Discuss Electric boilers - how is this going to work. in the Electrical Forum area at ElectriciansForums.net

Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
? Thinking ahead a wee bit here, it looks like lots of people will be switching from gas combi boilers to electric combi boilers over the coming years. Most of the electric boilers seem to be around 12kW, while most of the gas boilers I've seen even in flats and small houses seem to be 30kW plus. So my main question is, how is replacing a 30kW + boiler with a 12kW boiler going to be sufficient to heat the place?

Secondly, what to do about about max demand? Many old domestic properties have 60A or even lower cut-outs, so how does that work with a ~50A boiler? Do we have to get the DNO to upgrade (in my past experience they are very reluctant to do so). And what about other large loads like showers? Do we have to fit some kind of selector switch so only one can be used at a time?
 

marconi

Respected Member
Messages
1,011
Location
London United Kingdom
I think we will see more ground and air heat pumps installed and instantaneous hot water systems in kitchens and toilets. Interesting thought about reservoirs of high potential electrons to cope with short term surges in demand. Or maybe families just pedal harder on their exercise bikes.
 

Midwest

Electrician's Arms
Messages
11,174
Location
Oxfordshire
Interest times ahead. We all tried electric heating in the 70's, and people started ripping them out in the 80's. My son lived in a brand new modern all insulated all electric 2 bed flat, recently. His fuel bills were higher than our 80's 4 bed place, and he only heated his bed & kitchen.

Ground,heat pumps will be fine for new builds, think there's some forthcoming building regs for that, but what will I do with my defunct gas boiler in 10-20 years time?
 

snowhead

Respected Member
Messages
3,610
Location
Mildlands
but what will I do with my defunct gas boiler in 10-20 years time?
Replace it with another gas boiler.
They aren't going to disappear, it's just that in the future new builds won't have Gas.

Heat pumps still need boost heaters to get water to 60, so it's unlikely the existing DNO network would support a street full of them.
 
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ferg

Electrician's Arms
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1,088
Location
N.W.Scotland
My understanding is the same as Snowheads.

It's only new builds and TBH they are so well insulated these days the heating load is much smaller anyway.

Also Electric boilers are shite from my experience but at least they are simple.

ASHP seems to be more common for new builds here.

This is of course based on my limited experience of them I don't do that many new builds.
 
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S

Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
Interesting conversation! An electric boiler is probably not would I would choose for heating an all electric dwelling myself. Storage heaters would seem to make more sense with an increase in renewables as they lend themselves to demand-side balancing.

But, I've been working for a boiler dealer doing the wiring for mostly straight-swap gas boiler installations & heating controls, and he's asked me (I think hypothetically) about replacing a gas combi-boiler with an electric, hence my question. So is the consensus that this will not work? That electric boilers are only suitable for highly-insulated modern buildings? In the short term at least this would just be a house here and a flat there so not likely to have a big impact on the DNO network, but for the individual supply and installation it might be more of a problem.

Marconi, when you say 'reservoirs of high potential electrons', in practice does that mean capacitors? Is such a thing available to buy for this purpose (can't say I've seen one in the Screwfix catalogue!).
 

Bellendian

Regular EF Member
Messages
199
Location
Gatwick
Generally the combis are 30+ kW in order to give decent hw flow rate. Electric boilers will most likely require a return to immersion tanks to even out electrical demand for hot water heating. A reservoir of high energy molecules...
Quite common to find system boilers in 12 to 18kW band.
 
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Midwest

Electrician's Arms
Messages
11,174
Location
Oxfordshire
Replace it with another gas boiler.
They aren't going to disappear, it's just that in the future new builds won't have Gas.

Heat pumps still need boost heaters to get water to 60, so it's unlikely the existing DNO network would support a street full of them.
Hmmmas Murdoch would say, not convinced thats going to happen
 
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Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
Generally the combis are 30+ kW in order to give decent hw flow rate. Electric boilers will most likely require a return to immersion tanks to even out electrical demand for hot water heating.
Starts to make sense. I mean, you'd never get close to 30kW with instantaneous electric heaters even with them all actually running and drawing current at the same time, except maybe in a mansion. So it seems like a system boiler and cylinder might be the way to go where an electric boiler is desired. The hot water could be set to run on low rate (night-time or when the wind blows/sun shines), while heating would be more on demand.

