Setting on Frost stat Honeywell t4360a

[dashforth]

I have a frost stat fitted on the external wall next to my boiler in the loft. I also have a pipe stat on the return set at 10 degrees.

What I am not clear on is the setting on the frost stat. When I take the cover off I can see the 5 degree arrow pointing straight upwards. I understand that I can turn the stat down to 3 degrees by turning the dial clockwise. However the dial appears to be able to turn a little further than where I guess 3 degrees should be. Should I simply turn the dial as far as it can go clockwise safe in the belief that it is now set at 3 degrees? The reason I want to change the setting is the boiler keeps coming on more often than I think it should. Another thermometer indicates the air temperature is around 7 degrees when the boiler comes on. Is the frost stat faulty or is it just that the setting is unclear?

 

[D_Hailsham]

Try setting the frost stat to 5 degrees and the pipe stat to 20 degrees.

 

[dashforth]

Try setting the frost stat to 5 degrees and the pipe stat to 20 degrees.

If I make the changes that you recommend the boiler will come on more often and stay on for longer - or have I completely misunderstood how these devices are supposed to work?

 

[D_Hailsham]

I should have put it as a question: what happens if you set the frost stat to 5C and pipe stat to 20C?

I know that, in theory, the boiler should come on more often and stay on longer, but need to know if it does in practice.