Electric Boiler with Underfloor heating costing a fortune

[Richvet]

HI Everyone, I have a large 3 bed 2nd floor flat which cannot have gas. I had it refurbished 3 years ago. I took the decision rightly or wrongly to install water piped underfloor heating with a 14.4Kw electric boiler. Sadly I did not project manage the job and the builders were not good at all. They never checked the floor levels before they installed the underfloor heating, and ended up cheating in two of the largest rooms by pouring latex over the top of the heating to get rid of the undulations in the floor. They have since gone bust:-(

My issue is the heating is so expensive to run. I am facing an annual electric bill of £8000 or more now, and that is with the cheapest supplier I can find. So I am looking at all of my options to try and reduce the cost.

 

I know I can improve the insulation in the apartment, as there are a lot of cavities around the walls, as being top floor I have vaulted ceilings in every room. Whilst the loft is fully insulated, the purchase of a thermal imaging camera as shown that there are big areas around the sides of most rooms which could not be as easily accessed, and were left by my lovely builders. But insulation aside, I need to try and find a more energy efficient way to heat my home as this is killing me

I have considered a heat pump boiler, but I do not believe I would be allowed to install the outside unit here as being a block of flats, putting anything outside is a no go. I have spoken to a heat pump installer who has informed me that the unit cannot be installed in a loft, even if I created a well ventilated area, as it still will not be enough air circulation etc. 

The boiler I have is slimJim (see link below), I am wondering whether there are other more efficient electric boilers out there, or are they pretty much the same? I am really struggling to think of any other options tbh, and wondered whether any of you guys who are much more knowledgeable might be able to help. I might freeze next winter if not!!! 



https://www.electric-heatingcompany.co.uk/electric-boilers/slimjim-electic-boilers/?gclid=CjwKCAiAyPyQBhB6EiwAFUuakt2EDYDZtRTPhzZ3ym_crE4Lz4C9swJ_SAN-VDW_ae9Li3hxhRprCBoCorUQAvD_BwE

[SteamyTea]

Problem solved, somehow.

Your post, when displayed in my phone was as I typed my reply.

But now seems fine. So shall go and read it.

[SteamyTea]

Basically electrical boilers are all the same. So no point looking for a different one.

Was any insulation put below your UFH? You may be helping to reduce your neighbours bills.

How large is this flat? 

You can get ASHPs that hang on external walls, would that be an option?

But if you are really heading towards £8k heating bill, even a third of that is expensive.

Can you fit PV on the roof?

 

Insulation, and airtightness are the way to go. As thick as you can get it.

 

Or sell up.

[JohnMo]

Heat during the night on cheap rate, as well Insulation etc.  Or ditch the UFH and install radiators

[Carrerahill]

Welcome to the electric future. 

 

Can you offset with PV?

[Radian]

1 hour ago, Richvet said:

But insulation aside, I need to try and find a more energy efficient way to heat my home as this is killing me

 

If gas and ASHP are not an option I don't think you can do this without tackling the insulation. This will probably mean biting the bullet and removing the plasterboard to access the cold areas you've identified - unless you have enough space to give up to fitting interior wall insulation over the top. But this would need re-lining anyway so it would make more sense just to investigate gaining access and fitting insulation behind existing. Also, the loft area - is it accessible? How much insulation does it actually have?

 

How long to you intend living there?

[TonyT]

A2A?

[RobLe]

£8000 is one heck of a bill.  My guesstimating makes that around 26MWh/year of elec, so I estimate 200kWh/day on cold days.  If you have actual numbers rather than my guesses, it would help!  I know Octopus "Go" and others offer cheap night time rates - I think 7.5p/kWh in a 4 hour window, but will cost more the rest of the time.  Interestingly, this cost is similar to gas (I know you can't get), and it's also similar to the new normal 30p rate divided by typical ashp COP.

You can get ashp where all the gubbins is indoors, a couple of pipes drilled through an external walls for air flow, might be acceptable?

