is unlikely that both valves are faulty.think u need to be a bit more imformative and explain what is happening when and notice what else is happening
if ch and hw switched off does boiler ever fire
does tank stat or room stat fire boiler if raised even when clock switched off
are the valves getting hot indvidualy
if the valves get hot together which is making this happen hot water on or ch ?
if ch and hw switched off does boiler ever fire
does tank stat or room stat fire boiler if raised even when clock switched off
are the valves getting hot indvidualy
if the valves get hot together which is making this happen hot water on or ch ?