Honeywell CM927 - suggestions to settings?

[D_Hailsham]

Not quite sure how to measure the surface temp of a radiator.

I use an infra-red thermometer - about £25 from Maplin.

The only thing I find a bit strange is the fact that the flame is on but as the room temp is 21.5C and target temp is 21C no heating is on. I know you gave me the reason from the manual but it just seems odd anyway.

I agree it is confusing. However don't forget that it only displays temperatures to the nearest 0.5C, so 21.5 means somewhere between 21.3 and 21.7. Mine is set to 21C and the actual is fluctuating between 21.5C and 22C, but the flame is showing. If I turn the actual down to 20 the flame goes out and if I turn it up to 22.5C the boiler lights.

What I think the flame means is that there is a possibility that heat may be required. The actual requirement is determined by the PI algorithm. The only time the flame goes out is if the actual temperature is above the PI range, which is 1.5C either side of the set temperature.

It would be interesting to time how long the boiler was on during each cycle and see how this changed.

The main thing is: it works. How is another matter.

 

[jem16]

What I think the flame means is that there is a possibility that heat may be required. The actual requirement is determined by the PI algorithm. The only time the flame goes out is if the actual temperature is above the PI range, which is 1.5C either side of the set temperature.

It should be clever enough to give the consumer what they want - flame on means boiler on, flame on means boiler off.

It would be interesting to time how long the boiler was on during each cycle and see how this changed.

Think I'll pass on sitting out in the garage to time it.

The main thing is: it works. How is another matter.

Too clever for me I'm afraid.