I need to replace the vented indirect DHW cylinder in a ground floor 2
bed flat, heated by a Baxi back boiler. I considered changing to a combi
instead but the current boiler appears to be going well and replacing it
with a combi would be an extreme pain because of the layout of the flat
- so I plan to just replace the cylinder.
There seems no reason to change the primary system so it will stay
vented. It would be good to get rid of the DHW header tank because of
access difficulties so I'm trying to decide between a thermal store or
an unvented cylinder.

Can anyone recommend a small store or unvented cylinder? who has the
best prices?

Dave

"Dave" wrote in message
...

I need to replace the vented indirect DHW cylinder in a ground floor 2 bed
flat, heated by a Baxi back boiler. I considered changing to a combi
instead but the current boiler appears to be going well and replacing it
with a combi would be an extreme pain because of the layout of the flat -
so I plan to just replace the cylinder.
There seems no reason to change the primary system so it will stay vented.
It would be good to get rid of the DHW header tank because of access
difficulties so I'm trying to decide between a thermal store or an
unvented cylinder.

Can anyone recommend a small store or unvented cylinder? who has the best
prices?

Forget and unvented cylinder. You need to have a BBA approved plumber to so
it. You also need an annual service. A 'heat bank' will excellent
flowrates. Heat banks have plate heat exchangers.

Look at:

http://www.newarkcyl.freeserve.co.uk (a cheap thermal stores and will make
to order)
http://www.mcdonald-engineers.com (Thermal stores and will make to order)
http://www.elsonho****er.co.uk/ (make square storage vessels, inc thermal
stores)
http://www.heatweb.com (make heat banks and storage vessels to size)
http://www.albion-online.co.uk (make thermal stores and stoarge vessels)
http://www.range-cylinders.co.uk (make cylindrical heat banks and storage
vessels. Will make to order)
http://www.gledhill.net (make heat banks (thermal stores they call them) and
storage vessels. Expensive but v good)
http://www.telford-group.com make cylindrical thermal stores and storage
vessels
http://www.chelmerheating.co.uk (make cylindrical thermal stores. Expensive)
http://www.rcmgroup.co.uk/ (make thermal stores and cylinders)

On Fri, 06 Jan 2006 19:09:01 +0000, Doctor Drivel wrote:


"Dave" wrote in message
...

I need to replace the vented indirect DHW cylinder in a ground floor 2 bed
flat, heated by a Baxi back boiler. I considered changing to a combi
instead but the current boiler appears to be going well and replacing it
with a combi would be an extreme pain because of the layout of the flat -
so I plan to just replace the cylinder.

Given that either and unvented cylinder or a thermal store will cost you
more than a decent condensing combi and that your back boiler will
eventually have to go I'd be inclined to reconsider changing the boiler.
You'd also gain the space used by a cylinder.


There seems no reason to change the primary system so it will stay
vented. It would be good to get rid of the DHW header tank because of
access difficulties so I'm trying to decide between a thermal store or
an unvented cylinder.

Can anyone recommend a small store or unvented cylinder? who has the
best prices?

Forget and unvented cylinder. You need to have a BBA approved plumber
to so it. You also need an annual service. A 'heat bank' will excellent
flowrates. Heat banks have plate heat exchangers.

Last time I looked one of the suppliers (forget which, but I think it was
one of the ones Dr D mentioned) did one with a coil-in-the-cylinder heat
exchanger. ISTR that plate types are supposed to be better in hard water
areas, but they do have another pump and flow switch to go wrong (as all
mechanical things do at some time or other). The coil-in-the-cylinder heat
exchanger has no moving parts.

There are also options of having the thermal store supply the CH as well
as HW, which gives a faster heat from cold for the radiators at the
expense of having to have a larger store for a given hot water capacity.

You should be able to DIY a thermal store system with off-the-shelf parts,
though I haven't tried this (yet ...)

"John Stumbles" wrote in message
news
On Fri, 06 Jan 2006 19:09:01 +0000, Doctor Drivel wrote:


"Dave" wrote in message
...

I need to replace the vented indirect DHW cylinder in a ground floor 2
bed
flat, heated by a Baxi back boiler. I considered changing to a combi
instead but the current boiler appears to be going well and replacing it
with a combi would be an extreme pain because of the layout of the
flat -
so I plan to just replace the cylinder.

Given that either and unvented cylinder or a thermal store will cost you
more than a decent condensing combi and that your back boiler will
eventually have to go I'd be inclined to reconsider changing the boiler.
You'd also gain the space used by a cylinder.


There seems no reason to change the primary system so it will stay
vented. It would be good to get rid of the DHW header tank because of
access difficulties so I'm trying to decide between a thermal store or
an unvented cylinder.

Can anyone recommend a small store or unvented cylinder? who has the
best prices?

Forget and unvented cylinder. You need to have a BBA approved plumber
to so it. You also need an annual service. A 'heat bank' will excellent
flowrates. Heat banks have plate heat exchangers.

Last time I looked one of the suppliers (forget which, but I think it was
one of the ones Dr D mentioned) did one with a coil-in-the-cylinder heat
exchanger.

Newark do a cheap thermal store. MacDonald are not that bad either. RCM are
not expensive either.

John Stumbles wrote:

.... snipped

Given that either and unvented cylinder or a thermal store will cost you
more than a decent condensing combi and that your back boiler will
eventually have to go I'd be inclined to reconsider changing the boiler.
You'd also gain the space used by a cylinder.

