Hi i have a Potterton Puma 80e combi boiler. With the central heating on the upstairs radiators are getting very warm and downstairs is cold. I have tried to balance the system and this only seems to reduce heat across working radiators. The boiler is upstairs meaning downstairs rads are furthest away. I have check and the pump is running however it is extremely hot ( wondering if it could be running slow ). Have also noticed that the flame light comes on for around 20 secs then switches off again, it seems to do this every 5 mins or so. Any help would be great as at the present time quite confused.

Colin, October 2007

This sounds to me like the diverter valve very common on the puma only difficult thing is the backnut whick is difficult to access and can be extremley tight.

Carl, October 2007

Personally I would replace the pump if its more than 12months old, combi pumps work much harder and for longer time spans than pumps in conventional systems.

Wally ladd

wally ladd, October 2007

sounds like air lock shut the upstairs rads and it should push the heat downstairs.

sonray heating, October 2007