Evening all,

This is probably a very simple question but the theory has got me stumped :D

I've just moved into a new property which has a new gas central heating boiler and a Drayton Digistat 3 thermostat in the living room.

Now I've not used one of these adjustable thermostats before so this is where im confused :)

Reading through the manual for the Digistat it seems very simple, 4 different times of day can be set to different temperatures - so warm for 7am when I wake up, basically off at 8.30 when I leave for work, warm again for about 5pm, and somewhere in the middle after about midnight - simple!

The confusing bit, though, is that the boiler itself has 2 knobs on the front panel - one for central heating temperature it would seem (labelled 1 - 9) and one for hot water temperature (also labelled 1 - 9). Cranking the central heating knob right to the max has predictable results and has everyone sweating in minutes so the question I have, I guess, is what is really controlling the temperature - the thermostat or the manual dial on the boiler? :)

D

Now, I'm no plumber, so I'd check with the likes of Mog, but I'm pretty sure that those boiler knobs dictate the temperature of the water in the actual boiler/system.
All that the roomstat does is control the temperature in the room.

Or to put in another way, the roomstat has NO control over the exact temperature of the water in the heating system. All it does is tell the boiler when to heat the water, and the pump when to pump it around the system.

The boiler actually sets the temperature of the water, but not when it's pumped around the system.

Yep, John is spot on...

The central heating "temperature" control knob on the boiler is just for the temperature of the water inside the radiators. Ideally this does not want to be on maximum (especially if it is a condensing boiler, as it is less likely to condense if someone has not balanced the system right). Number 4 or 5 should be ample.

The drayton room stat you have is a good one (I install them) and it is simply giving demand to the boiler dependant on the time zones/temperature of the room it is in.

Room stats have to be fitted to comply with PART L of the Building Regulations (energy efficiency), yet I still find they cause a lot of confusion because central heating systems are not explained fully by the installer in the first place.

Hope that lot makes sense mate... :thumb: