Home central heating & hot water needs to be upgraded - what should we be thinking about moving to? 18 March at 7:15PM in Energy 21 replies 989 views

TemmyTemjin

Hello,

We live in a rural village without any gas connection. Our heating is done via an oil boiler (as are the majority of people in the village). The boiler and whole setup in the house is archaic, and I want to plan for replacing it.

My understanding is the government want to ban the sale of new oil boilers in 2026, and this has me wondering if it's worth the £xxxx;s to overhaul the house for a new oil boiler.

As much as air source heat pumps keep getting pushed, I believe our house is simply not viable for one (uninsulated concrete floors, no underfloor heating...etc). I don't see how one could operate in any effective way.

If oil is going to be banned, and an air source heat pump isn't viable, what options do we have?

Thanks

Belenus

TemmyTemjin said:

If oil is going to be banned, and an air source heat pump isn't viable, what options do we have?

Calor Gas or similar.

Wood pellet or similar boiler. Could be cheaper than oil.

Ground sourced heat pump. Like air sourced may not be viable.

Electricity. Very expensive.

There may be other options.

Can you improve the house insulation?

tacpot12

If electric is viable, a heat pump will save money. Modern heat pumps will be two to three times as efficient as direct electrical heating, and can be more efficient if set up well. 

Heat pumps can be viable with a well insulated house and with large radiators; underfloor heating isn't necessary. Any improvements you make to insulation will save you money regardless of the heating you eventually choose.

markin

Boilers last 15-25 years, upgrade now and you don't have to think about until you can't get parts anymore.

Spoonie_Turtle

We have a moderately well insulated property but I don't think the floors are, our EPC rating is D67.  Our heat pump so far has been working with an efficiency of c.260%, that was with the default installed settings (for always having heat rather than efficiency), thermostat set at 18℃, water at 50℃, always on and a weekly legionella cycle which uses the immersion to get up to 60℃.
I've since discovered our model has a vampire load in summer, 35-50kWh/month for 'heating' with 0 output - take that away and the efficiency might be nearer 300%, same for the legionella cycle.

We have since tweaked the settings as well, midway through September, and November to February it's been over 300% efficiency overall - 375%, 300%, 320%, and 345% respectively.  And that's without using the weather compensation curve which is supposed to be the most efficient way to run them.  Plus we have the weekly legionella cycle still, *just* in case. 

We have yet to find out how it goes for overall efficiency over a year with the new settings, but considering this is an old house, the exposed north side of the semi-detached building on the top of a hill and seems to get quite cold (our heating at 18℃ kicked in halfway through September, when other people were still reporting temps of 19 or above without heating!) and not the absolute best insulated it could be, I don't think those efficiency stats are too bad.

So I wouldn't dismiss the idea of a heat pump because of your floor, although if the house is overall badly insulated then whatever method of heating you choose will be more expensive than if you can insulate your house better.

Of course heat pumps struggle to be on par with mains gas for cost per kWh, at the moment it is possible to get oil cheaper per kWh than even mains gas, and the ban of selling new oil boilers doesn't mean you can't fit one before the ban.  But nobody knows which way the cost of different fuels will go in the future, and there's the upfront costs to consider too.  I don't envy you needing to make a decision - the Housing Association foisted the pump on us so we had no say in it, and nothing to decide!

Reed_Richards

An Air Source Heat Pump is a heat source just like an oil boiler.  If you can get enough heat our of an oil boiler then you should be able to get the same amount of heat out of an ASHP.  So it makes no sense to say an ASHP isn't viable and to leave it at that.

If it costs you a lot to heat your house already using oil then you might need an ASHP that is larger than the average one.  As such it might need planning permission and it might be particularly expensive if it exceeds the standard range.  ASHPs use lower water temperatures than older oil or gas boilers so you might well need new, larger-area radiators.  And at current fuel prices an ASHP is likely to be more expensive to run that an oil boiler.  But it would work.

I replaced my oil boiler with an ASHP.  My house was built in 1980, the insulation is okay but not great.  I also have concrete floors with just an inch of polystyrene for insulation underneath them.  My ASHP works fine and I'm pleased with it.  It's just a bit annoying that since I bought it the price of electricity has risen by a much larger percentage than the price of oil.         

FreeBear

Reed_Richards said: If it costs you a lot to heat your house already using oil then you might need an ASHP that is larger than the average one.  As such it might need planning permission and it might be particularly expensive if it exceeds the standard range.

If the heat pump is particularly large, you may well need a three phase supply - That is only going to push the cost up.

Spend as much as you can on thermal improvements (insulation, doors, windows, killing draughts, more insulation) and get the heat demand down.

CalJo99

What about a log burner? It's carbon neutral (as in, it burns the wood that has soaked up carbon). Wood is usually pretty available in the countryside, even if not from your own garden, then other people's (eg, you can offer to hack back woody vegetation for them etc), or simply buy it from anyone who is chopping down a tree etc (or is brought down in storms).

