I have a baxi bermuda 550 back boiler thats gone a bit tempermental, it seems that it does not work to the timing switch but comes on when it feels like it, any ideas anyone,thank you

Denis, January 2010

motorised valve is what lets you choose between heating and hot water. you may have 1, 2 or none depending on system design. most lokely place to find it is near the pump. usually at the hot water cylinder or in cupboard next to chimney breast, but could be anywhere. it's the motorised valve (if you have one) that sends the power to the boiler to fire it up.

Ian, January 2010

thanks ian, we did change the timer to a digital timer but to no avail, i do feel thats its not too big a problem but its finding which is the fault, what is the motorised valve? thank you

denis, January 2010

probably isn't a fault with the boiler. most likely problem with controls i.e. timer, motorised valve, pump, thermostats

Ian, January 2010