On hold

Subsidised gas boiler replacement with an electric?

  • 11 September 2020
  • 14 replies
  • 191 views

Userlevel 1

Would anyone else sign up to a gas-to-elec boiler replacement scheme?

 

Offsetting gas is great, but we are still burning a fossil fuel. I’d rather be a no-gas home.

 

Any plumbers out there? What would that job cost roughly?

If it was £1,000 would anyone go 50/50 with the government / PP?

 

Would value a discussion here if anyone thinks the idea holds water! :)

 

 


14 replies

Userlevel 7
Badge +11

Yes if I win the lottery.

The electric kWh prices for heating (or for anything) are approx. 5 x the kWh prices for gas, and that doesn’t take pipe losses into account, so for the same level of insulation and comfort (and all other things being equal, you can expect at least a five fold increase in heating costs.

On the other hand with a huge investment in a ground source heat pump and solar it is feasible (or it will be for future occupants as payback time is about 20 years)

Also what’s the point of having an electric boiler that pumps water round, (other than the water infrastructure is existing but if you were starting from scratch you wouldn’t do that) you may as well just put electric radiators in and lose the water, I’d rather have a leak in a piece of wire than an unnecessary pipe. Cynical - sorry….

Userlevel 7
Badge +9

I once swapped a clunky 20 year old oil boiler for a 9kw electric flow boiler. In terms of running cost the electric one is way more efficient as its instant heat so used less time than the oil boiler. 

If swapping out a gas boiler it would be more expensive to run unless it was a really old and i mean very old boiler. Modern condensing ones are way more efficient. 

As for install it will vary wildly. I had a hot water tank so didnt need an expansion tank but you also need an individual 30amp fuse and as i had no spare space i had to put in a new consumer unit. Overall it cost £1500 or so. But budget for 800 upto 2000 depending on what setup you have now . 

Remember also that new types of boilers are on the horizon the Government having decreed that new houses cannot have gas boilers. Worcester Bosch and I think Viessman in Germany are developing boilers that start off using natural gas but easily convert to hydrogen in the future. The existing infrastructure for natural gas can take hydrogen.

But, as already said, if you really want an expensive electric boiler to heat your house then you must be better off in the long run stripping out the water based system and installing electric radiators, there now being some very efficient ones. A chap I know replaced his gas boiler with an electric one. His electricity bills are awful.

In the late 1970s early 1980s I had my 1935 house heated by electric panel radiators. It was that or oil, no gas in the area, and oil was expensive. We had had the oil crisis and three day weeks. The running cost then was less than using oil or bottled gas. The radiators were extremely efficient. Sadly, when we came to extend the house and fit additional radiators the panel radiators, or their equivalent, had become prohibitively expensive due to manufacturing standards and designs being changed, such that we had to turn to oil.

However, allowing for inflation, the cost of electricity then was a lot more than we pay today!

I did read a couple of years back that a University in the South West has designed and built a new house that was 100% energy efficient (using insulation, heat pumps and a complete solar roof) and the extra cost to do it was about £1500 more than the normal average build cost. So it can be done.

Having said all this I am shortly to go electric to heat my conservatory for the existing radiator is inadequate, sort of at the end of the line. I believe nowadays Building Regulations say you cannot put a radiator connected to one’s central heating system in a conservatory. Nothing to do with safety but the odd belief that you might leave it on and the heat is wasted! Electric is the most efficient but not for one’s bank account.

Userlevel 1

Good chat guys thanks for the info. Lots of details I didn’t know. Woz I hope your finances improve :)

Cheers

It’s a really nice idea @Edmund81 

Who knows, perhaps we (PP) could partner with an organisation which does this.

Userlevel 1

Thanks Marc 

I should have mentioned in my first post, my idea came from :

We moved from a flat where our monthly bills were Gas 60, elec 40 so £100pm.

We moved to a similar flat in a similar age building with just elec and it cost around £100 pm - the same! 

VERY rough comparison I know but those are the facts as it hit my wallet.

So if I can get 100% true green elec I'd happily give up gas and I'm not a wealthy fellow.

Nice to join the community 😉

Thanks again for posting this idea @Edmund81 

We’ve putting in ‘on hold’ for the time being,

It’s a lovely suggestion but we’re looking at options and it looks like heat pump systems are more efficient.

And in terms of partnering with a heat pump supplier, that’s one for the future, we think, as we’ve got a lot of other work to deliver this year.

Thanks again though :raised_hands:

I have spent many hours considering a dry system to replace my old boiler. I would not consider an electric boiler. That is expensive, if not a retrograde step. The best solution I ended up with are ceramic radiators. They are very efficient, easy to operate and have twice the life of a boiler.

My analysis reveals the capital cost of replacing with such is more than twice the cost of putting in a new gas boiler and replacing all my radiators. OK, to be fair, over the years I would save on maintenance costs and also would not have to replace the boiler again in about 10 years time or just after the warranty expired. From a capital cost aspect I would just about break even in 10 to 12 years.

