Electric Boiler instead of Air Source Heat Pump?

skidnote

I live in an insulated barn conversion in an area which has no gas supply, which we moved into last year after having lived in a house with a condensing gas boiler.  It is heated by a 32kW oil fired boiler (probably a bit on the powerful side for our property - I'm sure 25kW would have worked too).  Inside there is a conventional unvented hot water and central heating system.  This boiler works a treat and heats up the house very quickly.  However, this past winter it has literally been drinking the oil.  At one point last winter, by having the interior thermostat set to around 21 - 22 centigrade, it used 500 litres of oil in around 2 weeks.  This is in the South East of England.  This is clearly unsustainable so we swiftly turned the thermostat down during the day and started wearing many more layers!

I am desperate to get off oil heating before next winter.  The established thinking is that the 'only' alternative is an air source heat pump.  This would probably be feasible in our property, as long as we replaced most of our radiators for larger ones.  I have been quoted around £20,000 for a suitable heat pump (plus extra radiators), which is 18kW (a large one for a domestic property).  Given that one of these will probably cost over £2000 a year to run at current prices, the payback is still many years, even with the £5000 grant - which is not guaranteed.

So my question is, would it be worth considering an electric boiler instead of an ASHP?  I realise that this would be a stupid question if I had gas as an alternative, but I don't.  I realise they are around 100% efficient as opposed to 300% (max) for an ASHP, but they are vastly cheaper to install and would probably, I suspect, not cost that much more to run.  In any case, if something more efficient/green comes along in a few years' time it may still be more economical to replace it then.

Ebe_Scrooge

If gas is not an option, and the upfront costs for an ASHP are prohibitive, then sticking with oil will - by quite some margin - be a heck of a lot cheaper than installing an electric boiler.  Yes, oil prices have shot up recently, but oil is still the best off-grid option in the vast majority of cases.

Gerry1

If you can't afford oil, an electric boiler will bankrupt you.

It's the most expensive form of heating you can have.

Don't even think about it !

molerat

A barn conversion is never going to be economical to heat.  Doing so with an electric wet boiler, probably the most expensive form of heating out there,  will likely bankrupt you.  Get the oil boiler serviced and turn the stat down / only heat what is necessary.

Ectophile

According to https://nottenergy.com/resources/energy-cost-comparison/ based on prices in May,

• Kerosene is about 11.39p/kWh, assuming your boiler is 90% efficient
• Gas Oil is a bit more expensive at 13.62p/kWh, again assuming you get to use 90% of the heat
• Electricity is 33.65p/kWh for a 100% efficient boiler.

If you can't afford the oil, then you certainly can't afford an electric boiler.  At least a heat pump is around 300% efficient, which means it's about the same cost as oil.

lohr500

We live in a converted 5 bedroom farm house in Yorkshire that is not the best insulated. Our boiler is running at 30kW.
In the coldest period this winter (October through to end of February.) we got through an average 13 litres of oil per day for heating and hot water.

That works out at 182 litres for two weeks compared to your 500 litres. Your consumption sounds very high.

In March/April our consumption dropped to an average of 8 litres per day.

How old is your oil boiler? We replaced a theoretical 68% efficient antique boiler last year with a newer 94% efficient condensing version and it has made a massive difference in efficiency.

The last thing you want to move to is an electric boiler. As others have said, it will bankrupt you.
ASHP do have their place, but when I looked at one for our property, it didn't make financial sense. And that was when the grant would have been close to £12 or £13k.

Sticking with oil is most likely going to be your lowest cost option as you can't get mains gas.  

• If you have an old, non condensing oil boiler, consider replacing it with a more efficient one.
• If it is a condensing boiler, make sure the return water temperature to the boiler is less than 54 deg. Above this and it won't be condensing.
• Reduce the room thermostat form 21-22 to 17-18. It makes a big difference.
• If you don't have a smart programmable thermostat/control system (Like Hive or Nest) then get one. It will allow you to programme multiple timings for the heating/hot water and avoid running the system when you don't need it.

matelodave

As everyone has said, leccy is a ridiculous price at the moment at near enough 30p/kw and is likely to be around 40-45p come October. 

Based on a cost of 40/p kwh for leccy then oil would have to be around £4 a litre to match costs (you get roughly 10kwh.litre) for the same amount of heat.

