I has the radiators drained to change one of the taps and since then, the Ferroli boiler won,t heat the water unless the heating's on as well. The pressure bar increases when the heating is on, then decreases when I use hot water so averages about 1.5. It's starting to creep up to almost 3 as the hot water doesn't work. All help reatly appreciated.

Sharon Baker, October 2008

The heating is totally separate from the circuit that produces hot water. Ferroli only have the new Optimax range that has a diverter valve, so ignore the previous answer if the boiler is quite old. Depending on the model it does sound like the flow meter at fault on the hot water side. If pressure is fluctuating on the heating side and the pressure gauge is moving up and down it could be a problem with the expansion vessel. Both faults can be fixed by a trained installer relatively cheaply.

John B, October 2008

sounds like the micro switch on your diverter valve when you put your hot water tap on ther should be a clicking noise within 10 to 20 seconds if you do,nt hear this then it is not switching over an more likely to be microswitch or debris on the diaphram

rob gallagher, October 2008