potterton suprima 50 not working

[lelanderson]

Hi can anyone help. My gch/hw is very temperamental. The boiler does not heat up when the temperature control says 'below' - green light on. Also, i have to have it switched on all the time as the timer isnt working to switch on/off as required. When i press the reset button - nothing happens. It seems there are a lot of problems with this. I got a local corgi engineer to look at it and he said £400 to replace the diverter valve. Is this correct - a friend thinks it could be the pcb. Any advice greatly appreciated as im at my wits end!!!

 

[MANDATE]

I think I'd go along with your friend, it could of course be something else but if it's intermittent I'd certainly look at the pcb. As for the diverter valve, well I think that only becomes a problem when it affects the heating while the boiler is functioning OK for hot water.The valve problems are usually a stiff spindle (test by turning), a faulty motor ( replaceable for about £15) or faulty circuit board ( actuator head replaceable for about £40).
With the actuator head off the valve you can observe it moving to the different positions and check the voltages, proving if its faulty or not.

 

[croydoncorgi]

That's a VERY expensive valve!

 

[ChrisR]

If it is the valve and it's the type where you can't change just the head, it means draining down which can make it a v long job if you're unlucky with refilling. Mandates numbers are parts only, no labour.