Boiler will not switch off when the timer clicks off

[GCR99]

Hi all
I have a Worcester Danesmooor 15/19 oil boiler and a Drayton LP522 programmer in the airing cupboard. This is all wired in to a junction box and works fine until the timer clicks off and the boiler stays on. The red light on the boiler will not go out and I have to cut the power at the junction box to stop the heating at night, otherwise the pump hums away merrily all night.
There are two mid position valves one of which appears to move OK when the heating is switched on to HW and CH.

I was considering changing the Drayton programmer but will take advice if anyone believes they can help in this issue.

 

[kevplumb]

There are two mid position valves one of which appears to move OK when the heating is switched on to HW and CH.

one of them is stuck or the microswitch inside is

 

[GCR99]

There are two mid position valves one of which appears to move OK when the heating is switched on to HW and CH.

one of them is stuck or the microswitch inside is

Thanks for the prompt reply. I believe they can be opend and oiled with WD40?

 

[kevplumb]

if its a sticky valve yes

you can remove the actuator and try

if a switch it won't do any good

you can replace the switch if you feel competent

 

[GCR99]

if its a sticky valve yes

you can remove the actuator and try

if a switch it won't do any good

you can replace the switch if you feel competent

Hi KevPlumb
thanks for that. When you say Microswitch, you mean there is a small replaceable switch inside the 2 way valve? Forgive my ignorance I am not an engineer.

 

[kevplumb]

yes