A.Lee wrote:

Lieutenant Scott wrote:

Can someone explain the use of a heater INSIDE a mechanical (bimetal
strip) room thermostat? (It usually just seems to be a resistor placed
near the bi-metallic strip).


It is to make the thermostat/heating more efficient by allowing the stat
to 'predict' a rise/fall in temperature.
If the stat is in good condition, it does work better than a plain
on/off stat, where the temperature can fall/rise a lot more than one
supplied with a neutral.
It wil also save you money by turning off/on the boiler more
efficiently.

Alan.


Or another way to look at it is it narrows the thermostat's hysteresis, ie
makes the off-on temperature closer to the on-off point.



--
Tim Watts