by htg engineer »
Wed Dec 16, 2009 7:47 pm
If it a gravity hot water system, it may just be the age of the system build up of limescale etc etc in boiler/primaries/ heating coil.
If you do not want to change the system I would recommend converting to pump assisted. Put a tee just after the pump, after the tee fit a two port valve, connect the branch of the tee (with 15mmreducer/pipe) to the heating return.
When Hot water only is selected the two port valve will be closed and the water will be pumped from the boiler back down the heating the return and up the primaries to the tank - works well.
htg