by htg engineer »
Sun Sep 30, 2007 8:20 pm
It depends on the type of system you have, if it's a fully pumped system then yes it may be that the pump isn't working.
If it's a gravity hot water system, then it's more than likely to be airlocked or blocked, as the pump doesn't run for heating the water.
Try venting all upstairs radiators, to let any trapped air escape. And try to access the pump to see if it is running.