The pump on my central heating system has failed - just after the boiler
was serviced the boiler started to make 'cranking' noises as if it was
too hot, so I turned the pump up to top speed (it has been on the middle
setting for over 10 years) but a few days later there was no circulation
(pipes going into and out of the pump were cool, no heat in downstairs
rads) even though I could feel the pump vibrating.

It is an SMC Comet 2-130. I understand SMC don't make pumps anymore. Is
it going to be a problem getting a replacement pump? There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system (it's an ?indirect? system - ie where an air bubble in
the hot water tank divides the central heating water from the hot water
supply)? Any ideas how much I'll have to pay for having the pump
replaced?

Thanks,
John

On Wed, 28 Dec 2005 11:43:07 GMT, John wrote:

The pump on my central heating system has failed - just after the boiler
was serviced the boiler started to make 'cranking' noises as if it was
too hot, so I turned the pump up to top speed (it has been on the middle
setting for over 10 years) but a few days later there was no circulation
(pipes going into and out of the pump were cool, no heat in downstairs
rads) even though I could feel the pump vibrating.

It is an SMC Comet 2-130. I understand SMC don't make pumps anymore. Is
it going to be a problem getting a replacement pump? There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system (it's an ?indirect? system - ie where an air bubble in
the hot water tank divides the central heating water from the hot water
supply)? Any ideas how much I'll have to pay for having the pump
replaced?

I have a spare 2-130 in good condition, which you're welcome to have.
The only problem would be getting it to you, John.

--
Frank Erskine

On Wed, 28 Dec 2005 11:43:07 GMT John wrote :
It is an SMC Comet 2-130. I understand SMC don't make pumps anymore.
Is it going to be a problem getting a replacement pump?

Virtually all pumps are interchangeable. Usual price £30-40, see
http://www.screwfix.com/app/sfd/cat/...72437&id=52890

There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system

Assuming the valve haven't seized, yes.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.12 released 8 Dec 2005]

On Wed, 28 Dec 2005 11:43:07 GMT, John wrote:

The pump on my central heating system has failed - just after the boiler
was serviced the boiler started to make 'cranking' noises as if it was
too hot, so I turned the pump up to top speed (it has been on the middle
setting for over 10 years) but a few days later there was no circulation
(pipes going into and out of the pump were cool, no heat in downstairs
rads) even though I could feel the pump vibrating.

It is an SMC Comet 2-130. I understand SMC don't make pumps anymore. Is
it going to be a problem getting a replacement pump?

It shouldn't be. Most domestic pumps have a standard spacing between
the flanges of 130mm and a standard flange size of 1.5" BSP male.

Other pump sizes are available so it should be easy to find one to
match.

There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system (it's an ?indirect? system - ie where an air bubble in
the hot water tank divides the central heating water from the hot water
supply)? Any ideas how much I'll have to pay for having the pump
replaced?


It should be possible to replace the pump without draining the system
provided that the isolating valves can be turned. It is possible
that they will have seized and will need persuasion with WD40 and
suitable tool. In the worst case, the valves would have to be
replaced.

Replacement pumps come with fibre or similar washers for the valve
unions.

Cheap pumps start at about £25 for the pump. It's worth paying
£40-45 for a good quality one like a Grundfos.

www.bes.ltd.uk and search using "circulator" as a keyword.

You will also find pumps in larger DIY stores and plumbing/heating
merchants.

It's an easy DIY job, but allow time and access to supplies.

Alternatively, heating engineer call out rates seem to start at around
£45-50 including so much time. If there were no snags like having
to drain, then I would have thought it's no more than a 30 minute job.




--

..andy

In article ,
Frank Erskine wrote:

On Wed, 28 Dec 2005 11:43:07 GMT, John wrote:

The pump on my central heating system has failed - just after the boiler
was serviced the boiler started to make 'cranking' noises as if it was
too hot, so I turned the pump up to top speed (it has been on the middle
setting for over 10 years) but a few days later there was no circulation
(pipes going into and out of the pump were cool, no heat in downstairs
rads) even though I could feel the pump vibrating.

