I currently have a baxi bermuda 551 back boiler central heating / hot
water system. It has a gas fire on the front
which is no longer used.

When I turned on the central heating - it's been off since last winter
- the there was no characteristic gush of water surging round the
system and the radiators don't work, apart from one in the back bedroom.

I bled the radiators, checked the valves on the thermostatic radiator
controls weren't stuck, but still no joy.

After looking at the boiler and reading some previous posts, I am coming
round to the idea that the pump is not working. The boiler still heats
water for the hot water system but it isn't coming on and staying on for
any period of time as it usually did when the central heating was on. I
can't quite work out why the back bedroom radiator is working ok, unless
water is reaching it via the ho****er system.

* How easy / expensive is it likely to be to replace the pump on this
'antique' boiler (getting someone qualified to do it that is)

* If I replace the back boiler, could I use a combi boiler but basically
keep the same hot water/ central heating setup. The back boiler
currenly heats water in a hot water tank in the airing cupboard.

* Are there any reasons other than aesthetic why I can't put a combi
boiler on the fire place using the chimney as a flue. i.e need to be
certain height above ground, thereby minimising changes in the plumbing
which is all currently situated there.

* If I went for a condensing boiler, other than finding a way to run off
the condensate, could this be situated on the fire place as above.

many thanks
angus

On Tue, 08 Nov 2005 17:07:47 GMT, angusclaydon
wrote:

I currently have a baxi bermuda 551 back boiler central heating / hot
water system. It has a gas fire on the front
which is no longer used.

When I turned on the central heating - it's been off since last winter
- the there was no characteristic gush of water surging round the
system and the radiators don't work, apart from one in the back bedroom.

I bled the radiators, checked the valves on the thermostatic radiator
controls weren't stuck, but still no joy.

After looking at the boiler and reading some previous posts, I am coming
round to the idea that the pump is not working. The boiler still heats
water for the hot water system but it isn't coming on and staying on for
any period of time as it usually did when the central heating was on. I
can't quite work out why the back bedroom radiator is working ok, unless
water is reaching it via the ho****er system.
You probably don't have a fully pumped hot water system. The water is
heated by gravity (relying on the fact that cold water is heavier than
hot water, so hot water rises around the circuit. This happens in the
radiator circuit as well - which explains why the upper radiators are
hot while the lower ones aren't.

* How easy / expensive is it likely to be to replace the pump on this
'antique' boiler (getting someone qualified to do it that is)
The pump isn't in the boiler - it's a separate unit something like
this: http://www.screwfix.com/app/sfd/cat/...72726&ts=77549
That's easy to replace. 100 quid max for a plumber to do it.

* If I replace the back boiler, could I use a combi boiler but basically
keep the same hot water/ central heating setup. The back boiler
currenly heats water in a hot water tank in the airing cupboard.

There's no point. You can use a system boiler in place of the back
boiler and still keep the tank but the whole idea of a combi boiler is
that it heats water instantly as you need it. You'll get much better
showers from a combi, but if you choose a "cheap" one you might not
get the flow rate you want when filling up the bath.

* Are there any reasons other than aesthetic why I can't put a combi
boiler on the fire place using the chimney as a flue. i.e need to be
certain height above ground, thereby minimising changes in the plumbing
which is all currently situated there.

The flue needs to go outside - you can't flue into the chimney. Modern
combi boilers are room sealed appliances. They take the fresh air they
need for combustion from the flue.

I think it wouldn't be easy to get the flue all the way up the chimney
and out the top. There are maximum limits on flue lengths anyway
specified in the boiler's installation manual.

* If I went for a condensing boiler, other than finding a way to run off
the condensate, could this be situated on the fire place as above.

Chances are that you will be forced to have a condensing boiler. The
condensate output must fall at around 2 degrees or more to an internal
trap or external drain or soakaway. If you can't get the fall for
whatever reason you'll need a separate condensate pump which collects
condensate in a tiny tank and pumps it out when the tanks is full. A
big boiler might produce 2 litres/hour condensate.

Apart from the condensate I don't think there is any reason why you
shouldn't put the boiler on the fireplace.

Mr F.

In an earlier contribution to this discussion,
angusclaydon wrote:

I currently have a baxi bermuda 551 back boiler central heating / hot
water system. It has a gas fire on the front
which is no longer used.

When I turned on the central heating - it's been off since last
winter - the there was no characteristic gush of water surging round
the
system and the radiators don't work, apart from one in the back
bedroom.

I bled the radiators, checked the valves on the thermostatic radiator
controls weren't stuck, but still no joy.

After looking at the boiler and reading some previous posts, I am
coming round to the idea that the pump is not working. The boiler
still heats water for the hot water system but it isn't coming on and
staying on for any period of time as it usually did when the central
heating was on. I can't quite work out why the back bedroom radiator
is working ok, unless water is reaching it via the ho****er system.

* How easy / expensive is it likely to be to replace the pump on this
'antique' boiler (getting someone qualified to do it that is)

As someone else has said, the pump is a stand-alone unit - not part of the
boiler. If the pump hasn't been used all summer, it may simply have seized
rather than failed completely. If you can find it, unscrew the endcap (very
little water will escape) and try to turn the shaft with a screwdriver. You
may be able to free it. If not, it is not too difficult to replace -
particularly if it has functional isolating valves either side, enabling it
to be removed without having to drain the system.

The pump is probably located fairly near to the boiler - it could even be
inside the chinmey breast, or it could be under the floorboards if you have
a wooden floor downstairs.

