Combi boiler lockout on overrun

Joined
10 Dec 2010
Messages
7
Reaction score
0
Location
London
Country
United Kingdom
I've got a Potterton Combi 80 boiler. The central heating works fine. But whenever I run the hot water for an extended period (filling kitchen sink for example) When I have finished, the boiler over heats, makes some horrid gugling noises, steam comes out the top and goes into lockout.

I've ckecked the DHW thermistor and it reads 7.3 kOhms at room temp (which is within spec according to the installation manual)

I'm assuming that the pump is ok, cause if it wasn't, wouldn't the central heating not work?

Any other suggestions?
 
Sponsored Links
Standard fault on this boiler - look at the red light on the PCB. It should go out as soon as the tap water flow stops. Yours doesn't, because the DHW flow switch is sticking on.
 
Many thanks for the quick reply. I've just run the sink, and typically, the problem didn't occur!

Is it possible to clean the switch or is a new one needed?

Any preferences on suppliers of boiler spare parts?
 
Sponsored Links
So I replaced the hot water flow switch, and the problem appears to have been solved. However, when I run the cold tap on full, and then shut it, the red LED on the PCB flashes and I can see a relay firing momentarily. Is this normal? It didn't used to happen before I changed the flow switch.

thanks
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top