It is an SMC Comet 2-130. I understand SMC don't make pumps anymore. Is
it going to be a problem getting a replacement pump? There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system (it's an ?indirect? system - ie where an air bubble in
the hot water tank divides the central heating water from the hot water
supply)? Any ideas how much I'll have to pay for having the pump
replaced?

I have a spare 2-130 in good condition, which you're welcome to have.
The only problem would be getting it to you, John.

Thanks, Frank. I've heard that older pumps are better quality than more
recent ones, so this may be a good idea - I don't suppose you live
anywhere near the Wirral?

John

On Wed, 28 Dec 2005 12:59:11 GMT, John wrote:

In article ,
Frank Erskine wrote:

On Wed, 28 Dec 2005 11:43:07 GMT, John wrote:

The pump on my central heating system has failed - just after the boiler
was serviced the boiler started to make 'cranking' noises as if it was
too hot, so I turned the pump up to top speed (it has been on the middle
setting for over 10 years) but a few days later there was no circulation
(pipes going into and out of the pump were cool, no heat in downstairs
rads) even though I could feel the pump vibrating.

It is an SMC Comet 2-130. I understand SMC don't make pumps anymore. Is
it going to be a problem getting a replacement pump? There seem to be
isolating valves above and below the pump, so presumably no need to
drain the system (it's an ?indirect? system - ie where an air bubble in
the hot water tank divides the central heating water from the hot water
supply)? Any ideas how much I'll have to pay for having the pump
replaced?

I have a spare 2-130 in good condition, which you're welcome to have.
The only problem would be getting it to you, John.

Thanks, Frank. I've heard that older pumps are better quality than more
recent ones, so this may be a good idea - I don't suppose you live
anywhere near the Wirral?

No - I'd have to post it. If you like I'll find what postage would
cost. It weighs about 8 lbs, plus packaging....

email if you are interested.

--
Frank Erskine
Sunderland

On Wed, 28 Dec 2005 12:30:32 +0000, Andy Hall wrote:

It should be possible to replace the pump without draining the
system provided that the isolating valves can be turned.

And actually isolate well enough. If they are the gate type the
chances are that they won't close fully and you'll have leak a nasty
black stainy stuff under 10 to 30' head of pressure.

Even if they do shut and isolate you then have the problem of the
flanges not wanting to part company with the pump.

Changing a CH circulator should be a 30min job tops, it rarely is...

--
Cheers
Dave. pam is missing e-mail

Dave Liquorice wrote:

On Wed, 28 Dec 2005 12:30:32 +0000, Andy Hall wrote:

It should be possible to replace the pump without draining the
system provided that the isolating valves can be turned.

And actually isolate well enough. If they are the gate type the
chances are that they won't close fully and you'll have leak a nasty
black stainy stuff under 10 to 30' head of pressure.

Even if they do shut and isolate you then have the problem of the
flanges not wanting to part company with the pump.

Changing a CH circulator should be a 30min job tops, it rarely is...

I had exactly the same problem about a month ago. I bought a lovely
Grundfos pump, but then discovered that I didn't have big spanners
suitable for undoing the nuts on the flanges.

I contacted a local plumber and assured him that there were isolating
valves, I had the whole job prepared and he only needed to do a bit of
spanner work. He called in on his way home, asked for £25 in cash and
was on his way in well under twenty minutes.

On Wed, 28 Dec 2005 21:56:08 +0000 (GMT), "Dave Liquorice"
wrote:

On Wed, 28 Dec 2005 12:30:32 +0000, Andy Hall wrote:

It should be possible to replace the pump without draining the
system provided that the isolating valves can be turned.

And actually isolate well enough. If they are the gate type the
chances are that they won't close fully and you'll have leak a nasty
black stainy stuff under 10 to 30' head of pressure.

Even if they do shut and isolate you then have the problem of the
flanges not wanting to part company with the pump.

Changing a CH circulator should be a 30min job tops, it rarely is...

Took me about three hours yesterday from coming in to a cold and
electricity-less house to being back up and running. The pump had
failed well enough to trip the RCD.
--
On-line canal route planner: http://www.canalplan.org.uk

(Waterways World site of the month, April 2001)