Or simpler, using your present boiler, you could get 14.4kW*4= 56kWh/day cheaply.  Or likely a maximum of 100A*230V*4hours = 92kWh/day if you got storage heaters too, just time everything to operate on cheap rate only.  You can only get half the daily energy you need that way though - I agree with others, more insulation !   

[Richvet]

4 hours ago, SteamyTea said:

Basically electrical boilers are all the same. So no point looking for a different one.

Was any insulation put below your UFH? You may be helping to reduce your neighbours bills.

How large is this flat? 

You can get ASHPs that hang on external walls, would that be an option?

But if you are really heading towards £8k heating bill, even a third of that is expensive.

Can you fit PV on the roof?

 

Insulation, and airtightness are the way to go. As thick as you can get it.

 

Or sell up.

The underfloor had a thin layer of insulation, and then the thick pads that the pipes clip in to. Its concrete floor. I cant hang anything on the outside walls as my lease does not allow it. Landlord very fussy:-( in this block we are all in the same boat really. The flat is very large. probably clos to 2000 sq ft or so. 
I have suspicions that the dry lined walls have little or no insulation. I may be answering my own questions based on the current feedback so far here. But the attached image shows a corner of my lounge and the areas of concern for insulation
 

[ProDave]

So this flat is basically the roof space of the block if it is all like that.

 

Do you own it (leasehold?) or rent it?

 

There is nothing in principle stopping you insulating that properly but the work to do so is massive basically strip all the plasterboard off, insulate the frame / structure properly, replace plasterboard skim and paint.  Why would anything in the leasehold stop you doing that?

 

Do you have access to the small loft space above or is that not included in the lease?

 

This sort of issue with no or poor insulation affects a huge proportion of the UK housing stock and is harder to deal with in a leasehold property.

 

In all honesty, it might just b easier to move, and look carefully at the EPC when buying, and if you can avoid leasehold.

[Rob99]

The concrete floor is less of an issue if it is just the divider between you and the heated flat below. In fact you should be effectively benefiting a little from their heating.

 

Your issue is clearly those large uninsulated ceiling and wall areas, all your heat is just disappearing as if you had your windows open. If you don't want to move then, as @ProDave says, it should be possible to strip out and insulate properly. It won't be cheap but to be honest, properly insulated I'd expect you to easily save between £4 and £6k per year on your bills.

 

If you've just had enough of the place bear in mind that any buyer will ask about utility costs and the uninsulated areas would also be likely picked up on any EPC or home buyers survey so you'd probably be faced with accepting a much lower offer than you think it would be worth.

[Richvet]

53 minutes ago, ProDave said:

So this flat is basically the roof space of the block if it is all like that.

 

Do you own it (leasehold?) or rent it?

 

There is nothing in principle stopping you insulating that properly but the work to do so is massive basically strip all the plasterboard off, insulate the frame / structure properly, replace plasterboard skim and paint.  Why would anything in the leasehold stop you doing that?

 

Do you have access to the small loft space above or is that not included in the lease?

 

This sort of issue with no or poor insulation affects a huge proportion of the UK housing stock and is harder to deal with in a leasehold property.

 

In all honesty, it might just b easier to move, and look carefully at the EPC when buying, and if you can avoid leasehold.

Yes I cover the whole top floor. The flat is large which is both a blessing and a curse! The one across the way pictured is similar. 
My thoughts regarding insulation so far are
I can access the big void areas, as pictured in my message above, so was thinking of getting these all insulated. I know they are not great as food smells come up inside them from the flats below. Plus the amount of cold you can feel when near them is telling.
As for the main walls, which are all dry lined. I was thinking of getting the natural grain type insulation, which is completely safe and fire retardant etc. Then making holes in the dry lining around each room and filling them. 
Lastly, I have not been in the loft and surveyed properly yet, to see why the builder didnt take the insulation right to the ceiling edges, but am guessing access is blocked some how

This work will cost quite a bit of course. Not sure how much, but given the £675 I am currently paying Bulb each month, I would hope that I can recoup the cost quite quickly

I do own the leasehold of the flat, so insulating etc isnt an issue, but they will not allow anything bolted on the walls outside. I could sell and move, but I would not hide the massive heating issue from a potential buyer, so it would probably devalue the property to some degree

From reading the responses so far, it looks like insulation as best I can and go from there?

