Electric or oil central heating

matthewcooper98

Hi there,

I have just bought a 3 bed semi-detached Victorian cottage that has never had central heating installed.

It is not possible to get mains gas, so we are trying to decide between:
- Full electric central heating system with electric boiler and unvented cylinder (e.g. EHC Fusion Comet with 180l direct cylinder)
- Standalone electric radiators with a separate water heating system (e.g. Peta electric column radiators)
- Oil central heating system

(I have largely ruled out LPG due to high running and installation costs relative to oil.)

Having had conflicting advice from a number of plumbers and friends (and other threads on MSE), I have a few questions which it would great to get impartial advice on.

Standalone electric radiators
I am tempted by the low installation costs of standalone electric radiators. However, what would the running costs be relative to full electric and oil? Also, will these be adequate to heat the whole house?

Full electric central heating system
I am also tempted by the lower installation and maintenance costs of the full electric system relative to oil. While these costs are of course higher than the standalone electric radiators, it does of course have the benefit of supplying hot water as well.

I have also been told that the running costs would be only marginally more expensive than oil (and likely to become cheaper relative to oil over time). Is this correct?

It is worthwhile adding that others have said that electric would be expensive and not really adequate for heating such an inefficient old property. As such, they have recommended oil. This seems like the ‘safe’ bet.

Many thanks in advance!

matelodave

I assume that you've got an Energy Performance Certificate for your new home. I should be a good starting point to estimate how much energy you'll need to generate heat & hot water.
Try putting that into a comparison site or two just to get a feel for how much your electricity costs would be. It won't be all that accurate but should give you a starting point. You could also use the same energy requirements to work out how much an oil system would cost to run as well. I'd suspect that the place isn't all that energy efficient so insulation should be your first priority to reduce the amount of energy required.

Heating your house using full price electricity is going to be very expensive whether its with electric radiators or an electric wet system.
A system that enables you to maximise the use of E7 might be worth considering which means either storage heaters or a large thermal store - one that can store enough energy on the cheap rate to heat the house & hot water during the time that you require it. Otherwise you'll be topping it up with full price electricity.
As a rough estimate standard rate electricity is about twice the price of oil per kwh. Cheap rate E7 (midnight to 7am) is about the same price as oil per kwh but the higher rate is usually 2-3p more than standard rate.

When you look at the costs you need to take into account how long you intend to stay there, if it's only a short time then a cheap solution might be appropriate (although it might have an adverse effect when you come to sell).
Over a longer period then the cost of the installation will diminish compared to the cost of the fuel you are using. I wouldn't have thought that the cost differential between a wet electric or wet oil system would have been very significant especially if you take running costs into account but you do have to make space for an oil tank.
If you could get the insulation up to a decent level than it might be worth considering a heat-pump.

Robwiz

Insulating and eliminating heat losses should be your first step. A well-insulated home doesn't need emitters in all rooms – heat rising from downstairs plus solar gain will keep bedrooms adequately warm.

If you can avoid installing wet central heating then do so as it's expensive to install and to maintain. People who use oil regularly report having oil stolen from their storage tanks.

Standalone electric radiators can be very pricey for what they are. All resistive heaters are equal, so 2kW fan heaters from Argos at £9.99 are as effective as a £300 2kW radiator. Maybe not as attractive to look at though!

So much depends on your lifestyle and how you use your house. Experiment with electric heaters and timer plugs for bedroom heating – if the background temperature in the house is reasonable then you may only need heat for a short time when getting up in the morning.

The most cost effective form of heating is an air to air heat pump with a high coefficient of performance (COP). Search online for 'mini split heat pump' for more discussion. A unit like the Mitsubishi SRK20ZMX has a COP of 5.56, which means that it puts out 2.5kW of heat for 450W electricity consumption. With no other heating on in my 4 bedroom house, our AAHP kept downstairs at 19º last night and upstairs at 16º – that was with temperatures below zero outside and frost on the car.

A COP of 5 means that each kWh of heat costs 1/5 your electricity tariff rate. Our Ovo Energy electricity costs 10.99p/kWh, so the cost of heat from the heat pump is about 2.2p/kWh – about half the cost of using gas.

NB it makes more sense to install two small heat pumps instead of one larger one because the COP decreases with size.

An unbiased, scientific analysis by David McKay in 'Sustainable Energy - without the hot air'

To top up your heating over and above what a heat pump can deliver, you could either add a second heat pump or install a wood burning stove, although using cheap heaters from Argos is very cost-effective compared to spending £1500 plus on buying and installing a woodburner!

Smiley_Dan

Robwiz, do you have PV? Do you time the ASHP to be on during peak generation hours, or somehow shift demand in some way? I do this with my freezers etc so that they are off 12am-8am currently...

macman

Electric CH is the most expensive option going, since it will run on Standard rate, not E7.
Oil is the cheapest option to run by far per kWh, and the slight maintenance saving on wet electric CH won't eliminate that.
Since the majority of our electricity is still generated from fossil fuels, and will be for years to come, what makes you think that electricity will become cheaper relative to oil?
The only sensible all-electric option is storage heaters and an immersion heater.

captainhindsight_2

Have you thought of a heat pump or a biomass boiler they can be expensive but when the renewable heat incentive come in it should be a pretty quick payback. I have even herd of companies offering to pay for the installation and they own the system for 7 years and they get the rhi payments (similar to the rent a roof scheme for solar pv) it's not ideal but it could be an option if short on cash.