Potterton Suprima 50 with an overactive pump

[davidwhittle]

I have a potterton Suprima 50 which is 5 years old. In the night, when the boiler should be standing still, suddenly the pump starts. The boiler is not fired up, just the pump running I have tried reset, no good, can't sleep.
At present, the heating is off and the hot water is on timed. When the pump starts, the boiler should be doing nothing.
Can anyone help?

 

[davidwhittle]

The bolier is fitted within the house so it is not in cold conditions.

It says in the instructions that the boiler has a 'Pump Overrun' facility which will turn the pump on for a few minutes every day. I guess that it is this function which is turning it on - but it doesn't turn off.

 

[diybristol]

Check out which board you got in it, there have been countless problems with the Suprima 50...

http://www.cambourne.info/boilerparts.html

I had countless problems with it shutting down, eventually had a whole new board put in it just about under warranty, has been ok since.

If it runs with Microbore it seems to run badly if air in system anywhere (even in pump)

 

[ChrisR]

[code:1]It says in the instructions that the boiler has a 'Pump Overrun' facility which will turn the pump on for a few minutes every day. I guess that it is this function which is turning it on - but it doesn't turn off.[/code:1]

There is pump-overrun, but that is only to extend the pum run at the end of a firing, to get excess heat out of the boiler.

There is also a pump-exercise run which is very short, and ONLY if the pump hasn't been run for a day. As you say the HW is in use, it should be getting daily use anyway.

So neither of these would cause what you're getting.