A reservoir of high energy molecules...
Think he's pulling our legs? ;):D:rolleyes:o_O

Quite common to find system boilers in 12 to 18kW band.
 

remedial

Trainee Access
Messages
69
Location
wales
its a similar situation to using a 10kw electric shower. its just not the same as gas boiler driven hot water system
 

Gavin John Hyde

Electrician's Arms
Messages
2,634
Location
Somerset
From personal experience I live in a 2014 apartment, the building is made of wood with a bath stone cladding.
the heating and hot water comes from a community heating system, they burn wood pellets on site and pump water to each apartment where a 'boiler' electric powered on a 16amp breaker reheats it.
my heating/hot water costs me between £20-22 a month.
This system apparently reduces the amount of energy lost in transportation and long cable or pipe runs.
I do think though that it wont be heating as we think of it now but will be a mix of solar powered, power wall to store excess and a modern version of storage heaters.
showers will be electric but there are new ones out there that operate at 20 amps which will be more than sufficient for most people. Think of ovens for years we were almost by habit thinking 40 amp and 10mm now im installing ovens on 20 and even 16amp breakers with 2.5 and even had one with a supplied 1.5mm cable.
things are going to change. necessity being the mother of invention and all that.
 

Zerax

Regular EF Member
Messages
127
Location
London
If they all had solar panels and storage batteries, that would surely help with the extra load...
That's the ideal solution... as in theory, if sized correctly, you could do away with your grid supply. I worked out the payback period of such a system for my place... but it was >20 years ! So at present, it's cheaper to use the grid supply.
 
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GeorgeCooke

Regular EF Member
Messages
484
Location
UK
The fact is that electricity costs 3 times as much as gas. I would never buy a new build without gas for this very reason.
 

sinewove

Regular EF Member
Messages
65
Location
shipley
From personal experience I live in a 2014 apartment, the building is made of wood with a bath stone cladding.
the heating and hot water comes from a community heating system, they burn wood pellets on site and pump water to each apartment where a 'boiler' electric powered on a 16amp breaker reheats it.
my heating/hot water costs me between £20-22 a month.
This system apparently reduces the amount of energy lost in transportation and long cable or pipe runs.
I do think though that it wont be heating as we think of it now but will be a mix of solar powered, power wall to store excess and a modern version of storage heaters.
showers will be electric but there are new ones out there that operate at 20 amps which will be more than sufficient for most people. Think of ovens for years we were almost by habit thinking 40 amp and 10mm now im installing ovens on 20 and even 16amp breakers with 2.5 and even had one with a supplied 1.5mm cable.
things are going to change. necessity being the mother of invention and all that.
Gavin,how can a shower drawing 20amps be sufficient compared with a 10kw shower?
Regards,S
 
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Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
From personal experience I live in a 2014 apartment, the building is made of wood with a bath stone cladding.
the heating and hot water comes from a community heating system, they burn wood pellets on site and pump water to each apartment where a 'boiler' electric powered on a 16amp breaker reheats it.
my heating/hot water costs me between £20-22 a month.
This system apparently reduces the amount of energy lost in transportation and long cable or pipe runs.
I do think though that it wont be heating as we think of it now but will be a mix of solar powered, power wall to store excess and a modern version of storage heaters.
showers will be electric but there are new ones out there that operate at 20 amps which will be more than sufficient for most people. Think of ovens for years we were almost by habit thinking 40 amp and 10mm now im installing ovens on 20 and even 16amp breakers with 2.5 and even had one with a supplied 1.5mm cable.
things are going to change. necessity being the mother of invention and all that.
Sounds fantastic! And very interesting regarding the technology in use. I'm guessing the solutions for new build and retrofit may well be quite different.
 
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S

Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
The fact is that electricity costs 3 times as much as gas. I would never buy a new build without gas for this very reason.
Even if the insulation and other efficiency measure meant you were using less than 1/3 of the energy?
 

PEG

Respected Member
Messages
4,870
Location
Manchester
Jeremy who?
Hi,Corbyn,is the Jeremy i was referring to...:)

....Just a sarky comment,alluding to the gentleman's rhetoric,regarding how we need to save energy and the planet,by investing in wind,solar,etc...and managing to ignore the enormous amount of energy,concrete,oil,copper,steel,minerals and magnets,such an undertaking,requires;)

Three of the world's most energy intensive,polluting materials,are in the above list...and no eco device i've seen yet,can be made or used,without them....unless it is an actual windmill...made from recycled timber,and only milling corn...that has had no input from chemicals,or fuel using harvesting equipment...or transport...(see what i mean?);)
 
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S

Selfmade

Regular EF Member
Messages
320
Location
Aberdeen
Hi,Corbyn,is the Jeremy i was referring to...:)

....Just a sarky comment,alluding to the gentleman's rhetoric,regarding how we need to save energy and the planet,by investing in wind,solar,etc...and managing to ignore the enormous amount of energy,concrete,oil,copper,steel,minerals and magnets,such an undertaking,requires;)

Three of the world's most energy intensive,polluting materials,are in the above list...and no eco device i've seen yet,can be made or used,without them....unless it is an actual windmill...made from recycled timber,and only milling corn...that has had no input from chemicals,or fuel using harvesting equipment...or transport...(see what i mean?);)
IMHO this is why we should have started the transition decades ago, replacing things like fossil-fueled power stations with renewable alternatives when they reached the end of their lifespan, rather than keeping on building them and then suddenly having to replace them all in one go at huge cost to the planet.
 

