Still pumping

[Rusty]

I've got a strange one to go to tomorrow, oil fired Thermecon system boiler, 2x 2 port wet side, circulation pump won't stop, i've turned the programmer off, tried disconnecting the room stat, still keeps running, any idea's what the problem is? Thanks

 

[stevetheplumber]

I've got a strange one to go to tomorrow, oil fired Thermecon system boiler, 2x 2 port wet side, circulation pump won't stop, i've turned the programmer off, tried disconnecting the room stat, still keeps running, any idea's what the problem is? Thanks

you just have to work your way back from the pump with a tester to find where its feeding from

 

[Rusty]

I had a feeling that was going to be the answer

 

[NickH]

I recently had a similar problem and the system was wired incorrectly. It was S plan and a link had been left in place between the switch live feed TO the boiler and the pump overun feed FROM the boiler, so once the boiler was switched on by the programmer you had a "circle" which could only be stopped by switching everything off at the spur. Simple fix once I spotted it.

 

[dontknowitall]

Sounds like the wiring to me too.

The following might help ...

I called electrician to my last problem and although I didn't watch him do the last bit, I over heard him talking to his boss and them talking about wiring the pump to continue for a little while after the boiler had finished calling for heat so that water could be sent around the pipes rather than risking triggering the boiler's high limit stat. Not sure if this is relevant to your problem, but there might be a clue for you.