Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have
suggested a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

TIA

Mike

On Tue, 08 Jul 2008 19:34:10 +0100, Mike wrote:

Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have
suggested a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

Personally I think that's a fine choice, but then I've fitted practically
nothing but Worcester Greenstars since condensing boilers became
mandatory[1]. I tend to fit the 24i Junior combis, even when a system
boiler might otherwise be indicated (the combis are actually cheaper than
the system models, even though the latter are the combi with some bits
*left out*!

The ri you've been recommended is the heating-only model and it sounds as
if your installer is planning to keep your system vented, with a header
tank in the attic. Ho hum, I usually convert to sealed - I suggest you
check out Ed's Sealed CH FAQ
http://www.makewrite.demon.co.uk/SealedCH.html for discussion of the pros
and cons.

My only query would be the choice of a *24* ri. 24kW is a *lot* of power
for heating only (though the bottom of the range for a combi, where much
more heat is needed to provide hot water instantaneously). I'd be asking
why? Do you have a poorly insulated mansion? Has your heating engineer
done the boiler-sizing calculations? (See
http://wiki.diyfaq.org.uk/index.php?...requir ements
or go to Heat Requirements section of
http://wiki.diyfaq.org.uk/index.php?...eating_Design). Your
engineer is probably going to have to upgrade the gas pipe to the boiler
to accomodate the extra power, and if your house really needs that much
power I'd consider putting in the combi (which would mean converting to a
sealed system) to give you a mains pressure instantaneous hot water output
for showers, even if you keep your hot water cylinder. And then I'd ask
what benefit you get from keeping the cylinder - but that's another
question - see http://wiki.diyfaq.org.uk/index.php?..._Water_Systems



[1] to a first approximation

--
John Stumbles

Procrastinate now!

Thanks John

Stevenson installed the original system. I doubt if they have done any
recalculation. But I will query the size of the boiler.

Cheers

Richard (on behalf of his aged father who is a little new to the idea of
NGs!)





John Stumbles wrote:
On Tue, 08 Jul 2008 19:34:10 +0100, Mike wrote:

Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have
suggested a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

Personally I think that's a fine choice, but then I've fitted practically
nothing but Worcester Greenstars since condensing boilers became
mandatory[1]. I tend to fit the 24i Junior combis, even when a system
boiler might otherwise be indicated (the combis are actually cheaper than
the system models, even though the latter are the combi with some bits
*left out*!

The ri you've been recommended is the heating-only model and it sounds as
if your installer is planning to keep your system vented, with a header
tank in the attic. Ho hum, I usually convert to sealed - I suggest you
check out Ed's Sealed CH FAQ
http://www.makewrite.demon.co.uk/SealedCH.html for discussion of the pros
and cons.

My only query would be the choice of a *24* ri. 24kW is a *lot* of power
for heating only (though the bottom of the range for a combi, where much
more heat is needed to provide hot water instantaneously). I'd be asking
why? Do you have a poorly insulated mansion? Has your heating engineer
done the boiler-sizing calculations? (See
http://wiki.diyfaq.org.uk/index.php?...requir ements
or go to Heat Requirements section of
http://wiki.diyfaq.org.uk/index.php?...eating_Design). Your
engineer is probably going to have to upgrade the gas pipe to the boiler
to accomodate the extra power, and if your house really needs that much
power I'd consider putting in the combi (which would mean converting to a
sealed system) to give you a mains pressure instantaneous hot water output
for showers, even if you keep your hot water cylinder. And then I'd ask
what benefit you get from keeping the cylinder - but that's another
question - see http://wiki.diyfaq.org.uk/index.php?..._Water_Systems



[1] to a first approximation

Sorry. I should have said that they are keeping the system vented

Richard (Mike!)

John Stumbles wrote:
On Tue, 08 Jul 2008 19:34:10 +0100, Mike wrote:

Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have
suggested a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

Personally I think that's a fine choice, but then I've fitted practically
nothing but Worcester Greenstars since condensing boilers became
mandatory[1]. I tend to fit the 24i Junior combis, even when a system
boiler might otherwise be indicated (the combis are actually cheaper than
the system models, even though the latter are the combi with some bits
*left out*!

The ri you've been recommended is the heating-only model and it sounds as
if your installer is planning to keep your system vented, with a header
tank in the attic. Ho hum, I usually convert to sealed - I suggest you
check out Ed's Sealed CH FAQ
http://www.makewrite.demon.co.uk/SealedCH.html for discussion of the pros
and cons.

