Why does Ferroli F24 Combi Boiler water go hot and cold?

There are two devices on this boiler that sense domestic hot water flow. One is on the hot water outlet side and is called a thermister. The other is on the cold water inlet side and is called a flow meter. It's possible the fault could relate to one or the other of these. The thermister is the least expensive to replace. Start with that.The manual give a good description of how replace both devices.

Jamie
February 2010