Electric boiler

KeithElliott

Advice please...

We have a perfectly good grant vortex oil fired boiler, about 7 years old and serviced every year. It runs our central heating and hot water without any issues.

But we don’t like oil, we don’t have mains gas and don’t fancy a Calor tank again (had one before the oil boiler).

We also have an oil AGA.

Annual bills are about £600 for electric and 4000 litres for oil = approx £2k. Total circa £200/ month.

We’re thinking of switching the AGA to electric (£2.5k to change and 270KwH/week running = £2k/yr ish)

...and the heating & hot water to an electric combi boiler to avoid using fossil fuels (we have a fully electric car too)

We are told we need min 20kw (12 rads, but electric showers and no baths) which is best undertaken by two 10kW boilers in series. Up front cost circa £3.5k. Current req circa 80amp.

Local power distributor is prepared and able to upgrade house current limit by either adding a separate line or converting to 3ph. No price yet.

Scary area is electric boiler running cost. At 80amp and 240V that’s about £4 per hour...but unclear how many hours/ day (year) it would be on.

While we can afford an extra £200/ month average it would be grim indeed if the extra monthly cost of an electric boiler was c. £500/month vs oil.

Does anyone have any experience of electric combi boiler real world running costs for central heating and hot water please?

SonOf

But we don’t like oil, we don’t have mains gas and don’t fancy a Calor tank again (had one before the oil boiler).

What don't you like?
As an oil user myself, I find no issue with it.

We’re thinking of switching the AGA to electric (£2.5k to change and 270KwH/week running = £2k/yr ish)

We have an Electric E7 AGA which has now been discontinued. The replacement for that is much more energy-efficient but will be expensive to buy. Although with trade in, you may do well out of it. We turn the AGA off during warmer months.

Scary area is electric boiler running cost. At 80amp and 240V that’s about £4 per hour...but unclear how many hours/ day (year) it would be on.

That is almost certainly going to be more expensive than oil. You would seriously seriously seriously have to dislike oil for this to be worth it.

matelodave

You can do some simple sums - you get around 10.3kwh from a litre of oil, so if you get through 4000litres thats around 40,000kwh, assuming that you still want the same amount of heat then you'll need that out of your electric boilers as well.

If you can get leccy for 12p/kwh it'll cost you around £4800 to get the same amount of heat as your oil gives you, more if your leccy costs you more.

Electric combi boilers can't take full advantage of E7 because you have to run them during peak times to keep the place warm

Cardew

As above, albeit that oil boilers are not 100% efficient.


Oil costs in the region of 5p/kWh, electricity close to three times as much. AND you are contemplating paying £thousands to double your running costs - and it will decrease the value of your property.


Wecome to the forum

G_M

Wow! 4000 litres pa? Big house!



I use half that on a 4 bed,poorly insulated 150-year-old property. I'm at home most days so none of this '2 hours in the morning and then again in the evening' business!


Having said that I don't use it much in the summer (kettle to wash up and immersion when needed).


Ah! The aga? Hate them! Bet that's what's drinking your oil.......

KeithElliott

Thanks for the feedback and advice.

Why don’t we like oil? Because we’d like to migrate away from fossil fuels. The easiest way to minimise fossil fuel use in practice is to go all electric (albeit by no means perfect). Will one (or even one million) house(s) in the UK migrating from fossil fuels make any difference to climate change? Almost certainly not imo. But it’s a life choice.

Current 4 oven oil AGA uses 51 litres per week (2.5k ish per year). We’re retired and just leave it on to do it’s thing all the time. Other 1.5k litres use/year is for heating and hot water.

The 3 oven new R7 AGA is probably less energy intensive than 270KWH for the conversion but is £10k more upfront.

The oil energy equivalent calculation is very useful..thank you. We pay just less than 20p/ KWH and don’t have economy 7.

My maths is weak but I think it works out as 1500 litres of oil (the non AGA bit) being approx 15k kWh which, at 20p/kWh is about £3k/year. Add 270KwH / week for the Aga conversion ... approx 11k KWH gives 26k kWh/year or about £100/week (just over £5k/ year).

I guess folk with AGAs, electric cars and now it seems electric heating don’t make decisions that are primarily economically efficient.

The real concern is that when the UK starts to encounter power brownouts (or worse), quite likely in the next decade imo, then we won’t have heating, hot water or a cooker! But maybe by then power companies will be sophisticated enough to have a super-premium tariff that allows users to be exempt from loss of power (eg double cost tariff)... who knows!

RelievedSheff

Where does your electricity come from?

Unless you are off grid generating your own then it is still being generated for the most part via fossil fuels.

Andy_WSM

RelievedSheff wrote: »

Where does your electricity come from?

Unless you are off grid generating your own then it is still being generated for the most part via fossil fuels.

.

That's simply not true any more. Maybe 5 years ago it was.

3% coal right now and 35% gas. The rest is "green" in one form or another. So "the most part" is not fossil fuels.

A week ago there was an excess of wind and nearly zero fossil fuels on the grid. As time goes on this can only get better. It is also possible of course to pay for a green tariff, which I and many others do.

You can see the current grid generation and consumption data here.

Gerry1

KeithElliott wrote: »

The real concern is that when the UK starts to encounter power brownouts (or worse), quite likely in the next decade imo, then we won’t have heating, hot water or a cooker! But maybe by then power companies will be sophisticated enough to have a super-premium tariff that allows users to be exempt from loss of power (eg double cost tariff)... who knows!

If you have opted for a smart meter (or are forced to have one) you may well end up cold and dark. They all have the ability for Time of Use tariffs (cripplingly expensive at peak times, up to 41.94p/kWh with Bulb), Load Limiting (restricts you to a few kW and everything is disconnected if you don't comply) and Load Shedding (everything is disconnected when there's not enough juice to go round). Block tariffs also mean that the price per kWh becomes crippingly expensive the more kWh you use.

Going all-electric to go green may be a very noble idea, but it also comes with a very high price tag (both literally and in terms of supply security) when compared to staying with oil. And that's before you even consider traditional power failures...

Owain_Moneysaver

Andy_WSM wrote: »

.3% coal right now and 35% gas. The rest is "green" in one form or another. So "the most part" is not fossil fuels.

And 18% nuclear.

The environmental problem is that, due to transmission losses, burning gas in generators and using electric heating is a lot less efficient than burning gas in a domestic central heating boiler with close to 100% efficiency.

And that's reflected in the cost of electricity compared to gas, of course.

Andy_WSM

Owain_Moneysaver wrote: »

And 18% nuclear.

The environmental problem is that, due to transmission losses, burning gas in generators and using electric heating is a lot less efficient than burning gas in a domestic central heating boiler with close to 100% efficiency.

And that's reflected in the cost of electricity compared to gas, of course.

Nuclear is an essential part of the mix as it provides inertia on the grid that is required to keep voltages steady against varying loads - and it's not a fossil fuel, which was the point being replied to.

I don't dispute the inefficiencies of the grid, but again that wasn't the point I was replying to. If cost is no issue then at point of use electricity is cleaner & superior to gas in a number of ways.