[Mr Punter]

I wonder if it would be possible to have some insulation blown in?  Could be cellulose or mineral wool.

[Richvet]

3 hours ago, RobLe said:

£8000 is one heck of a bill.  My guesstimating makes that around 26MWh/year of elec, so I estimate 200kWh/day on cold days.  If you have actual numbers rather than my guesses, it would help!  I know Octopus "Go" and others offer cheap night time rates - I think 7.5p/kWh in a 4 hour window, but will cost more the rest of the time.  Interestingly, this cost is similar to gas (I know you can't get), and it's also similar to the new normal 30p rate divided by typical ashp COP.

You can get ashp where all the gubbins is indoors, a couple of pipes drilled through an external walls for air flow, might be acceptable?

Or simpler, using your present boiler, you could get 14.4kW*4= 56kWh/day cheaply.  Or likely a maximum of 100A*230V*4hours = 92kWh/day if you got storage heaters too, just time everything to operate on cheap rate only.  You can only get half the daily energy you need that way though - I agree with others, more insulation !   

In terms of numbers for the last 41 days I used 634 day units and 140 night units. My provider Bulb is about to raise prices to 33p and 22p I believe and 38p per day SC

[Richvet]

2 minutes ago, Mr Punter said:

I wonder if it would be possible to have some insulation blown in?  Could be cellulose or mineral wool.

This was my thoughts yes. I can access from the inside by making holes in the dry lined walls, and the cavities can be access quite easily. This is the stuff I was thinking of. Ignore the price though, you can buy a lot cheaper elsewhere
https://www.travisperkins.co.uk/insulation-accessories/dupre-minerals-vermiculite-insulation-liner-granules-bag-100l/p/755408?gclid=CjwKCAiAyPyQBhB6EiwAFUuaku3gxdyeEoO97zWQjEalbkmO9PgzsiFxWv7D88OK4hIAKkyb70hCyhoCXrsQAvD_BwE&gclsrc=aw.ds

 

[Richvet]

1 hour ago, ProDave said:

So this flat is basically the roof space of the block if it is all like that.

 

Do you own it (leasehold?) or rent it?

 

There is nothing in principle stopping you insulating that properly but the work to do so is massive basically strip all the plasterboard off, insulate the frame / structure properly, replace plasterboard skim and paint.  Why would anything in the leasehold stop you doing that?

 

Do you have access to the small loft space above or is that not included in the lease?

 

This sort of issue with no or poor insulation affects a huge proportion of the UK housing stock and is harder to deal with in a leasehold property.

 

In all honesty, it might just b easier to move, and look carefully at the EPC when buying, and if you can avoid leasehold.

Yes I have full access to the loft. But as below, and potential buyer would need to be informed of the heating cost issue

[ProDave]

3 minutes ago, Mr Punter said:

I wonder if it would be possible to have some insulation blown in?  Could be cellulose or mineral wool.

That will be a cold roof so you have to leave some space for ventilating the outer surface particularly on the sloping bits.  Attention to detail when doing this is what makes it good or bad.

 

I would certainly make a loft hatch up into the roof space if there is not one already and have a look at what is there.  You might be able to look down into the sloping areas to see what is in there and how thick the rafters are,

 

The floor level eaves spaces should be made accessible with a trap door if not already and you can see what you can do there to improve things.  Detail is everything.

[Radian]

2 minutes ago, ProDave said:

The floor level eaves spaces should be made accessible with a trap door if not already and you can see what you can do there to improve things.  Detail is everything

 

Looks like those wooden shelving inserts might give easy access if screwed into place.

