Yeah tbh I think the way the Octopus model works; they are being very picky with what they want to touch. I have a 4M gap between my neighbor and I, and the surveyor despite still spending 3-4 hours here basically concluded with "it can't be done". Noise was the given reason...
Heat Pumps: anyone have one/thought about it?
- Thread starter fish
- Start date
Just shows how much insulation helps. We're in a 2017 build, used ~4,320kWh of gas for heating in 2024, and presuming a boiler efficiency of 85% means about 3,670kWh of actual heating energy needed. Our size is about 98sq.m, so scale it up to @TNA's house size and it becomes about 4,720kWh of required energy for heating.
Soldato
I suspect you will require a relatively large HP, large HWC and almost all of your rads will be changed plus more to be able to get the energy in the house. This quickly adds to the install costs.
Last edited:
Any reason not to get octopus guys to come have a look in person and give us a more detailed breakdown of what's what? My understanding is the £200 advanced payment is refundable up to 24 hours of the install date.
On a separate note, for now, is it worth me getting one of those heat loss surveys? Or maybe buy a camera myself use it and sell it on once done?
do they show you a break out - with hardware and labour to appraise it's accuracy ... like , are they replacing a hwt, radiators, their piping, how much the geography of the house and location of the components (long runs) impact the cost ?
plus do they give you any best & worst case electricity consumption too based on profiles of previous winters
That's quite a high quote from Octopus, effectively a £15k install pre-grant. That said I will not pretend to know what they take in to account, their pricing seems to have an air of randomness to it sometimes. But as others have said, 20,000kwh/year on the EPC is large.
I didn't have time to write mine up earlier here goes:
I've got a 140m^2 4 bed detached house built in 2003 with standard block/brick construction. The only mod to the fabric of the building since it was built was topping up the loft insulation from 100mm to ~300mm. It should have insulation under the ground floor, its got cavity wall and some very leaky double glazing. Our EPC suggests 9088kwh/year for heating which was not far our based on our gas bill.
Our house was heated by a power max range non-condensing boiler (only 14kw!) with integrated 100L heat store, it was very inefficient. The boiler heated the heat store which is pumped around the rads (vented loop) and a plate heat exchanger did hot water at mains pressure. All the rads are on 10mm plastic with 22mm flow and returns.
A neighbour has the above ripped out back in 2018/19, the system converted to un-vented, new cylinder, system boiler installed and it cost them £4k. I'd expect this to cost a lot more these days.
We got a quote from Octopus and it was £3,600, we paid for the survey but they didn't have anyone in our area right away so we had to wait a couple of months before we had the survey. The survey came and the heat loss came out at 5.5kw at -2.3C and they recommended a 6kw Daikin with 8 of 14 radiators needing changing which gave a total output of 5982w at 50C.
They had to come back and do a re-survey as we were not happy with the suggested location of the heat pump and the pre-work we would need to do to place it there. We re-located it round to the font of the house which was fine. We needed to block up the gas fireplace flue before they would install which I did by filling it with expanding foam (to be removed and bricked up when I get round to it). No one checked I'd actually done it but the surveyor said it added ~1kw to the heat loss so it was getting done regardless.
Our install look place in April, they supplied a few fan heaters to keep the house warm and I set up our caravan so we could have hot showers - happy days. The install itself wasn't without issues, they were meant to have arranged some scaffold as the installers were not certified for ladder work and after some ringing round that was organised for later in the week. They also sent a drip tray and we were meant to have a soakaway put in. The install team were fine, they were very polite and worked tidy. There was 5 or 6 of them on the job across the week and they had to come back at a later date and install the soakaway.
A few things I'd do differently if I did it again:
- Paid for trunking for the exterior pipework, I wasn't offered it and I didn't realise it was a thing until after it was installed.
- Paid much more attention to the pipework run, there they put it makes sense and it works but I would have preferred it going a slightly different route - that's my bad. I might move it one day if I get bored.
In Daikin land the 4kw, 6kw and 8kw are actually the same units, just software limited to the relative power level. The size above is a 9kw unit which is actually the same as an 11kw and 16kw unit which has been de-rated. The 4-8kw units can modulate down to 350w (input), the minimum the 9kw unit will go down to is 900w.
This is why it is really important to make sure you get the most appropriate unit. If you are slightly above the 8kw unit, it is a really good idea to add some more loft insulation to get you down to the 8kw unit because your performance on the 9kw unit will suffer because the minimum output is too high on the majority of days where it is not cold but not warm enough not to have the heating on (e.g. how December this year played out).
This is also the case with other brands - they only actually make a few actual units which are then software limited for the various sizes they offer.
No they have not seen the house, the quote is an estimate pending survey.
They usually stick to their quoted price but the price only covers fitting the heat pump, cylinder, pipework to and from the HP/cylinder, radiator swaps and electrics. Anything else needed on top of that is extra (e.g. structural surveys if required).
They don't break down the quote anyway even if you wanted it. When I priced up the main pieces of equipment, it came to half the bill and they had 5 people working on the job for a week - there is no way they made money on the job.
An estimate based on MCS formula will be on the quote post survey like all good installers should do.
His not wrong… when you go to other countries (both colder and hotter) they are literally everywhere.
They have been politicised here too and it is just dumb.
Edit: I also don’t know why air to air isn’t more popular, particularly in new builds which get incredibly hot and stuffy in summer. It’s is so easy to install fully ducted systems in new builds with zero visible plant inside. Also very cheap to install from scratch, far easier than wet system.
Last edited:
Soldato
thats looks like a total rip off
Octopus quoting me £4600 now for comparison. Still pretty high compared to gas.
Soldato
What you need to realise is the difference in quality, yes Octopus will work, but they aim for a flow temperature of 50c, which means a lower SCOP and higher heating bills although it would take a long time to save the difference in cost. It's also pretty clear Octopus are making very little money, if any. They are also very inflexible as well, it's their way or you go elsewhere, they will also turn away installation that don't fit their method.
If you want a top notch installation, then a Heat Geeks installer will do that, and should there ever be a design problem Heat Geeks are there to put it right, at their cost.
If you can afford a Rolls Royce, then why drive a Ford?
Obviously there is also a lot in between, I'm getting a Heat Geeks quote, had a chat with one yesterday, I'll also get a quote from another local installer, the likes of Octopus and British gas are the bottom of my list simply because I don't think they'll give me what I want.
If you want a top notch installation, then a Heat Geeks installer will do that, and should there ever be a design problem Heat Geeks are there to put it right, at their cost.
If you can afford a Rolls Royce, then why drive a Ford?
Obviously there is also a lot in between, I'm getting a Heat Geeks quote, had a chat with one yesterday, I'll also get a quote from another local installer, the likes of Octopus and British gas are the bottom of my list simply because I don't think they'll give me what I want.
Last edited:
I'd prefer a local quality company hence getting quotes, the Octopus price is just for comparison, I don't want to go with them but im not willing to pay for it at any cost, I will simply stick with gas. Flow temperature was 45c. At that cost I'd rather stick in a full a2a system and have change.
Soldato
My Heat Geek installer was 9.3k for a 5kw system, including all new radiators.
Soldato
@SpeedFreak presumably after deducting the £7500 BUS grant?