Valiant VCW GB221H does not fire on demand?

Just an update for everyone....I found the bleed screw on the line from the heat exchanger, behind the main cover & bled the system completely of any air - there was a lot of trapped air! Also, I removed the big slotted drive screw in the centre of the pump & physically rotated the internals, freeing them up & the pump no longer gets excessively hot -obviously due to no circulation through the pump! Now my system fires up when I put the central heating on, but still not when the hot tap is turned on? As said earlier, I found a broken spindle on the temperature control valve, so I will be replacing that in the very near future. If I want hot water, I just have to activate the relay switch sitting on top of the diverter valve by hand (this is the lever with the big spring on it. If anyone has any other ideas, I would be most welcome to hear them?

Budgie
September 2009