heat is not
lost to indoors.


And I
would take issue with you on the amount of heat involved when the
thermostat stops calling for heat . Would you care to produce some real
figures to back up your claim?

How much heat is stored in the iron depends on the boiler design. The
point remains valid regardless of how large it is.


You even played the typical
Dribble trick of inserting an additional qualification to bolster a weak
argument. Take out the "a given physical boiler size" and you can match
the surface area.

in the real world boilers are of limited size

But by no means all the same size.

and?

What could make a significant difference but which you fail to mention
is the difference in thermal conductivity between Aluminium and cast
iron

less significant that the fin design

If you think that then there really is no hope for you.

no valid point then

but there again that is more a question of size constraints than
any inherent unsuitability of cast iron.

You can look up the efficiency of your boiler model, but if the
exchanger is cast iron, prepare to be disappointed.

Now why would the op be disappointed to find that the boiler in question
has say a 70% efficiency rather than the 50ish% that you said was his
lot.

comparing an old cast iron job to a modern boiler is liable to lead to
decision to replace it. That is the disappointment.

Not to anyone who can add 2 and 2 together and get 4 rather than the
square root of minus one. In most cases the economics of having a boiler
in good working order replaced are dubious at best

in many cases, but clearly not in all cases. Replacing an iron boiler
running at 55% with a new one at 80-90% makes a big saving, justifying
quite a lot of boiler cost.

Lets take an example. Say an 85% boiler costs £600 a year in gas, so a
55% one would cost 600x .85/.55 = £927 pa, thus there is a £327 pa
fuel saving from replacement. If a new boiler costs £1500, that's a
21.8% pa return. Over a 20 year life it would save £6,500 on fuel. We
could subtract an arbitrary £500 in extra maintenance costs and the
£1500 buy & install cost to give a £4,500 benefit. But not worth it
you think.

and not to be
contemplated if the replacement cost has to be borrowed.


NT

Central heating upgrade
 

Roger wrote:
The message
from "Doctor Drivel" contains:

Absolutely nothing of any consequence.

As usual Dribble has nothing positive to add to the discussion so he
resorts to his very limited range of insults.


Meanwhile something for the Dribbles of this world to get their teeth into:

"Condensing boiler technology is evolving rapidly. A fully condensing
boiler with a cast-iron heat exchanger has been introduced in the United
States. It deals with the corrosive nature of the condensate produced in
it by increasing the wall thickness of the heat exchanger sufficient to
deliver an expected residential life of four to six decades and by
discouraging the conditions that accelerate corrosion."

If Dribble and his pal are to be believed that would be a condensing
boiler with an efficiency in the region of 65% at best. :-)

No-one has made such a claim. We were discussing old iron exchanger
boilers decades old. You and facts eh.


NT

Central heating upgrade
 

Tim S wrote:
Rachel Holley coughed up some electrons that declared:

I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us �20, �2000 or �2000000?

Stop worrying - you need to make your own decisions, not base everything off
a HomeBuyers report, which to be honest is more or less worthless.

If you want to sleep soundly, then one thing you can do is to get a
Corgi/Gassafe chap round and ask for a gas safety check on the whole
system, including (and be sure to ask) a "gas tightness test" (pipes
leak?), and ask that the boiler flue and room ventilation requirements be
positively checked.

Should be around the 100-150 quid mark. Asking for a boiler service at the
same time might be an idea (give it a good clean out).

If that all passes as OK, then do what you want when you want. Run the
boiler for a year and if everything is working reliably, don't bother doing
anything, until it suits you.

or get a landlords safety certificate for £50.


As others have said, you may find you can use your money more wisely with
some more insulation or other energy saving measures.

Cheers

Tim

yup


NT

Central heating upgrade
 

Central heating upgrade
 

In article ,
Roger wrote:
The message
from "Dave Plowman (News)" contains these words:

I do wonder about these quoted efficiencies. I recently changed from an
ancient cast iron type to a state of the art condenser - and although
there have been worthwhile savings the gas usage isn't in direct
proportion to the quoted efficiency increase - although I'll need a bit
longer to get a better average.
I'd guess they're a bit like official car MPG figures - a
lab. measurement which can't take real world usage into account.

Can you monitor your return temperature?

Condensing can give you up to an extra 10% but you won't get any of that
if the return is above 54C and you may never get the return low enough
to give you the full measure as that temperature is well below most
peoples comfort zone.

The boiler spends pretty well all its time in condensing mode judging by
the plume from the exhaust.

--
*To err is human. To forgive is against company policy.

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

Central heating upgrade
 

On Jun 3, 6:51*pm, wrote:
Rachel Holley wrote:
I'm in the process of buying a late 60s semi, and the homebuyer's
report has flagged up that the central heating system is old and
hasn't been updated for a long time, and will probably need
substantial repairs soon and/or replacing with a newer efficient
system.

This is our first house, so we're not really sure what kind of costs
that will entail. We can't really ask a plumber to come and give us
quotes because we're not in the house yet. *I'm guessing the current
boiler is roughly 1980s, with a hot water tank. We would probably want
to get a nice efficient *boiler (Condensing?), plus a new main
thermostat and thermostatic radiator valves put on the existing
radiators.

Does anyone have any idea what the likely cost might be? Just a
ballpark figure, like will it cost us £20, £2000 or £2000000?

If its really 1980s then unless its a cast iron exchanger boiler, it
should be fine to leave it in service more or less indefinitely. Cast
iron exchanger boilers have terrible efficiency (50%ish) and would
need replacement, somewhere in the 1-3k region. If at the same time
you replaced the rest then a bit more. Whether you'd want to depends
on the design and condition of whats there.

IOW its datedness is not a cause for any concern... but if cast iron
then replace.

NT

We bought our house in 2003. It had just had a new what I assume was
cast iron floor mounted boiler to replace the old one because "it
fitted in the same space, etc". It broke my heart to have to dump
something so new in order to refit the rest of the kitchen properly.

MBQ