Should I get a new electric boiler rather than gas?


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Hi, my trusty Vaillant gas boiler (24 years old) is on its way out - not great timing of course but I am considering replacing with an electric boiler when we can. I realise they are a bit more expensive to run, but less maintenance and no new flue required. Plus of course, the electricity is from renewable sources.

Does anyone have any experience with electric boilers? In particular whether there is enough flow/pressure to run a decent hot shower!

Thanks in advance

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hi Al
I can't answer your question so apologies for this post in advance as it might waste your time reading it.

A bit more expensive? I suppose that depends on your annual consumption.

Looking at this practically, unless you have loadsa£££, perfect insulation and solar panels you do realise that every kilowatt used will cost you around 4 or 5 times as much as a gas kilowatt.
Assuming you use a similar amount of energy to heat your water and heating that means 4x the price for what you're paying for your gas now.
What about a ground source heat pump?

Also if you are going to lose the gas boiler it makes more sense to have local electric heating?

Plus the only way to partly mitigate is to use off-peak, which PP don't do.

Interestingly although by definition electric boilers are nearly 100% efficient (less minor heat losses) they are only rated as D for energy rating because they consume so much energy (C for hot water sometimes) - that seems strange and I never thought about it until I checked. It seems counter intuitive if you are using renewable energy but that's a discussion for another time.
There are ways round the shower issue, you would use (the installed storage system) and pump if flow was not to your liking
THIS will give you a starting point

later edit
it's interesting to note that the duty cycle for an electric boiler will be much bigger than for gas because the maximum output is very much lower than a typical gas boiler, you'll see the output is usually a maximum of about 1/3 to 1/4 of a typical gas boiler, plus if you go for the higher output ones your supply may not cope with it... and you'll need a very large cable to supply it (maybe 16mm). You may even have to confirm with your dno that it's OK and you'll almost certainly need a main fuse upgrade to 100A (there is no diversity to apply afaik).
I'm not trying to put you off by the way.


Al O;52518:
Hi, my trusty Vaillant gas boiler (24 years old) is on its way out - not great timing of course but I am considering replacing with an electric boiler when we can. I realise they are a bit more expensive to run, but less maintenance and no new flue required. Plus of course, the electricity is from renewable sources.

Does anyone have any experience with electric boilers? In particular whether there is enough flow/pressure to run a decent hot shower!

Thanks in advance
Thanks for your thoughts @woz, it certainly seems good on paper but when you explore the ongoing costs it may not be worth it at the moment. I noted in your post;

'unless you have loadsa£££, perfect insulation and solar panels'

I can confirm I have none of these things 😆

Unfortunately my house is land-locked so no chance of any ground heat pump either unfortunately. I'll continue to check into the direct cost comparisons but it feels like they aren't quite there yet in terms of comparable efficiency.

Thanks again,

​​​​​​​Al
You can use an air source heat pump. But they are a bit rubbish in the depths of winter...
We had another thread about putting green hydrogen into domestic gas supplies. But that’s not an individual solution either...
So, sadly probably not worth going electric at the moment.
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Hi al.
late reply but been doing stupid things to help out. Say no more.

my old oil boiler packed up and with modern building regs was going to be expensive and a lot of plumbing to move its location to conform. Circa 5k i installed an amptec flow boiler for circa £700. I also used some of the saving to install some green tech which helped lower the cost of my leccy bill overall.
running costs of boiler compared to oil were very similar so no increase in monthly out goings. Versus gas it will proberly be more for sure.
they can be set up to do heating and hot water. To run a shower you may need a bigger version but it produces instant hot water on demand.
install cost will depend on your current set up, hot water tank etc is a factor. Also need to check if you have spare capacity in your electric consumer unit as it will need its own 15 to 30 amp fused supply depending on size. And a new consumer unit to accommodate this extra fuse will a big expense to be consuidered.
overall i would recommend them.
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Very resourceful Jon1 and helping out sounds nicely rewarding - good work!
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And nice to see you back our Jonny! Your absence was noted 👍👍👍👍👍
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Its nice to be back our bevvy. And yes helping people is always rewarding.
hope everyone has stayed safe during my apparently noted absence, weird as i always feel no one notices when im not around.
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awww...I missed you!
Jon1;53065:
Its nice to be back our bevvy. And yes helping people is always rewarding.
hope everyone has stayed safe during my apparently noted absence, weird as i always feel no one notices when im not around.
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I ALWAYS notice people’s absences, deffo 👀
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Its good to be missed and I'm thinking wheres Lenny...
Thanks all,

That long Amptec boiler is very interesting @Jon1 - I'd looked at the Heatrae Sadia website as they are highly regarded, but I hadn't seen that type before.

Like your situation, If I were to replace with a gas boiler I'll need to make some changes to meet modern building regs but it would only be the flue moving and condensate pipe installing, rather than any gas pipework. I thought even that would be overly expensive but I've had some promising quotes through so far. Whilst using gas wouldn't necessarily be my first choice, it would still be better than the current situation as my boiler is so inefficient.

Al.
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Hello again al.

at the end of the day for most of us the cost is the ultimate decider, gas will always be cheaper than oil thats just the way it is. The leccy boiler is more efficient and will need less run time to heat the house once warm they will run at about 20-25% to maintain water temp and i also found that i could turn it on later than i was used to as its instant heat so that saves a few quid over a week.
sadly i feel gas will win out as running cost without self generation will be more than gas.
​​​​​​​at least its not winter when i gave up the goat.
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hi Al
The main efficiency hit is the hot flue gases heating the outside of the house, any internal efficiencies aren't as concerning as the wasted heat is internal.
You'll probably go from around 65%(depends on boiler age) to over 90% on the efficiency, but don't forget that's for the same boiler output. (in terms of the running cost). Personally I think it's best to err on the side of slightly more output, you can always moderate it with controls and it gives you the flexibility to change rads etc.
Al O;53176:
Thanks all,

That long Amptec boiler is very interesting @Jon1 - I'd looked at the Heatrae Sadia website as they are highly regarded, but I hadn't seen that type before.

Like your situation, If I were to replace with a gas boiler I'll need to make some changes to meet modern building regs but it would only be the flue moving and condensate pipe installing, rather than any gas pipework. I thought even that would be overly expensive but I've had some promising quotes through so far. Whilst using gas wouldn't necessarily be my first choice, it would still be better than the current situation as my boiler is so inefficient.

Al.
Fascinating read. An electric boiler hadn't occurred to me before. I am about to move into a house with oil-fired CH & HW. Would Elec be a potential better solution. It is a new build, so hopefully the insulation will be up to scratch as well.
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hi Ian
_​​​​​​​​​​​​​​It'll cost you a lot more to run than the oil boiler would.
​​​​​​​Have you considered a ground source heat pump?

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