No air source heat pump- what now??

Twoshoesnewshoes · 2025-10-09T16:48:51+00:00

Our oil boiler is on the blink, and I’m really keen to replace with a greener system. we have just had a survey from Octopus and they can’t provide us with an air source heat pump, apparently our house is too big! It’s not that big! they have sad we would need a 13kw heat pump which they don’t manufacture, as it would cost too much to run. don’t know what to do now. I had a quote for biomass but it was just so much money for so much hassle. ill look again at LPG… we will probably move in the next few years so don’t want to invest too much or get solar etc.

Justlovedogs · 09/10/2025 17:53

LPG isn't necessarily greener, I don't think? It's a by product of the oil industry so still fossil fuel.
I'm no expert, but if you're planning to move in a few years, I suspect your best bet would be to just replace the oil boiler.

Original poster

Twoshoesnewshoes · 09/10/2025 18:01

I believe LPG has arround 15-20% lower co2 emissions per kWh, but would cost more - around £400 a year for our usage,
we would have to replace our oil tank too, plus some other pipes etc, so will be around £3.5 k for the oil system, around 1.5k for LPG.

im gutted, I’ve researched for ages before landing on the ASHP

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pinkspeakers · 09/10/2025 18:09

Why can't you have more than one air source heat pump? We do.

Original poster

Twoshoesnewshoes · 09/10/2025 18:13

@pinkspeakers really? I didn’t know that was an option? Does it cost a lot to run both?

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MemorableTrenchcoat · 09/10/2025 18:15

Octopus is not the only supplier of heat pumps.

Original poster

Twoshoesnewshoes · 09/10/2025 18:17

@MemorableTrenchcoat no, and they suggested that I ask another supplier.
octopus currently don’t supply 13kw+ (which we would need) as they would just cost too much to run. I feel at least they’re honest about the issue!

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MemorableTrenchcoat · 09/10/2025 18:23

Twoshoesnewshoes · 09/10/2025 18:17

@MemorableTrenchcoat no, and they suggested that I ask another supplier.
octopus currently don’t supply 13kw+ (which we would need) as they would just cost too much to run. I feel at least they’re honest about the issue!

Electricity is around 4 times more expensive than gas, but heat pumps are 3-4 times more efficient than gas boilers, so the running costs should be comparable. And that’s without taking cheaper tariffs into account.

StillNiceCardigan · 09/10/2025 18:27

We got our heat pump from a local supplier. It's a massive thing! We have solar panels too so they offset some of the electricity costs. We sell back to the grid as well between April and October

CraftyNavySeal · 09/10/2025 18:29

MemorableTrenchcoat · 09/10/2025 18:23

Electricity is around 4 times more expensive than gas, but heat pumps are 3-4 times more efficient than gas boilers, so the running costs should be comparable. And that’s without taking cheaper tariffs into account.

Show quote history

What about heating water though?

It takes the same amount of energy to heat water regardless of how it’s done. My new flat has an electric water heater and it costs a fortune.

Octopus has cheaper tariffs but it’s typically it’s for things that can be done at anytime like EV charging because the times vary, not particularly useful for taking a shower.

MrsMattSantos · 09/10/2025 18:32

we’ve got a heat pump and it’s set to heat the water during the night - when the house is programmed to be cooler and we’re sleeping

Original poster

Twoshoesnewshoes · 09/10/2025 18:32

@StillNiceCardigan do you know the kw of your heat pump? What are your running costs in winter?
our quote for solar panels was around £15k so we really don’t want to install these if we’re moving in a couple of years.
but we can’t sell the house without a heating system!

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StillNiceCardigan · 09/10/2025 18:33

A heat pump will heat water more efficiently than an electric water heater because of the way they operate (the explanation is far too much information to convey in a short post) but its to do with inside/outside temperature differentials and so will cost much less to run.

MemorableTrenchcoat · 09/10/2025 18:35

CraftyNavySeal · 09/10/2025 18:29

What about heating water though?

