Hi
We have a Worcester Bosch 28cdi boiler and we are having problems with both heating and hot water.when we run water it gets much to hot, and i mean HOT then cuts out, goes cold untill it fires up again. Also if heating is on raditors dont get really warm as boiler cuts out. have changed pump and air vent. Thanks

Trudy, July 2009

sounds like a thermister problem

steve, July 2009

Thanks Ian,
But we have flushed it all through as suggested by someone else and we have a water softener, so dont think it can be scale, any other suggestions welcome.

Trudy, July 2009

The boiler may be scaled / sludged up, not allowing the pump to circulate the heat away from the boiler causing it to overheat and cut out until it has time to cool.

Ian, July 2009