Oil filled radiators or central heating

RoysGotProblems

My wife and I work from home and are trying to work out how best to heat the house this winter.  My wife is proposing we purchase modern electric radiators and use them to maintain a comfortbale heat in 2 rooms.  On the other hand I think our modern condensing boiler has got to be more efficient even if we heat some rooms unecessarily.  We have a modern insulated 4 bed 90s house.  Does anyone have a feel for which would be more economical?

QrizB

Mains gas? Use the boiler.

RoysGotProblems

Mains gas, yes.

coffeehound

Is your boiler a combi?  If so, turn down the dial behind the flap to number 3, or lower if you can.  That will run the radiators at a lower temperature and means the boiler runs at higher efficiency

MWT

RoysGotProblems said:

My wife is proposing we purchase modern electric radiators....

I always get nervous when people talk about 'modern' electric heaters, there is an unsaid but somehow implicit expectation that a 'modern' electric heater is somehow going to be more effective than an older one and it really isn't true, 1kW of electricity in is still going to deliver 1kW of heat out.

If you are heating some rooms unnecessarily with the central heating then invest a little in thermostatic radiator valves or just turn off the ones you don't need (prefer the first solution as a little heat keeps damp under control).

Gas still scores over electricity on price for this winter, so I wouldn't be spending money just to get electric heaters that will cost more to run than what you have already.

wittynamegoeshere

Some VERY rough figures... Electricity costs 3-4 times the price of gas.  Your modern boiler should be around 90% efficient.

So, if you're currently spending £100 to heat 4 rooms then heating 2 rooms with electricity will cost...

As electricity is 100% efficient: £100 * 90% = £90

As electricity costs 3x more: £90 x 3 = £270

As you're only heating half the space = £270 / 2 = £135

So my very rough maths says you'll spend more for much less comfort.

As already pointed out, anyone marketing "modern" electric heaters is probably telling a load of lies, be extremely wary.

Almost all electric heaters are roughly 100% efficient.  No heater can improve upon the very cheapest one in terms of efficiency.  Anyone claiming otherwise is a liar.  The only form of electric heating that is more efficient is a heat pump, and that is a big installation job.

Just switch some radiators off or turn them to their frost protection setting, usually a * on the scale.

Rivers_mum

We moved from a house with electric heating to this one with a gas combi boiler and simple thermostats on all the radiators. It’s a far bigger house and we’re now retired so home all day, despite that our bills were far far lower and we’re warmer and more comfortable. Stick with your gas radiators and set them on a very low heat where you don’t need to be just to keep it aired and prevent damp. 

Rivers_mum

Don’t forget that your outlay on electric heaters of any kind would pay for quite a lot of gas! 

BUFF

RoysGotProblems said:

 On the other hand I think our modern condensing boiler has got to be more efficient even if we heat some rooms unecessarily. 

TRVs on your rads? Turn them down in unused rooms.
Mains gas is far cheaper than electricity.

Heinzbean

My new octopus electricity is 21.37 per kwh  Gas 4.01 kwh =  Electricity 5.32 X dearer than gas.

my Gas boiler 24 kw  costs £0.96p per hour to heat the whole house.
 £0.96p per hour while the boiler is running.
 
 If you are happy to have a small electric heater that will keep you warm you could try the halogen electric heaters.
 £20-£25 each.
 on  0.4 kw costs 9p  per hour to run.
 on  0.8 kw costs 18p per hour to run.
 on  1.2 kw cost  27p per hour to run.
 So if you are sitting at a desk all day one of these would be efficient.Pointless warming the whole house.
 
 
 As for central heating the whole house gas is cheapest at the moment.

QrizB

Heinzbean said:

My new octopus electricity is 21.37 per kwh  Gas 4.01 kwh =  Electricity 5.32 X dearer than gas.

my Gas boiler 24 kw  costs £0.96p per hour to heat the whole house.
 £0.96p per hour while the boiler is running.

You gas boiler does not normally cost 96p per hour to run. While it might be rated at 24kW, most of the time it will have modulated down to a lower power and might well be turned off entirely. Also, it's unlikely that you have 24kW-worth of radiators.

If you look at your gas bills for last winter, you'll probably find your CH costs less than 15p/hr to run. My gas bill was 7.4p/hr, on average, during January 2021 (the month with the highest gas use).

Edit to add: I had five minutes so I went round and measured my radiators, then looked up the heat output of similar ones at Screwfix. I have an 18kW boiler but the total rated output for my rads is just under 11kW.