 If you assume that you really did use 500litres then that's around 2500-5000kwh depending on your boiler efficiency. Dunno how much that oil cost you but the equivalent leccy cost would be £1000 for 2500kwh and £2000 for 5000kwh. A heat pump with a COP of 3 would cost between £350-and £650

You really need to put some effort into sorting out the boiler that you've got. Get it serviced, make sure that your controls are doing what they should and improving them if they aren't. Unless its on its last legs or really inefficient then do the sums to see how long it will take to get your money back before replacing it.

Personally I dont advocate stuff like Hive unless you really want to faff around with the heating whilst you are on the bus or in the pub, however a decent programmable thermostat or two controlling the temperatures at times when you are in out, active or sedentary could make a big difference.

Try turning the boiler temp down a bit (or even a lot) so it's not flogging its heart out and cycling a lot. Likewise reduce your hot water temperature to around 55-60 and dont waste it.

QrizB

Everyone else has told you an electric boiler will be very expensive. Let me give you some numbers.

martastik said:

At one point last winter, by having the interior thermostat set to around 21 - 22 centigrade, it used 500 litres of oil in around 2 weeks.  This is in the South East of England.

500 litres of oil contains, in round numbers, 5000kWh. If your boiler is 80% efficient (typical of one in good working order but 20-30 years old) it will have delivered 4000kWh to your heating system.

• Recent prices of oil are around £1 a litre so 500 litres of oil cost around £500, so 12.5p/kWh.
• Electric boilers are 100% efficient so to obtain 4000kWh of heating from one will take 4000kWh of electricity. Electricity currently costs around 28p/kWh, so 4000kWh will cost £1120.
• Heat pumps are potentially 300% efficient, but let's say 250% since there's a fairly wide spread of efficiencies in real-world installations. To obtain 4000kWh of heating from one will take 1600kWh of electricity. 1600kWh of electricity will cost £448. (If you achieve 300% efficiency the numbers are 1333kWh and £373 respectively.)
  

An electric boiler will be more than twice the cost to run than your current oil one. A heat pump might cost slightly less to run than your oil boiler but you're looking at £20k in installation costs.

Ebe_Scrooge

lohr500 said:

• If you don't have a smart programmable thermostat/control system (Like Hive or Nest) then get one. It will allow you to programme multiple timings for the heating/hot water and avoid running the system when you don't need it.
  

Slightly off-topic, I know.  But I've never seen the point of these "smart" things.  In our house (reasonably modern, granted, 18 or so years old), we've got a heating programmer.  You can set the heating to go on and off, three times a day, with different programmes for Weekday and Weekends if you want it.  Likewise for the hot water (which can be completely different to the settings for the heating).  That's way more flexibility than we need, but surely that gives you the option to to set the heating and/or hot water to suit whatever domestic circumstances happen to fit you?  Or maybe I'm just an old dinosaur LOL!

FreeBear

Ebe_Scrooge said:

lohr500 said:

• If you don't have a smart programmable thermostat/control system (Like Hive or Nest) then get one. It will allow you to programme multiple timings for the heating/hot water and avoid running the system when you don't need it.
  

Slightly off-topic, I know.  But I've never seen the point of these "smart" things.

A "smart" Hive/Nest thermostat is supposed to learn what times & temperatures you want. My issue with these things is that they (generally) require a permanent connection to a remote server, and there is often an annual fee to pay. You can get programmable thermostats that will allow you to set a number of different temperatures throughout the day & week - Not quite as "smart" but just as capable. Shop around, and you could probably find one for £30 or less.

I have a programmable system, and it certainly saves me quite a bit of gas (probably 20-25%) compared to the original timer & dumb thermostat in the hallway.

BUFF

Ebe_Scrooge said:

lohr500 said:

• If you don't have a smart programmable thermostat/control system (Like Hive or Nest) then get one. It will allow you to programme multiple timings for the heating/hot water and avoid running the system when you don't need it.
  

Slightly off-topic, I know.  But I've never seen the point of these "smart" things.  In our house (reasonably modern, granted, 18 or so years old), we've got a heating programmer.  You can set the heating to go on and off, three times a day, with different programmes for Weekday and Weekends if you want it.  Likewise for the hot water (which can be completely different to the settings for the heating).  That's way more flexibility than we need, but surely that gives you the option to to set the heating and/or hot water to suit whatever domestic circumstances happen to fit you?  Or maybe I'm just an old dinosaur LOL!

Thing is that people use the term "smart" in different ways.
Some people use it for being able to adjust/start/stop etc. via a mobile phone/tablet/computer.
& then you have "smart" in terms of being more advanced e.g. load/weather compensation/optimal start etc.
& of course, the 2 are not mutually exclusive - you can get a more advanced control that is also able to be controlled from a mobile/tablet/computer.