CENTRAL HEATING PUMPING OVER

[paulaf]

Ok, my central heating was pumping over in the loft - expansion tank hot and overflowing. Was told i needed powerflush. Powerflush completed and guess what - still hot and pumping over. Had pipes going to loft from pump cut and re worked and its resolved the problem i think.
Expansion tank is lukewarm? is this correct?
Did my system need flushing or did I have a blockage in the pipes which caused the issue?
Powerflush has come at a premium and now I am arguing it wasnt required?

Any professional help is much appreciated.

Cheers
Paula

 

[stem]

Blockages can cause pumping over, so can incorrect piping, so it's impossible to say without seeing the system as it was. If your system contained 'sludge' the powerflush would have been worth doing anyway. If done properly, it will improve the operation of the system and extend component life.

And, yes it is normal for the water in the expansion tank to be lukewarm. As the system heats up and the hot water expands, the additional volume goes back up the pipe and into the expansion tank, there can also be a small amount of heat transfer via conduction & convention.