However, if I fitted them myself the capital cost is only marginally above replacing the boiler and radiators. Above because I would need somebody to remove my existing system. I therefore decided if I went/go that route I would fit them. It is very easy. You hang them on the wall and plug them in to a socket! 

The main issue is running cost. Here a bit of snake oil issues from the suppliers. You are told they are economic, even that they  save you money. I think they do in some cases but only where old night store heaters are being replaced. I was told the formula is for each room is to take the kW output of the radiator, multiply that by your KWh rate, multiply that by 6 and then take 34% of the result. The multiple of 6 is the number of hours the heating is on as an average. The 34% is because these radiators are not on a full hour but on average only need to be on 34% of the time because of their efficiency. I believe this calculation assumes a temperature of 21c but I have no idea how they get that from the formula.

The problem with the calculation is the 6 hours. I only have one room where it is on for more than that and others are around 4 hours, one virtually zero. I spent a long time with a spreadsheet working out the sizes of the radiators for each room, when they would be on and allowing for the fact that for 25% of the year they never would be. I ended up with a running cost of about £200 or so per annum more than my gas cost. The latter in the 12 months to 30/09/20 was about £460. I live in a 4 bedroom detached house in the NE. For the efficiency, and future proofing an electric system would give me I could live with that.

But then I took the total kWhs used by gas for that year and If I assumed the same for electric then my bill would be 5 times more than the cost of gas - over £2k per annum. Of course I need to reduce that by the 34% efficiency but even then the cost is nearly 3 times more. I needed more information.

Now the snake oil bit! Suppliers of these systems always talk of efficiency and they will save you money. They produce on their web sites many letters of appreciation from satisfied customers, but nothing is said about actual running  costs in the real world. Thus I contacted several of such people who had given me quotes asking what their customers’ real experience had been. After all the time in business, remarks that their systems had been checked by universities etc. they must have data and reports on running costs. Those with university connections have surely got the university to calculate averages etc. in given locations? The result? Silence. Absolute silence. With one I asked for the data by email as they must have it, I received a response it would be easier if I rung, so I did. When the chap I spoke to realised I was ringing with respect to my email he said he would ring me back as he was busy. Two weeks have gone by. No phone call.

I think the electric system is very good and much more preferable than a water based system but until someone can give me examples of actual running costs experienced I am hesitant to commit. Having said  all this if your property is smaller, an apartment etc. then doing away with a boiler and installing an electric system would make sense but carefully check what the running costs may be.

Userlevel 7
Badge +8

@G4RHL 

One of the other things to consider if going down the electric system route is the provision of hot water.

My system is a combi boiler, which is now over 20 years old, no hot water tank, no expansion tank, just hot water on demand. If I were to replace it with a dry electric system, I would have the extra expense and effort of having to fit and pipe in a hot water storage tank plus the method of heating it. Although not insurmountable it all adds up to extra expense, which would take a long time if ever to recoup the cost

 

Agreed. If I go electric I would install a tank, probably a system tank or even a thermal store and these would have to be powered by an immersion. The advantage of these is that if ever you are able to install an alternative power source such as solar electric panel, or solar thermal panels or even a ground pump, they can be connected to the tank. 
 

Depending  on where you live thermal panels could be better. As for heat pumps, yes if you are building a house from scratch but otherwise very expensive to install under ground. Above ground they are just like big air conditioning  units generating noise on your outside wall and not wonderfully efficient. A lot more research and engineering needs to be done to make heat pumps viable but I am sure it will happen.

We need cheaper batteries to store “natural” power. They are some distance off. 

My current system is the old fashioned route of 23 years ago, a basic boiler with hot water tank and feeder tanks in the loft. Two for cold water and a third which is the expansion tank for the heating. Our hot water is only heated twice a day and on each occasion for 30 minutes.

An alternative is an instant hot water “boiler” but that does not sound practical or cheap to run.

If I don’t go electric, and it seems likely I won’t, then a combi of 35kws would work. Nothing less. That may not be feasible as it needs a 22mm gas feed and I have no idea where in the house the existing feed is reduced down from 22mm to 15mm. It is not at the existing boiler but under a floor somewhere. If that prevents the combi route then it would be a system boiler of no more than 24kw, 10kw  is probably more than adequate to heat a house, plus a system tank either where the existing one is or in the loft. With an unvented system tank I don’t need any tanks in the loft unless I put the system tank there, and I would get mains pressure hot water. There are some vented tanks that can have a tiny feeder tank just above them and they work on mains pressure as well.

As you are finding there is much to consider! Of course then there is the radiators. My calculations show in three rooms my radiators are too small. Plus I should replace them all anyway. 

My preference is still electric as it practical and so easy to install and control but as said in my earlier post it may not be practical for my bank account. 

Saw this @G4RHL and thought of you 

 

@Marc Nice one! My era as well! I remember the fashion of the lady people depicted!

