my boiler is on hot water only. but it keeps firing up and my radiator is on full, how do i switch it off safely,it is a potterton performer 24 .if i just put it on off at top of dial,is this safe.

evelyn, August 2007

have had the same problem before and it was due to a faulty flow microswitch assmebly basically always calling. The water will pass into the rads as it is acting as a bypass and resting in c/h mode.
As you open the boiler it is the switch assembly that sits at the front of the brass section, the wires connect to the pcb and pump. Cost around £30 to change this and will be cheaper than the pcb and diverter if they get changed for no reason.

hope this helps, let us know how you get on

andy, August 2007

Yes, if you set it to the zero mark that will turn it off. It sounds like you have a fault with the pcb. Just a couple of things to check though. 1, make sure its definately in hot water mode, there are 3 symbols on the left hand dial, the one with the tap symbol is hot water only, tap and radiator symbol is hot water and heating, and zero is off. 2, if the rads are coming on when you run a hot tap then its a problem with the diverter valve, if your not running a tap and they are coming on while the heating is turned off then its probably the pcb. 3, there are 2 versions of the performa 24, theres the 24 and the 24i. The 24i has a hot water pre-heat mode, if the diverter valve is faulty with this model then the rads will come on also. Like i said earlier though, if all the info you gave is correct then the pcb is the most likely cause, this cannot be repaired, it will have to be replaced. Your best bet is to give Baxi-Potterton a call on 08706 096 096. Hope this has helped.

Neil (Baxi engineer), August 2007

Can you not close the radiator valve? Switching the boiler off where you suggest is quite safe.

Syd., August 2007