Hot water but no heating

Can anybody help me please?

I have a BoilerMate ll fitted and up until yesterday, everything worked fine... Now the hot water is available but the heating isn't.. The boiler downstairs fires up as normal but still there is no heating

Many thanks in advance

Hi Phil,

Time clock failure, room thermostat failure, pump failure, in that order of likelihood!

Cheers Mike

Hi

I have a similar problem. Hot water is working fine but central heating is not.

The clock was replaced two years ago. It is digital and seems to be fine. The PCB is working fine when I remove the test link. The thermostat clicks when I turn it so I assume this is also fine. That leaves the pump. It is a grundfos 15-50x18 selectric. It is not working at all. It's as if it has no power to it. Removal of the cap shows that the spindle rotates freely. Pipe coming in is too hot to touch. Pipe below is touchable. All rads are cold.

Do I need a new pump? If so, how would I drain the boilermate in order to fit it?

Any help would be much appreciated. Thanks

Don't worry - sussed it out. Was the clock after all.

Off to order a new clock.

Thanks anyway.

John - I have *exactly* the same circumstances you describe (hot water, no heating, relatively new digital clock, pumps rotate freely).  

You said "The PCB is working fine when I remove the test link." - can you elaborate?    How can i check the PCBs?

Also, how did you come to the conclusion that the clock was broken?   Anything obvious?

Thanks
ian

Best thing to do is.
If the unit is hot.
Put heating on via time clock on BM II.
Then turn room stat up full if fitted.
Check the pump is working for heating.
If not is it free?
Has it a supply?
No supply then work back.
Has the room stat a supply?
There should be live, neutral & switched live.
If no supply at stat.
Then check the time clock.
Mike

Thanks, Mike...meanwhile, the heatijng has come back on! I need to do some more diagnostics....might be that when i was checking the pumps i loosened something, might be that the system works on timer but noit with manual switching...might be that it was never broken and i was doing something stupid!

Check the pump drive PCB to.
Mike