DIY Doctor UK DIY Forums

Hi,

Hope you can help steer me in the right direction for this fault.

So I have a gravity fed heating system, with a Potterton Profile boiler, Drayton Lifestyle L711 Programmer and Drayton Combi-stat.
(Also Honeywell 3 port valve).

This has all been working well, however have had it switched off over the summer and when I've switched it back on the following happens:

Press Heating on button alone (on Drayton Programmer) = boiler does not fire up
Press Hot water on button alone = boiler does not fire up
Press both on together = boiler does not fire up
Switch either of them off (when set to on but boiler not firing) = boiler instantly fires up (every time)
Then I am able to switch the other one on and both heating and hot water work perfectly until they are turned off.

Just trying to diagnose if this fault lies with the programmer or boiler?

Hope someone may have seen this fault before and be able to advise?

Many thanks

Awkward one, Its either the 3 port valve or the programer. But without being there to test either one of these its not easy to say. Its a shame you cant get hold of a programer as most programer have a standard wall plate that the wire's fit to & you can just clip a new one on.

Thanks for this - we know someone with the same programmer so going to borrow that on Weds to try first and order a new one if that works, before we think about the 3 port valve. We have noticed a bit of a clunk noise from it when it switches from hw to ch so possibly could be that - and know they can be temperamental- it is only a couple of years old though.

Thanks for your advice

The programmer worked - so now bought a new one.

Thanks very much!