Recent content by mooky

I'll check it. But from the behaviour described above (pump looks/sounds ok, boiler will happily run for an hour of constant firing without overtemp, radiators nice and hot) you still think its a circulation problem?

Yeah, well aware of the dodgy reputation of the Poterton Suprima boiler PCBs. They tended to exhibit more fatal failures like tripping out for mysterious reasons. Still possible it's that... Nothing to lose by giving them a call...

Righto. My suspicion is not the pump - for reasons mentioned before. But to completely eliminate it as a suspect, it's worthwhile checking it closely. Do you need any sealant to re-assemble? Any gaskets likely to need replacing? It's a grundfos.

When it's not working as expected, the led flashes green slowly after it stops firing. As far as I can gather this means it has reached the designated temp. Since the thermistor was cleared as a suspect, it has to be something wrong with the control circuit. The pot for the temp control looks...

But if I remove the temp sensor in the boiler, it runs for ages before going overtemp (over an hour or more of constant firing). When its running, all the radiators are nice and hot & the house warms up. The hot water is nice and hot... If the pump was not working, I'd have thought that it...

Celebrated too soon.... Replaced thermistor ... still runs for only 30 sec... :| Any further suggestions?

:shock:

Result! Well, partial result... Pulled the boiler's temp sensor (thermistor) from its location and the boiler ran happily for over an hour. Eventually it tripped out on overtemp - but I expected it would eventually. So, I guess it narrows it down to the boiler temp control. Suspect...

Took cap off, just a dribble of water comes out. Seems to be spinning fast/strong. Can't stop it with screwdriver when it's on. Turned pump off. Shaft moves freely, but doesn't continue spinning on its own if given a spin - that's normal? Does it sound like the pump is ok? Cheers

Will have a look and get back to you. Thanks.

How can I check the pump is working/notworking?

Thanks Tony. The things that would lead me to believe the pump is working are: 1. The pipes cool pretty quickly after the boiler turns off. (and the boiler stays off for 4 minutes despite the fact the pipes are luke-warm) 2. The heating works sometimes - and I'd have thought a pump problem...

Ive done a bunch of reading, poking at the heating and scratching my head (not my area of expertise at all - but Ive learned a bit reading here). Fundamentally, the problem is that the heating is only half-working - radiators are only just warm - and the house is cold. However, the twist is...