Best way to operate central heating?

[Charnwood]

replaced the thermo valves on the 2 lounge radiators (where the room thermostat is), both set on 3 so slightly above the 18.5° of the room thermostat

The room stat should be in a room where the rad does not have a TRV, generally a hall. Neither TRV nor room stat settings are terribly accurate. The above is not ideal.

 

[Rich114]

replaced the thermo valves on the 2 lounge radiators (where the room thermostat is), both set on 3 so slightly above the 18.5° of the room thermostat

The room stat should be in a room where the rad does not have a TRV. Neither TRV nor room stat settings are terribly accurate. The above is not ideal.

I've since relocated the room stat to the hall (both small radiators in there don't have TRVs), but thanks

 

[UpgradeME]

The first week after this was 65 units, and the second week (last week when temps really went down to sub-zero), 75.

I still think this is very high though, and should be more like half of those figures?

Have a look at question 6 in the FAQ here - If you convert your 65/75 units, what's the kWh usage? Or tell us if you meter is displaying Cubic Feet or Cubic Meters?

I can't imagine the loft insulation halving our gas bills though, so assuming there isn't anything seriously wrong with the boiler etc. (I'll find out in a few days when the plumber comes over), I'm stumped really as to why our usage is so high?

Have you calculated your whole house heat loss (See here) yet??? - Once you do that, you (we) can more easily identify where the heat loss / gas usage is!! - Changing the figures in that calculator will also tell you how much difference loft insulation, cavity wall insulation etc will make!

 

[Rich114]

Sorry, I'll do the heat-loss calc over the weekend and will post my findings!

 

[UpgradeME]

Sorry, I'll do the heat-loss calc over the weekend and will post my findings!

How are you getting on?