My only query would be the choice of a *24* ri. 24kW is a *lot* of power
for heating only (though the bottom of the range for a combi, where much
more heat is needed to provide hot water instantaneously). I'd be asking
why? Do you have a poorly insulated mansion? Has your heating engineer
done the boiler-sizing calculations? (See
http://wiki.diyfaq.org.uk/index.php?...requir ements
or go to Heat Requirements section of
http://wiki.diyfaq.org.uk/index.php?...eating_Design). Your
engineer is probably going to have to upgrade the gas pipe to the boiler
to accomodate the extra power, and if your house really needs that much
power I'd consider putting in the combi (which would mean converting to a
sealed system) to give you a mains pressure instantaneous hot water output
for showers, even if you keep your hot water cylinder. And then I'd ask
what benefit you get from keeping the cylinder - but that's another
question - see http://wiki.diyfaq.org.uk/index.php?..._Water_Systems



[1] to a first approximation

"Mike" wrote in message
...
Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have suggested
a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

TIA

WB seem to be universally recommended. I know someone who runs a heating
firm and it's what he puts in his own place.

"Mike" wrote

Forgive the question if it has been answered many times before, but I am
new to this NG.

I am planning to replace my ageing Potterton boiler and have received a
quote from the plumber (Stevenson) who installed it. They have suggested
a Worcester Bosch Greenstar 24ri.

Any thoughts or views on this choice of boiler would be welcome.

TIA

Mike

Hi Mike

I had my heating overhauled 18 months ago. The DIY bit was that I
thoroughly researched all elements with the help of this group and specified
all aspects of the work. Also I had battled for 2 years before this,
improving the existing system, replacing rads and eliminating pump-over etc.

Largely on the recommendation of this group I also fitted the WB 24Ri.

I have a 4 bed detached (a bit higgledy piggledy) 1970s place - not too well
insulated yet .

Doing a detailed heat loss study I arrived at ~ 16Kw for space heating.
Conservatively adding 20% for pipe losses and a further 3Kw for the HW
cylinder gave 20Kw.
So, as a worst of worst cases I could justify the 24Kw non-combi boiler
rating.

Obviously you will be more interested in the general performance of the
unit.

The only 2 issues I have had so far a

Noise - this is the first fan assisted boiler I have experienced, so the
general operational noise was a bit of a surprise.
Also, some of the panels (particularly the bottom tray) are a loose type
fit, so some annoying vibrations have had to be silenced.

Overheat - this is nothing to do with the boiler per se. The installers did
not set up the by-pass valve properly, so it never actually by-passed. This
led to extended over-running of the boiler and the blue alarm light flashing
(until I found the problem).


At the time of install, I also had the heating zoned to separate upstairs
and down to make it more controllable. Still haven't analysed bills to see
how much gas this is actually saving!

HTH

Phil

Noise - this is the first fan assisted boiler I have experienced, so the
general operational noise was a bit of a surprise.

The 241 junior is certainly noisy. We've sort of got used to it now but
the high pitch of the fan was a bit of a shock. The cat didn't like it
either.

Also, some of the panels (particularly the bottom tray) are a loose type
fit, so some annoying vibrations have had to be silenced.

The case isn't particularly well anchored, and I haven't found any way
to stop the vibration .

The other annoying thing is that it has to deliver several litres of
cold water before the burner lights up. Very frustrating if you just
want to top up a bowl of hot water.

I expect these faults are common to all newer combis though

In article ,
TheScullster wrote:
Noise - this is the first fan assisted boiler I have experienced, so the
general operational noise was a bit of a surprise.
Also, some of the panels (particularly the bottom tray) are a loose type
fit, so some annoying vibrations have had to be silenced.

Perhaps you should have looked at the Viessmann Vitodens 200. I reckon
it's no more noisy than just the burner was on my old Potterton. The
casing has sound deadening panels. The only time you really hear it is
when it runs the fan at boost IIRC to vent the burner enclosure when first
firing. Of course it's expensive - but then it's not something you replace
every other year. Hopefully.

--
*When cheese gets it's picture taken, what does it say?

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

Surely not the case when used with a separate H/W tank? It is to be
installed as a replacement in a conventional vented system with H/W
tank and rads. Not as a combi boiler.

Richard

On 9 Jul, 10:12, stuart noble wrote:


The other annoying thing is that it has to deliver several litres of
cold water before the burner lights up. Very frustrating if you just
want to top up a bowl of hot water.