I think that I have an air lock at the bottom of my hot water system?

Diverter valve sounds a good possibility, then again most 3 port valves de-engergise to the HW position so logic would state that the heating would thus be the problem. however there are exceptions to the rule!!! try this..... make sure the rads are cold..... whack the Hot water ONLY on and wait for the system to warm up..... now feel the pipe as far from the diverter valve as possible (about 30cms should do) if its hot then the valve is sending the water down the CH circuit..... another possibility is crap in the coil causing restricted flow and poor hw performance.... start with this test though.... oh, and make sure if its a long run to the cylinder, the pipes are lagged....

dave, BG
February 2009

Hi Darren,

Thanks for the reply.

The central heating works fine. I have a motorised 3 way valve, which is fairly new and is working fine. I can select either hot water or heating, or both together, without any problems. The problem with the hot water pre-dates the new valve.

The hot water side of the system is very hot coming out from the pump, but cools significantly by the time it reaches the cylinder on the next floor.

Any other ideas?

Plumbed out
February 2009

hi

i am assusming that the central heating is working ok

it sounds like you have a system boiler, which uses the heat from the central heating to heat the water, it sounds like you might have a problem with the diverter valve/switch and one way to find out is switch the hot water on and see if it heats up the rads, as could be stuck open, if this works you will need to get a plumber in to repalce the part,

darren
February 2009