pump overrun

[tht37]

My first post.
I have an acl lifestile mid position valve 679H340 3060. This hot weather the CH is off. The HW only is set for twice a day, The pump switches off after the morning session but stays on after the PM session. This means the pump is working all night. I think the valve may be faulty. Is there a cure?
Thank you for any info.

 

[honda]

Is your programmer set correctly to switch off the pump in the Pm session?

 

[kbdiy]

I had a similar problem on my Potterton Suprima 70 boiler which turned out to be the PCB, so it may not be related to the zone valve at all (which like you I thought was probably the culprit but not as it turned out)

 

[45yearsagasman]

The valve head may well be at fault, but what boiler do you have?

 

[tht37]

Thanks for your input. The boiler is a Baxi Solo 2 PF. Yes the programmer is set to switch off in the afternoon. The boiler switches off in the afternoon.

 

[45yearsagasman]

Pump should be wired from the PCB on the boiler and it is the PCB that controls the pump over run. If its only the pump that is running (the burner stays off) then it requires testing at the boiler connections. In an OFF period and after the pump has stopped there should only be power on the permanent live connection.

 

[tht37]

Thanks again.
The Boiler (burner) definitely works on the two sessions. The water heats up. If the pcb controls the pump overrun then it seems to be the problem. Why would the valve misbehave every afternoon and behave perfectly every morning?