Lost: One Central Heating Pump. Reward offered (in reputation points ;)

I have a wet open-vented central heating system, and I've turned it on after six months to find the radiators aren't getting hot. We suspect the pump is clogged with sediment. The problem is, we can't find the pump. I've had a plumber round and we've searched around, even pulling up some floorboards near the hearth, but we can't find it.

Where should I look? Any tips for locating the pump?

The central heating boiler is upstairs, the control panel is downstairs, there are three radiators downstairs, and four upstairs.

  • I assume you've checked it's not integral to the boiler?
    – ChrisF
    Oct 23, 2010 at 22:31
  • It could be a gravity fed system.
    – ChrisF
    Oct 23, 2010 at 23:23
  • The plumber had the cover off and had a nose inside, so I assume it's not integral, but I will have a check by getting the make and model and checking on the web. Oct 24, 2010 at 13:02

3 Answers 3


There must be a cable going to the pump from the controller, so you may be able to find it using a cable tracer.

  • Starting from the boiler and following the cables led me to the pump. It turned out not too far from the boiler, but under a desk which I suppose I hadn't wanted to move. Lesson learned? Start at the boiler and follow pipes and cables outwards. Dec 7, 2010 at 21:57

Are the pipes getting hot? Are there valves (that have been shut)?

I wonder if the system you have only comes in either gravity fed or pump fed version; the product manual or marketing materials might tell you. Do you have the manual for the system lurking about? If you know the make and model number of the central heading boiler, you might be able to find the docs online by searching for the make and model number using Google/Bing!/Whatever.

  • Hi -- the overflow pipe gets hot, and then shuts off as water fails to flow and it overheats. The plumber was fairly convinced that it was the pump, although I will certainly check the make and model to see if it's gravity fed. Thanks. Oct 24, 2010 at 13:01

It can't possibly be a gravity fed system, with the boiler upstairs. Steam must rise, but more importantly, when the steam condenses, only a pump will make the water return to the boiler. Is there a return line? A picture might help.

Could this be an open loop system? So the hot water is discarded after use? Nah, that would be incredibly wasteful. Scrap it and replace it if it is.

So the pump must be somewhere. I can't believe any sane person would install a system like this without providing access, at least in the form of an access panel. Of course, I could believe that someone might later, unthinkingly, box it in/close it off. What is the vintage of the system?

So if these are old steam radiators, then a pump could be at the bottom of the loop. Look there. If they are baseboard style, modern radiators, then my gut says the pump is near the boiler, and since you can't find it, perhaps built into that unit.

  • I don't think the system is particularly old -- the house itself was built in the '60s, but the boiler was added some time after, we think, and replaced a different system. Hard to tell beyond that. Oct 24, 2010 at 13:05

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