Suprima 50 - New board problems?

[uk1]

If the boiler was staying on longer before then it must have been getting hotter - try turning the boiler stat up!
Sounds like you need a new pump - perhaps it's now so knackered that it's hardly pumping any heat out so the boiler heats up quicker and turns off...

Thanks Chris,

I'm not certain the boiler did stay on longer. I wouldn't know. I'm not sure the pump is the cause because it was the pump that stayed on all day every day before the new board - but if Baxi-Potterton are to be believed, should have stopped/started, and the behaviour only changed on the change of the PCB. The pump may not be as good as it was but it doesn't seem likely logically to be the cause of the change in behaviour.

 

[croydoncorgi]

The pump should NOT stay on 'all day'. It should run all the time there's demand for heat (programmer + room / cylinder thermostats) AND during the pump overrun which is determined by the boiler based on time / internal temperature (can't remember which on the new board).

If the pump startup noise is THAT bad, you might do better to investigate the problem with the pump!

 

[ChrisR]

That's what I meant - the pump shouldn't make any noise like that, so change it.

 

[uk1]

That's what I meant - the pump shouldn't make any noise like that, so change it.

Thanks - appreciate the feedback - as I said earlier in the thread:

>>The sound is like a rattling chain every time it shuts the pump - but not when it restarts. I've listened to the diverter and pump - it doesn't seem to be from here - but I can here the noise through the radiators. Any idea of what this might be would be appreciated. <<

The pump isn't making the noise. The sound emnates from all radiators but not from the pump.

 

[croydoncorgi]

If the noise actually comes from the radiators themselves (especially upstairs) and / or the pipes leading to them, chances are you're listening to air (or another gas, eg. hydrogen) redistributing itself as the pressure from the pump ceases.

Have you actually bled your radiators already?

If not, do it.

You never described your system - I'm assuming there's an F&E tank in the loft. It would also be very worthwhile to check that the system is not 'pumping over' while the pump is running - water running into the F&E tank from the vent pipe. If so, the problem is likely to be a partially blocked cold feed pipe. This needs fixing urgently, to get rid of the noise and to prevent holes in your rads!