[Richvet]

4 minutes ago, Radian said:

 

Looks like those wooden shelving inserts might give easy access if screwed into place.

there are a few of them, but many do not have easy access sadly. So will be a case of opening them up and then having them repaired and plastered after.

[SteamyTea]

36 minutes ago, Mr Punter said:

I wonder if it would be possible to have some insulation blown in?  Could be cellulose or mineral wool.

Was wondering that.

 

35 minutes ago, Richvet said:

In terms of numbers for the last 41 days I used 634 day units and 140 night units.

What are your neighbours paying, might be useful to find out, just in case there is a wiring error, or you all want to club together and make the place better.

 

Your usage figures seem the wrong way around.

To give you an idea, on my much smaller place, this is what I have used this year (well 56 days of it).

 

Mean Power / 0.7 kW,

Percentage E7 / 89 %

Total Energy 924 kWh

Day Energy 106.4 kWh

Night Energy 817.6 kWh

 

That works out at 16.5 kWh/day (yours is 18.8), if I have worked it out right, that is £268.80 with meter rental and VAT.

Thankfully spring is just about here, so that will go down significantly.

Edited March 2, 2022 by SteamyTea

[Richvet]

10 minutes ago, SteamyTea said:

Was wondering that.

 

What are your neighbours paying, might be useful to find out, just in case there is a wiring error, or you all want to club together and make the place better.

 

Your usage figures seem the wrong way around.

To give you an idea, on my much smaller place, this is what I have used this year (well 56 days of it).

 

Mean Power / 0.7 kW,

Percentage E7 / 89 %

Total Energy 924 kWh

Day Energy 106.4 kWh

Night Energy 817.6 kWh

 

That works out at 16.5 kWh/day (yours is 18.8), if I have worked it out right, that is £268.80 with meter rental and VAT.

Thankfully spring is just about here, so that will go down significantly.

No the majority of my electric is used during the day, as I do not have night storage heaters remember. 

[PeterW]

I would take one of those shelving units out and I think you’ll be surprised as you will be able to get all the way along in the eaves I expect. First job, get PIR cut and fitted into the vertical wall panels from behind, and then work back and just roll back cheap loft insulation on the floor behind those walls and then leave it. 
 

The attic space, get up there and get 400mm of insulation up there, and then seal it and leave it. Not sure how old they are but I’m surprised that there isn’t min 250mm up there already. 
 

That will leave the skeilings which are a pain to do without stripping back but they are a small area so this should start to improve things. 

[SteamyTea]

2 minutes ago, Richvet said:

No the majority of my electric is used during the day, as I do not have night storage heaters remember. 

I appreciate that, just that your usage does not seem excessive, on a kWh/m² floor area metric, it is a lot less than mine (my place is 50m², and terraced).

Could you put in a thermal store and charge it at night?  It will be heavy, and large, but a possibility.

[Rob99]

55 minutes ago, Richvet said:

In terms of numbers for the last 41 days I used 634 day units and 140 night units. My provider Bulb is about to raise prices to 33p and 22p I believe and 38p per day SC

 Just done a quick calculation on this which works out as around £6.30 all in per day, which is similar to what I pay for a 200m2 1990's detached house. Nowhere near your £8,000 a year!

 

Clearly your £675 to Bulb every month isn't based on actual usage so first thing I would do is talk to them as it seems like they have their figures completely wrong (assuming your usage figures are correct).

[RobLe]

1 hour ago, Richvet said:

In terms of numbers for the last 41 days I used 634 day units and 140 night units. My provider Bulb is about to raise prices to 33p and 22p I believe and 38p per day SC

As ST says, that seems a lot less than expected, a total of 774kWh over 41 days, merely 18.9kWh/day.  Is that right?  It really isn't that much after all - if the figs are correct then your insulation is great, or the place is freezing!  Are they definitely right?

Even at 33p/kWh and assuming the same use 365 days of the year, a massive overestimate, that's still "only" 18.9*0.33*365 = £2280.

 

Do you have any other kWh figures - eg. yearly kWh consumption?  

 

I'm confused!