It takes the same amount of energy to heat water regardless of how it’s done. My new flat has an electric water heater and it costs a fortune.

Octopus has cheaper tariffs but it’s typically it’s for things that can be done at anytime like EV charging because the times vary, not particularly useful for taking a shower.

Show quote history

A shower can be fed from a hot water tank, heated during off-peak times or perhaps via solar, as suggested above. As you say, using an electric immersion on a standard tariff is ruinously expensive.

TMMC1 · 09/10/2025 18:35

Avoid LPG at all costs. If you are intending to move in a few years put in a new oil boiler.

juggling1 · 09/10/2025 18:37

Octopus are well known for cherry picking the easiest houses. I expect you’ll have more luck with a different supplier. Try Heat Geek?

Daisymay2 · 09/10/2025 18:37

As PP have said there are other suppliers. However please make sure that you use a supplier with a good track record and have experience with installing them. It isn’t a straightforward switch. We checked on Which Trusted Traders and searched by ASHP suppliers with several years comments. Our supplier arranged for us to visit another customer with a house similar to ours in a rural area before we signed up.
we are 5 years in and it is great. And you can still get your electricity from Octopus.

Sailawaygirl · 09/10/2025 18:40

Try a local company. We got a heat pump last year and it was pretty straightforward for local supplier

Netcam · 09/10/2025 18:43

We have recently had a heat pump installed by Octopus.

We have moved the the Cosy tariff and set our water to heat during the cheapest times of day. It is about half the cost of the standard tariff during those periods.

We run the washing machine/dishwasher at those times too.

The weather hasn't been cold enough to have the heating on much so it's hard to tell overall it will be cheaper, but so far it's looking promising.

Octopus are quite fixed about what they will do, other suppliers will offer more flexibility.

Cyclistmumgrandma · 09/10/2025 18:43

We got our heat pump from a local supplier, as many others have. Octopus are not the only option.

Original poster

Twoshoesnewshoes · 09/10/2025 18:47

Thank you, there have been a couple of recommendations on our local WhatsApp group so I’ll contact them.
@TMMC1 why do you say avoid LPG? It’s quite popular round ‘ere, and I could get the bio LPG to cut co2

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XVGN · 09/10/2025 18:58

Check out the Gary Does Solar website and YT channels. He does suggest some local installers that "he has vetted". Heatble always seem to be recommended, but I have no experience myself.

www.garydoessolar.com

TMMC1 · 09/10/2025 19:05

Twoshoesnewshoes · 09/10/2025 18:47

Thank you, there have been a couple of recommendations on our local WhatsApp group so I’ll contact them.
@TMMC1 why do you say avoid LPG? It’s quite popular round ‘ere, and I could get the bio LPG to cut co2

Several reasons but the main one is you have no “buying power”. You can’t shop around like you can for oil. The supplier owns the tank and you rent it from them, this ties you into a contract with them as your supplier. If you want to change supply you have to end the contract and get another supplier to buy the tank and then you are stuck with them supplying you. There are also fewer suppliers.

Oil you own the tank and can buy from the cheapest place as and when you need.

I have lived in two properties with LPG and would never do so again. I wouldn’t even buy a house with it unless the price point worked to allow me to have the funds to switch to oil.

Original poster

Twoshoesnewshoes · 09/10/2025 19:46

Thank you
i have asked Ovo for a quote for an ASHP, a quick calculation suggests running costs of around £155 per month so slightly more than oil but not horrendous

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GasPanic · 09/10/2025 19:59

If you have large power requirements you probably have a large house.

If you have a large house you probably have lots of land.

If you have lots of land then maybe worth looking at a ground source heat pump.

GasPanic · 09/10/2025 20:01

If you are selling the house why are you interested in replacing the current system with a greener one ? It's all risk and no benefit.

Surely you just go for the low risk oil burner replacement and let the new people consider whether they want to be greener going forwards.