I have a Boilermate II and the heating is permenantly on full regardless of the setting on the mechanical timer (on, off or timed with no settings activated) and the setting on the thermostat. The pump PCB has had the common buzzing noise for the last 6 weeks but the performance of the boiler has not been effected up until now! I have replaced this PCB and it has made no difference other than the buzzing has now stopped. The thermostat does still click when the setting on the mechanical timer is set to timed so I dont think the problem lies with that. The hot water has not been affected at all. Perhaps the mechanical timer has developed a fault but as the replacement parts are costly I dont want to replace them just to try! Any help or suggestions would be great as it is now starting to annoy me some what! Thanks.
Boilermate II Heating problem
- Thread starter DaveG1
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timer pins 3 and 5 should be the live/switched live for the heating.
3 will probably be the permanent live, 5 will be the switched live, theres a diagram of the switch on the back of the timer anyway. if 5 is always 240v no matter what the selector on the front of the timer is at then the timer is faulty. ive had it a few times.
also, one of the pcb's will hold the heating pump on if its faulty iirc.
3 will probably be the permanent live, 5 will be the switched live, theres a diagram of the switch on the back of the timer anyway. if 5 is always 240v no matter what the selector on the front of the timer is at then the timer is faulty. ive had it a few times.
also, one of the pcb's will hold the heating pump on if its faulty iirc.
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Well after replacing both the delay timer PCB and the Grasslin mechanical timer (like for like tactic 111.2) I still have the problem of the heating permanently being on. Please can anyone shed any light on this as it is really annoying me now! Thanks Dave.
Well the PCB had the buzzing so could have done to be replaced and the mechanical timer was the only other thing I thought it could have been. So I am lost other than the pump PCB but I cant keep spending money on it just to try. Please help!
No the only PCB I have replaced is the pump delay timer as this was the one that was buzzing. My only thought now is that it may be the pump drive pcb but like I said I cant afford to throw money at it just to try each time! Thanks Dave.
Obviously I'm not there to test or inspect yours, but from my personal experience of these it is usually the pump drive board that causes the buzzing 95% of the time.
Still if you have cured the buzzing then hopefully that was the one.
From where I am I cannot see any other alternative than to replace the pump drive board, after all these are the only 2 boards controlling anything
Still if you have cured the buzzing then hopefully that was the one.
From where I am I cannot see any other alternative than to replace the pump drive board, after all these are the only 2 boards controlling anything
Hi yes the system was working properly up until a week ago even with the buzzing that was coming from the delay timer pcb. The thermostat is a Drayton RTS1 and the heating is on no matter what setting it is on even in the off position. If the mechanical timer is set to on then you can still hear the click on the thermostat. I guess it may be the thermostat aswell as the pump pcb. Is there any way I can diagnose the cause of the fault to be either of these? Many thanks Dave.
Stop guessing!
Start with the thermostat.
Turn off power to the heating system, remove the 'stat cover and use a multimeter to verify that it behaves like a switch.
The find the 'stat terminals at the BM2 and do the same test, to eliminate the wiring from the list of suspects.
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follow the wiring diagram on the BM, start at the mains wiring and follow the 240v through the unit, its the only way you are going to find the fault properly. as dave said theres not much left in it that you havent changed. as softus said stop changing things without testing them.
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