If an upstairs radiator gets hot without the pump running, it means either
that the radiator is connected to the gravity hot water rather than heating
circuit, or that there's *some* gravity circulation within the pumped
circuit, as sometimes happens.

If you *do* decide to replace the boiler, you will need a lot of plumbing
and control system changes to bring it up to modern standards - and meet
current building regs - and you need to find a more suitable location for
the replacement boiler.
--
Cheers,
Set Square
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angusclaydon wrote:
I currently have a baxi bermuda 551 back boiler central heating / hot
water system. It has a gas fire on the front
which is no longer used.

When I turned on the central heating - it's been off since last winter
- the there was no characteristic gush of water surging round the
system and the radiators don't work, apart from one in the back bedroom.

I bled the radiators, checked the valves on the thermostatic radiator
controls weren't stuck, but still no joy.

After looking at the boiler and reading some previous posts, I am coming
round to the idea that the pump is not working. The boiler still heats
water for the hot water system but it isn't coming on and staying on for
any period of time as it usually did when the central heating was on. I
can't quite work out why the back bedroom radiator is working ok, unless
water is reaching it via the ho****er system.

* How easy / expensive is it likely to be to replace the pump on this
'antique' boiler (getting someone qualified to do it that is)

* If I replace the back boiler, could I use a combi boiler but basically
keep the same hot water/ central heating setup. The back boiler
currenly heats water in a hot water tank in the airing cupboard.

* Are there any reasons other than aesthetic why I can't put a combi
boiler on the fire place using the chimney as a flue. i.e need to be
certain height above ground, thereby minimising changes in the plumbing
which is all currently situated there.

* If I went for a condensing boiler, other than finding a way to run off
the condensate, could this be situated on the fire place as above.

many thanks
angus

Thanks for your help

In an earlier contribution to this discussion,
angusclaydon wrote:

angusclaydon wrote:
I currently have a baxi bermuda 551 back boiler central heating /
hot water system. It has a gas fire on the front
which is no longer used.

snip

Thanks for your help


Have you fixed it - or decided what to do?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Well, I have found it, and got the end cap, haven't managed to get a
screwdriver in as its awkwardly positioned next to floor joist

Looks like I will be able to get it off as its got taps either side of
it! Also been trying to get my head round the timer wiring as I
replaced that last year too with electronic one, as it doesn't appear to
be independantly fused ...

rgds

Set Square wrote:
In an earlier contribution to this discussion,
angusclaydon wrote:


angusclaydon wrote:

I currently have a baxi bermuda 551 back boiler central heating /
hot water system. It has a gas fire on the front
which is no longer used.


snip

Thanks for your help



Have you fixed it - or decided what to do?

In an earlier contribution to this discussion,
angusclaydon wrote:

Well, I have found it, and got the end cap, haven't managed to get a
screwdriver in as its awkwardly positioned next to floor joist

Looks like I will be able to get it off as its got taps either side of
it! Also been trying to get my head round the timer wiring as I
replaced that last year too with electronic one, as it doesn't appear
to be independantly fused ...

rgds

Sounds like you're making *some* progress. Is it possible that - due to your
wiring changes - the pump isn't being told to run? Can you get at its
connections to make sure that they're live when they should be, or can you
temporarily wire it into a 13A plug to see whether it runs when you *know*
it has power? [Even if you can't get a screwdriver in, you may be able to
get a finger in to check whether the spindle is going round.]
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Set Square wrote:
In an earlier contribution to this discussion,
angusclaydon wrote:


Well, I have found it, and got the end cap, haven't managed to get a
screwdriver in as its awkwardly positioned next to floor joist

Looks like I will be able to get it off as its got taps either side of
it! Also been trying to get my head round the timer wiring as I
replaced that last year too with electronic one, as it doesn't appear
to be independantly fused ...

rgds


Sounds like you're making *some* progress. Is it possible that - due to your
wiring changes - the pump isn't being told to run? Can you get at its
connections to make sure that they're live when they should be, or can you
temporarily wire it into a 13A plug to see whether it runs when you *know*
it has power? [Even if you can't get a screwdriver in, you may be able to
get a finger in to check whether the spindle is going round.]
It doesn't make a sound when wired directly... its a dodo

Just sourced a wylo (£30 something) locally as its cheaper than the
original grundfos (£57 yikes) ...

Do I have to bleed air out once the new one is in? Getting to the back
of the boiler is nearly impossible ? or maybe I can just bleed it out of
the radiators

rgds

In an earlier contribution to this discussion,
angusclaydon wrote:


Just sourced a wylo (£30 something) locally as its cheaper than the
original grundfos (£57 yikes) ...

Do I have to bleed air out once the new one is in? Getting to the back
of the boiler is nearly impossible ? or maybe I can just bleed it out
of the radiators

rgds

If the valves work ok, you'll only introduce a pumpful of air - which isn't
very much. It should bleed itself with the end-cap removed. Any remaining
air should either go up the vent pipe or collect in the radiators. Try to
mount the new pump in a way which enables you to get at the end of the
shaft - or drill a hole through the joist for screwdriver access.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

"angusclaydon" wrote in message
news
I currently have a baxi bermuda 551 back boiler central heating / hot
water system. It has a gas fire on the front
which is no longer used.

snip

You do not have to have a condensing boiler if replacing a back boiler. My
mate has had his 1970's Baxi Bermuda with 70's style gas fire replaced with
a new Baxi back boiler and coal effect gas fire. Fitted by a Corgi installer
who totted up the "points" (major problems, no easy condensate drain and no
space for external flue not near windows or external doors) so a
conventional back boiler was fitted. Also converted to fully pumped in the
process. About £2.5k I seem to remember.