Could anyone offer any advice on the following problem.
I have a glow worm ultimate boiler with a landys & gyr timing control unit for both CH and HW (options for on, off, once, twice). Recently the central heating and HW stopped working. The boiler fires up fine, the flame is visible and everything sounds the same however neither the radiators or the HW are heating up. The thermostat seems to work fine as it fires the boiler up when CH is on and the temp is above about 15C.
A corgi registered engineer came round and couldn't figure out what was wrong, he eventually suggested the 3-way actuator valve may be faulty. I replaced the Landis & Gyr actuator valve with a Siemens CMV322 22mm
3-Port valve that was advertised as an equivalent part however the problem is still there. I have tried running the CH and HW individually without any success.Would appreciate any help on this
Regards Amar