Hi, I'd appreciate some help in relation to a problem with my Potterton Suprima 60 and the fact that at least twice a day it does not shut-off CH when the timer tells it too.
To be more precise, I have a tempus 7 timer and a Honeywell DT200 room stat and both have been in place for at least 3 years. When the CH comes on as timed it has a habit of remaining on, even after the timer has gone off and the temperature exceeds that called by the room stat. If left this continues until the house becomes a sauna. This doesn’t happen all the time but is becoming more frequent. When it happens the only way to stop the boiler is to turn the control within the boiler itself off, although the flashing green light indicates there is still a call for heat from something. Also, when the HW is on without the CH the radiators still seem heat up which lead me to think there is a problem with the motorised valve.
I have a temporary solution that fixes sorts it which might help indicate the underlying problem:-
After it happens and boiler is switched off at the controls (still a call for heat exists) I turn the timer on for both HW & CH, turn up the room stat to call for heat, switch the boiler back on, which fires up. I then turn off the HW and set the room stat temperature below current and in most cases this removes the call for heat and I then switch off the CH on the timer. After that the boiler stays off until called by the timer and stats as normal. Bizarre!!
I have read a lot of forums on the Suprima range and the PCB problems, however they are predominantly lockouts rather than these symptoms, but who knows.
I have checked the Potterton (unknown model) 2 way motorised valve for the CH and although the light comes on and off when it should I think there may be an issue as when closed (having taken the actuator head off) it seems the spindle is only at around 1 o'clock rather then fully vertical. The valve behind moves freely by hand.
So, is it likely the issue is the actuator? Even when off can it still call for heat without the stat requesting it? If so how do I identify the model that will fit the same backplate to avoid having to replace the whole valve?
Any help would be much appreciated.
Russ...
To be more precise, I have a tempus 7 timer and a Honeywell DT200 room stat and both have been in place for at least 3 years. When the CH comes on as timed it has a habit of remaining on, even after the timer has gone off and the temperature exceeds that called by the room stat. If left this continues until the house becomes a sauna. This doesn’t happen all the time but is becoming more frequent. When it happens the only way to stop the boiler is to turn the control within the boiler itself off, although the flashing green light indicates there is still a call for heat from something. Also, when the HW is on without the CH the radiators still seem heat up which lead me to think there is a problem with the motorised valve.
I have a temporary solution that fixes sorts it which might help indicate the underlying problem:-
After it happens and boiler is switched off at the controls (still a call for heat exists) I turn the timer on for both HW & CH, turn up the room stat to call for heat, switch the boiler back on, which fires up. I then turn off the HW and set the room stat temperature below current and in most cases this removes the call for heat and I then switch off the CH on the timer. After that the boiler stays off until called by the timer and stats as normal. Bizarre!!
I have read a lot of forums on the Suprima range and the PCB problems, however they are predominantly lockouts rather than these symptoms, but who knows.
I have checked the Potterton (unknown model) 2 way motorised valve for the CH and although the light comes on and off when it should I think there may be an issue as when closed (having taken the actuator head off) it seems the spindle is only at around 1 o'clock rather then fully vertical. The valve behind moves freely by hand.
So, is it likely the issue is the actuator? Even when off can it still call for heat without the stat requesting it? If so how do I identify the model that will fit the same backplate to avoid having to replace the whole valve?
Any help would be much appreciated.
Russ...
