Hi all, have a problem with my heating system not switching off, Trianco oil boiler 20/25, acl lifestyle control center, mid port valve. I have replaced the hot water tank stat, no fix, then replaced the mid port valve, initially all worked fin until this morning when I switched the system off at the mains to clean out the baffles etc. Re assembled, when switched on again the boiler fired up even though it was not programmed to. The system had been off prior to the fix for some 2 months so I had to reprogram. could the problem be the programmer? might interrupting it have upset it in some way?
Boiler not switching off
- Thread starter timbo2
- Start date
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There is a live 240v coming to the boiler to tell it to switch on.
There must be a live coming from the programmer to tell
the boiler to switch on otherwise it wouldn't.
There must be a live coming from the programmer to tell
the boiler to switch on otherwise it wouldn't.
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You need to trace it through to find where the 240v is coming from
using a multimeter.
Yes frost stat is also a possibility if fitted.
using a multimeter.
Yes frost stat is also a possibility if fitted.
Having replaced the mid position valve the operation of the boiler seemed normal, however it seems to be up to its old tricks again, not switching off. If I remove the programmer it stops. Could it be that leaving the programmer without power for a few months reset the problem which now seems to have re emerged? frost stat is at 3c.
If the programmer is supplying 240v when it shouldn't be then this is the fault.
Although the frost stat may be at 3 degrees is it actually on and supplying
240v only way is use a multimeter to see.
Although the frost stat may be at 3 degrees is it actually on and supplying
240v only way is use a multimeter to see.
Hi, well I have just replaced the programmer and thought all was ok until this morning when the boiler came on again when program said off. I have managed to find out that it is the tank stat which is calling for heat, has anybody any ideas as to what the problem might be?
M
mysteryman
Sounds like a wiring issue to me. I had one doing this years ago, and the wiring was an absolute abortion. It had been connected at the boiler following a Y Plan, but at the programmer as a C Plan, as I remember it.
The thing that makes this one stick in my mind was that the boiler fired while I was in the loft with the system drained - but all the controls were 'off'.
The thing that makes this one stick in my mind was that the boiler fired while I was in the loft with the system drained - but all the controls were 'off'.
I bet you were down out of that loft quick smart! Well I have checked the wiring according to the Drayton wiring diagram and all looks ok. Still have the problem of the boiler cycling on during the day when the programmer says off. When its timed to cycle the pump doesn't come on either. Is a faulty programmer a possibility? The brown wire from the programmer is live even though HW is not called for.
Get rid of that Carpy old ACL Programmer and fit a decent Honeywell ST9400C 
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