Userlevel 7
Badge +11

I have spent many hours considering a dry system to replace my old boiler. I would not consider an electric boiler. That is expensive, if not a retrograde step. The best solution I ended up with are ceramic radiators. They are very efficient, easy to operate and have twice the life of a boiler.

My analysis reveals the capital cost of replacing with such is more than twice the cost of putting in a new gas boiler and replacing all my radiators. OK, to be fair, over the years I would save on maintenance costs and also would not have to replace the boiler again in about 10 years time or just after the warranty expired. From a capital cost aspect I would just about break even in 10 to 12 years.

However, if I fitted them myself the capital cost is only marginally above replacing the boiler and radiators. Above because I would need somebody to remove my existing system. I therefore decided if I went/go that route I would fit them. It is very easy. You hang them on the wall and plug them in to a socket! 

The main issue is running cost. Here a bit of snake oil issues from the suppliers. You are told they are economic, even that they  save you money. I think they do in some cases but only where old night store heaters are being replaced. I was told the formula is for each room is to take the kW output of the radiator, multiply that by your KWh rate, multiply that by 6 and then take 34% of the result. The multiple of 6 is the number of hours the heating is on as an average. The 34% is because these radiators are not on a full hour but on average only need to be on 34% of the time because of their efficiency. I believe this calculation assumes a temperature of 21c but I have no idea how they get that from the formula.

The problem with the calculation is the 6 hours. I only have one room where it is on for more than that and others are around 4 hours, one virtually zero. I spent a long time with a spreadsheet working out the sizes of the radiators for each room, when they would be on and allowing for the fact that for 25% of the year they never would be. I ended up with a running cost of about £200 or so per annum more than my gas cost. The latter in the 12 months to 30/09/20 was about £460. I live in a 4 bedroom detached house in the NE. For the efficiency, and future proofing an electric system would give me I could live with that.

But then I took the total kWhs used by gas for that year and If I assumed the same for electric then my bill would be 5 times more than the cost of gas - over £2k per annum. Of course I need to reduce that by the 34% efficiency but even then the cost is nearly 3 times more. I needed more information.

Now the snake oil bit! Suppliers of these systems always talk of efficiency and they will save you money. They produce on their web sites many letters of appreciation from satisfied customers, but nothing is said about actual running  costs in the real world. Thus I contacted several of such people who had given me quotes asking what their customers’ real experience had been. After all the time in business, remarks that their systems had been checked by universities etc. they must have data and reports on running costs. Those with university connections have surely got the university to calculate averages etc. in given locations? The result? Silence. Absolute silence. With one I asked for the data by email as they must have it, I received a response it would be easier if I rung, so I did. When the chap I spoke to realised I was ringing with respect to my email he said he would ring me back as he was busy. Two weeks have gone by. No phone call.

I think the electric system is very good and much more preferable than a water based system but until someone can give me examples of actual running costs experienced I am hesitant to commit. Having said  all this if your property is smaller, an apartment etc. then doing away with a boiler and installing an electric system would make sense but carefully check what the running costs may be.

@G4RHL 

hi Richard

I have a simple view on this, an electric kW is the same as a gas kW.

If you assume a total efficiency for your gas system (choose a number, say 70%?  80%?) modern boilers are over 90% so I’m allowing for other losses) and look at your kW consumption over a year, then assume your electric system is 100% (it almost is, there will be losses in the wiring), then that’s how many kW you need for the same level of comfort/heat. 

The kWh cost of electricity is between 5 and 6 x  that of gas, so for that same number of kW (70 0r 80% of your gas kWh use or whatever percentage you choose) your bills will at least quadruple.

If the snake oil sellers have some other way of working out why it’s cheaper for the same comfort level and insulation I’d be interested to see it.

The only real saving is not having to run a pump all day (or for however long) circa 50 Watts

Tell me why that isn’t true?

There is no meaningful efficiency with an electric heater,  and most of losses with a wet system stay in the house. (assuming the system is reasonably well balanced).

You can’t get away from the physics. 

Thanks @woz that is how I was looking at it after listening to the various pitches I was getting. Lots of talk about how good they are, how simple the radiators are, and on that I agree 100%, but when you come  to pressing them a little on customers’ experiences of running costs there is a vagueness pervades over them as if suddenly in an alcoholic stupor. 

I understand the bottom line really is that with a good properly set up gas boiler, many are not, the loss is a little over 10%. Thus I used 16,725.50 kWhs with a natural gas one last year. and I would use 15,052.95 kWhs with an electric system. Currently I pay 14.015p per kWh for electric? That means a cost of £2,109.67 per annum for last year. Compared to my last year’s cost of about £459.88 for gas (without the membership fee).

My current boiler is old and inefficient. A new one will be better. But if my current efficiency is only 80% the mathematical proportions in the comparison remain the same. I might only use 15,000 kWhs with a new installation but with electric, it’s still a big number.

 

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