potterton 10-16 Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[BRYANB]

I have a potterton betaheat 10-16, and the heating will not go off unless I
turn the boiler off-the timer works and is set correctly but the heating will stay on all day can anyone tell me if the boiler stat can overide the external contoller

[plumbbob]

No, but a frost stat can.

[BRYANB]

hI
Thanks for reply but as far as i can see there is no frost stat fitted- but still boiler comes on subject to boiler stat position, I am assuming that the boiler programmer is not registering the external timer settings and cutting c/h in and out at times set would this be possible

[BRYANB]

Hi
Thanks for reply, no frost-stat fitted(I assume it would be visible somewhere)I am thinking boiler control is not recieving and obeying the settings from the external timer because c/h stays on subject to boiler stat settings??but by turning down boiler stat it means rads are cooler than normal but when i turn up boiler it appears to overide external timer and room-stat ??

Thanks

[plumbbob]

There are several models of Netaheat 10-16 and the schematics are different for each. It seems on some models they have a pump overrun controlled by an over heat stat that in certain circumstances, forces the pump to run even if the timer and room stats are off.

Of course it depends on how your system is designed whether this feature is in use. If you have a standard "Y" plan, the pump is controlled by the three port valve and not a timer room or tank stat.

If the boiler is in an unheated space, a frost stat cannot be discounted as easily because they can be incorporated as an integral part of the boiler circuitry.

You need to consult the boiler installation manual as well as grasp exactly how the system is designed.

To answer your question, the boiler water temperature stat cannot cause the boiler to fire overriding the programmer.