GG asked ... Fix food processor motor?    |    T asked ... How do I turn the delay off on Electrolux DX302 dishwasher?    |    Helen asked ... How can I mend my Kenwood Gourmet FP505?    |    Roy Turner asked ... Kohlangaz Gosford HE fire?    |    Peter asked ... How can I mend a Powerwasher PRO PRO1800PWE?    |    Click here to ask your question

Radiators suddenly gone cold?

This is my second question about this, sorry. I have 8 radiators in my house, two of which are open. Very recently one of the open rads and one of the trv rads suddenly stopped heating. I have tried bleeding them, tried turning off the working rads to allow the heat to push through, and have just drained and re-filled the system but my troublesome rads are still not heating. The inlet pipes are roasting hot, but there's no heat coming from the radiators themselves. Can anyone please offer me some advice? PS should also mention that the whole system has had inhibitor in it for the past year, and also that it's heatrae sadia electric boilers with grundfos 15/50 pump.
Pamela, January 2007
Make sure the valves at both ends of the rad you will be trying to clear are wide open, it might also be worth seeing if there is a flow control on the pump which you can turn up to a higher speed, most pumps have this feature.
If you still have no joy.... leave 1 valve closed and draw a couple of pints of water through the air vent on the rad, then close that valve, open the other and draw another couple of pints... you will hear air bubbles in the rad if it is indeed an airlock.

Pete, January 2007
Try closing valves on all rads except 1 of the 2 thats not working. If that rad then gets hot open valve to other one thats not working ( I suspect an airlock somewhere).
Hope this helps you.

Pete, January 2007
link Click here to see other fixes for Grundfos.