Heating one room vs Central Heating puzzle

i8change

My Worcester Bosch 28iRSF Gas Combi (non-condensing so around 80% efficient) has a Minimum output of 10.5kW for Central Heating.

The Bathroom (with two outside walls) radiator is locked open to prevent the boiler "short cycling" but I can shut all the others off with their Thermostatic Valves.

When I am working at home, alone, in the winter months am I right in thinking that it would be cheaper to heat the one room I am in with a 2kW Electric Convector Heater? Or would it be cheaper to use the Central Heating and heat just the work room radiator plus Bathroom radiator?

I would be using the Central Heating in the evening (for Lounge, Hall & Bathroom, but not bedrooms) so this is for daytime only.


Per Annum we use around 15,000kWh Gas and 3,000kWh Electric.
Currently pay:-
Gas: First 2680kWh @ 6.5p each, then 3.2p each thereafter.
Electric: First 900kWh @ 25p each, then 9.5p each thereafter.

We have good loft insulation and full double glazing but the (1926) wall cavities were not big enough for insulation. Rooms are single brick separated.


Many thanks for any replies.

moonrakerz

If you do a site search this question comes up regularly...........

Cardew

There are too many unknown parameters for anyone to give an answer.

The fact your boiler has a minimum output of 10.5kW is of little relevance as it is not firing all the time.

In most situations gas would be cheaper

i8change

Thanks for the replies, it was the boiler minimum output that got me wondering.

Guess I will have to try both in a settled spell and see what happens, meter wise.