Its a difficult probelm to explain and makes no difference if the heating is on or not and is much worse on Cold days. When I turn the hot water on the boiler fires up but after 10-30 secs goes of then gos on and off like someone is switching the gas on and off. The higher I try and have the temp of the water the worse it gets. Now cannot even have a shower on a cold day!!

Baby Gear - Combi - Centre DX - Mango