(If you get a log burner, get one with a flat surface, that way you can keep a kettle of hot water on it, like keeping it on an Aga!)(cuts back your electricity cost for boiling a kettle!) Keeps food hot too.  You'll need to put the utensil/kettle on tin foil, or with a roasting pan underneath it, so as not to mark the top of the log burner.)

Log burners can be connected into heating water, but I think that's considerabliy more complicated and expensive.

Of course, if you want heat throughout your house that's more a call for central heating systems.

I still like oil - especially because once the oil has been purchased, then you get 'free heat' thereafter. No bills arrive....

I have a combi oil boiler, that gives me instant water, on and off, whenever I want it (OK, takes longer to fill a bath without a tank). Rads heat quickly too.  Rads are brilliant for drying washing in winter. 

If you go for a new oil boiler of any kind, you'll need to think about where you oil tank is. I 'think' (others know better??) that currently, exisiting oil tanks that sit almost against exterior walls can stay (???), but a new one will need to be away from a dwelling/structure by about 2 m (??) and set on concrete (I don't think they need to be raised????). Just finding somewhere that meets that condition can be tricky, depending the size of the garden/plot, and you'll need to dig a trench or whatever for the pipe connection to the house?  (A fireproof tank can, I think (???) be set against a wall, but they are pretty expensive???)

So, anyone installing a new boiler may require you to move the oil tank away from the side of the house as well??? Or, at least, will require you to sign off their work and take liability yourself.

This, I understand (???) also applies to LPG systems. 

As for electric CH, I know of someone who has, effectively, a 'kettle' under the stairs which heats the water that fills the rads. It is limited in range from what I understand (as in, they can't have that many rads running hot at any one time, the 'kettle' can't heat enough water).  The cost, of course, goes along with the cost of electricity, but on the other hand, 'one fine day' we may all be solar/wind generators ourselves??  So 'eventually' an electric heating system could well become green (plus of course renewables via the e-grid nationally)

If your hot water tank is a long way from your kitchen sink (depends on the size of your house!) you can also have a 'kettle' heating system placed under your sink to give you quick hot water for washing up etc, and that won't waste hot water brought all the way down from a distant hot water tank.

I know heat pumps are fashionable at the moment, but the capital cost seems punitive to me. Will this come down? Will their efficiency go up? I think it's early days still. 

With any heating system it's always a balance between the capital cost of installation, and the eventual savings in cost of ownership and use. How long will it take to recoup the capital cost?

Good luck with it all. It's a pig of a problem alas.

Reed_Richards

FreeBear said:

Reed_Richards said: If it costs you a lot to heat your house already using oil then you might need an ASHP that is larger than the average one.  As such it might need planning permission and it might be particularly expensive if it exceeds the standard range.

If the heat pump is particularly large, you may well need a three phase supply - That is only going to push the cost up.

Spend as much as you can on thermal improvements (insulation, doors, windows, killing draughts, more insulation) and get the heat demand down.

Good point about the three phase supply, I forgot about that.  And your point about improved insulation and draft elimination is good advice in almost every context.

It would be useful if the OP could tell us how many litres of oil they use per year, that would provide useful context on which to base our advice.

70sbudgie

CalJo99 said:

If you go for a new oil boiler of any kind, you'll need to think about where you oil tank is. I 'think' (others know better??) that currently, exisiting oil tanks that sit almost against exterior walls can stay (???), but a new one will need to be away from a dwelling/structure by about 2 m (??) and set on concrete (I don't think they need to be raised????). Just finding somewhere that meets that condition can be tricky, depending the size of the garden/plot, and you'll need to dig a trench or whatever for the pipe connection to the house?  (A fireproof tank can, I think (???) be set against a wall, but they are pretty expensive???)

So, anyone installing a new boiler may require you to move the oil tank away from the side of the house as well??? Or, at least, will require you to sign off their work and take liability yourself.

This, I understand (???) also applies to LPG systems. 

My Dad did this perhaps 10 years ago. The (original?) oil boiler needed replacing in his 1970s detached house. On assessment it was identified that the oil tank also needed replacing and would have to be relocated away from the garage wall. So the total upfront cost meant that a heat pump was a financially viable option. 

Due to a large south facing solar array, the running cost of the heat pump was also significantly lower so the payback of the difference in cost between a modern oil replacement and the heatpump was less than 5 years (I believe). 

If I had known then, half of what I have recently learned about heat pumps, I would have really enjoyed tinkering with the system to improve the efficiency. 

Edit to add: I am not aware that my Dad had to upgrade insulation or radiators. But without the grants now available, the installers seemed less fussed about providing a "viable" system. They just designed a system that worked as replacement to the oil boiler.

macman

It's not a ban on 'new oil boilers'. It's a proposed ban on the installation of oil or gas boilers in new build properties. No restriction whatsoever on replacements in existing properties, which will still be happening decades from now.