.... snipped

The only place to fit a combi would be in the airing cupboard (in the
centre of the flat, next to the old chimney breast) but then it would
need to use the current back boiler flue - are there any combis that can
do this?

Dave

Doctor Drivel wrote:

"Dave" wrote in message
...

I need to replace the vented indirect DHW cylinder in a ground floor 2
bed flat, heated by a Baxi back boiler. I considered changing to a
combi instead but the current boiler appears to be going well and
replacing it with a combi would be an extreme pain because of the
layout of the flat - so I plan to just replace the cylinder.
There seems no reason to change the primary system so it will stay
vented. It would be good to get rid of the DHW header tank because of
access difficulties so I'm trying to decide between a thermal store or
an unvented cylinder.

Can anyone recommend a small store or unvented cylinder? who has the
best prices?


Forget and unvented cylinder. You need to have a BBA approved plumber
to so it. You also need an annual service. A 'heat bank' will excellent
flowrates. Heat banks have plate heat exchangers.

Look at:

http://www.newarkcyl.freeserve.co.uk (a cheap thermal stores and will
make to order)
http://www.mcdonald-engineers.com (Thermal stores and will make to order)
http://www.elsonho****er.co.uk/ (make square storage vessels, inc
thermal stores)
http://www.heatweb.com (make heat banks and storage vessels to size)
http://www.albion-online.co.uk (make thermal stores and stoarge vessels)
http://www.range-cylinders.co.uk (make cylindrical heat banks and
storage vessels. Will make to order)
http://www.gledhill.net (make heat banks (thermal stores they call them)
and storage vessels. Expensive but v good)
http://www.telford-group.com make cylindrical thermal stores and storage
vessels
http://www.chelmerheating.co.uk (make cylindrical thermal stores.
Expensive)
http://www.rcmgroup.co.uk/ (make thermal stores and cylinders)


Thanks for the long list of links, probably saved me a lot of time on
google! (I tried dealing with DPS before, they were helpful but had
leadtimes that were too long).
If I opted for unvented I was going to get someone to "sign it off"
afterwards.

John's comments have made me think again about a Combi but the locations
a
- In the airing cupboard: next to chimney so would need to use existing
flue, nowhere for condensate to go other than a 3m run through the
lounge to the outside.
- In the kitchen: would need to be in a structural larder (heat),
difficult access, unlikely to get clearance distances from doors/windows
- In the lounge: would need to run pipes through the lounge, difficult
to get clearance distances from doors/windows, noise, visible wart on
the wall.

What's the usual solution in old small flats that currently have back
boilers?

Dave

"Dave" wrote in message
...

Thanks for the long list of links, probably saved me a lot of time on
google! (I tried dealing with DPS before, they were helpful but had
leadtimes that were too long).

How long? They do a lot of custom stuff for UFH and the likes. They do have
some standard products though, which should be quicker to source.

If I opted for unvented I was going to get someone to "sign it off"
afterwards.

Avoid unvented as they require an annual service. If no service and a water
leak insurance job the company will not pay up. Something which many people
overlook. Low pressure heat banks and thermals stores cannot explode, and
no matter how remote an unvented can.

John's comments have made me think again about a Combi but the locations
a

- In the airing cupboard: next to chimney so would need to use existing
flue, nowhere for condensate to go other than a 3m run through the lounge
to the outside.

Sounds OK. Can you get to a loft above the cupboard? Top flat? If so then
the flue can be run through the loft and out of a gable end. Modern boilers
have very flexible flue systems that can go 30 metres or so. The flue can
be run through the chimney and may be the best method. A condensing boiler
may be exempt. Although many have integral condensate pumps. These can be
bought separately. When full it pumps condensate away down a long pipe. So,
not really a problem.

- In the kitchen: would need to be in a structural larder (heat),
difficult access, unlikely to get clearance distances from doors/windows

- In the lounge: would need to run pipes through the lounge, difficult to
get clearance distances from doors/windows, noise, visible wart on the
wall.

What's the usual solution in old small flats that currently have back
boilers?

Fit a combi :-) The airing cupboard looks the best bet. Break into the
breast and take it from there. Look at high flow combis.

Doctor Drivel wrote:

"Dave" wrote in message
...

.... snipped

John's comments have made me think again about a Combi but the
locations a

- In the airing cupboard: next to chimney so would need to use
existing flue, nowhere for condensate to go other than a 3m run
through the lounge to the outside.


Sounds OK. Can you get to a loft above the cupboard? Top flat? If so
then the flue can be run through the loft and out of a gable end.
Modern boilers have very flexible flue systems that can go 30 metres or
so. The flue can be run through the chimney and may be the best
method. A condensing boiler may be exempt. Although many have integral
condensate pumps. These can be bought separately. When full it pumps
condensate away down a long pipe. So, not really a problem.

.... snipped

Fit a combi :-) The airing cupboard looks the best bet. Break into the
breast and take it from there. Look at high flow combis.


It's a ground floor flat with an un-cooperative "person" in the flat
above, so the flue would need to go up/down the chimney; sounds like a
bit of a bu&&er.
"Break into the breast" reminds me of my youth - the memories make me
think of DIY ;-)

Any suggestions for combis? All I know is to avoid the Suprima.

Dave