Zerax

Regular EF Member
Messages
127
Location
London
The fact is that electricity costs 3 times as much as gas. I would never buy a new build without gas for this very reason.
Yes... it's true that electricity is about 3 x more than gas on a per kWh basis... however once you factor in boiler efficiency, pipework heat losses, controllability, boiler servicing, breakdown cost etc etc... the gap does narrow quite a bit.

I know of a young lady who lives in a 2 bed flat with no gas... she pays on average £60 per month for electricity... which I reckon will come down to £50 once I've put some decent insulation in the loft. That's not bad really... and the flat was built about 14 years ago to building regs. (which are woefully low standard btw)

IMHO, right now there are two big drawbacks with electric heating... 1) Total lack of sensible, 'smart' controls to retrofit. 2) The nonsense of Economy 7... which, unless you make it way of life or religion, increases your electricity cost !
 

GeorgeCooke

Regular EF Member
Messages
484
Location
UK
I know of a young lady who lives in a 2 bed flat with no gas... she pays on average £60 per month for electricity... which I reckon will come down to £50 once I've put some decent insulation in the loft. That's not bad really... and the flat was built about 14 years ago to building regs. (which are woefully low standard btw)
So if she had and used gas it would be £20 a month, even better.
 

Zerax

Regular EF Member
Messages
127
Location
London
So if she had and used gas it would be £20 a month, even better.
errr... no
Due to efficiencies, service charges, boiler service and maintenance costs etc etc... it's more like £60 All electric vs. £50 with Gas/Electric... definitely cheaper with gas, but nowhere near the ⅓rd that you see with the basic kWh prices.
 

Tony Reidy

Electrician's Arms
Messages
118
Location
bedfordshire
? Thinking ahead a wee bit here, it looks like lots of people will be switching from gas combi boilers to electric combi boilers over the coming years. Most of the electric boilers seem to be around 12kW, while most of the gas boilers I've seen even in flats and small houses seem to be 30kW plus. So my main question is, how is replacing a 30kW + boiler with a 12kW boiler going to be sufficient to heat the place?

Secondly, what to do about about max demand? Many old domestic properties have 60A or even lower cut-outs, so how does that work with a ~50A boiler? Do we have to get the DNO to upgrade (in my past experience they are very reluctant to do so). And what about other large loads like showers? Do we have to fit some kind of selector switch so only one can be used at a time?
I have fitted a few the idea is to use them on economy 10 and not at peak time ok in a well insolated home
 

Tony Reidy

Electrician's Arms
Messages
118
Location
bedfordshire
? Thinking ahead a wee bit here, it looks like lots of people will be switching from gas combi boilers to electric combi boilers over the coming years. Most of the electric boilers seem to be around 12kW, while most of the gas boilers I've seen even in flats and small houses seem to be 30kW plus. So my main question is, how is replacing a 30kW + boiler with a 12kW boiler going to be sufficient to heat the place?

Secondly, what to do about about max demand? Many old domestic properties have 60A or even lower cut-outs, so how does that work with a ~50A boiler? Do we have to get the DNO to upgrade (in my past experience they are very reluctant to do so). And what about other large loads like showers? Do we have to fit some kind of selector switch so only one can be used at a time?
I have fitted a few the idea is to use them on economy 10 and not at peak time ok in a well insolated home
I have fitted a few the idea is to use them on economy 10 and not at peak time ok in a well insolated home
Insulated
 

Tony Reidy

Electrician's Arms
Messages
118
Location
bedfordshire
? Thinking ahead a wee bit here, it looks like lots of people will be switching from gas combi boilers to electric combi boilers over the coming years. Most of the electric boilers seem to be around 12kW, while most of the gas boilers I've seen even in flats and small houses seem to be 30kW plus. So my main question is, how is replacing a 30kW + boiler with a 12kW boiler going to be sufficient to heat the place?

Secondly, what to do about about max demand? Many old domestic properties have 60A or even lower cut-outs, so how does that work with a ~50A boiler? Do we have to get the DNO to upgrade (in my past experience they are very reluctant to do so). And what about other large loads like showers? Do we have to fit some kind of selector switch so only one can be used at a time?
Just get a blanket
 

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