Strange plumbing problem - water pump issue

plusman

All of the hot water in the house is supplied via a gas boiler and connected immersion tank. As one bathroom is at the far end of the house, and we wanted to get a good pressure for the shower, we got a pump installed some years ago that pumps both the hot and cold water to that bathroom - so the water to the sink, bath and shower are all pumped. Everything has worked fine until recently when we found we can no longer get any hot water in that bathroom. We have hot water everywhere else in the house, just not at all in that bathroom. It is the only water supply connected via the pump.

The water feeding the bath and shower goes through a thermostatic mixer valve with 3 dials (on/off shower, temperature regulator, on/off bath) and the water feeding the sink is through a separate mixer tap. The pump starts up when any of the taps are turned on and turns off a short while after the water tap is closed.

Irrespective of which tap is used (sink, bath or shower) we get cold water, and this is also irrespective as to which way the sink tap or thermostat (for shower or bath) is turned. If it is turned to the hot only side, we still get cold water and the pump operates.

I would have thought that if there is a problem with the hot water feed (e.g. an airlock) then we would get no water when the tap/thermostat is turned to hot - but we get cold water irrespective as to the temperature setting.

Does anybody have any suggestions as to what could be causing the issue?

Many thanks in advance for any help.

Wookey

If it isn't an airlock at or around the pump then the problem could be that the electrical flow/pressure switch that turns the pump on when asked to by the hot water side is kaput. A spark with a meter and the correct wiring diagram should be able to check it for you.

Ganga

Is it one of those pumps that has a pump fitted to each end of an electric motor? the hot end might have snapped the coupling between the motor and the pump or the pump end might be shot.

plusman

Thanks for the responses. It is a Stuart Turner Monsoon 3.0 bar twin pump, feeding both hot and cold water.

plusman

Thanks for your help and advice.

It turns out that it was an airlock. I had discounted this as I was still getting a good cold water flow on the hot pipes. I contacted the pump manufacturer (Stuart Turner) and they suggested running water with the pump off and then witht he pump on. And it solved the problem.