Heat Pumps: anyone have one/thought about it?

SkyTerran said:
Got a quote from Octopus for the following:
  • Daikin Altherma 3 Monobloc - 6kW (EDLA06EV3)
  • Joule Slimline 180L Cylinder
  • WARM K2 H700 x L600 radiator

    Are these any good?
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I have that heat pump, the 210l Joule slimline cylinder and two of the 700mm Height K2s in the kitchen.

In all honesty its been excellent. Ours was designed for 50C at -3C but it was far too high for our house. Our heat loss was 5.39kW and I run at something like 46C at -8C and its plenty warm. We had 9 radiator changes and run on 10mm microbore so yours sounds more suited than ours. The heat pump has been running on occasion overnight during tge last few days and the leaving water temp has been about 37C.

They managed to cram the slimline cylinder into our 600 x 700mm cupboard upstairs. Its barely warm in there as its so well insulated. We heat once per day to 48C and use about 1.2kW on average. Octopus did a great job too, the installers were spot on, even installing a radiator Id bought myself and making sure the CT clamp for the solar was repositioned so it could see everything. Id bite their hand off for £2k.
 
reef said:
I have that heat pump, the 210l Joule slimline cylinder and two of the 700mm Height K2s in the kitchen.

In all honesty its been excellent. Ours was designed for 50C at -3C but it was far too high for our house. Our heat loss was 5.39kW and I run at something like 46C at -8C and its plenty warm. We had 9 radiator changes and run on 10mm microbore so yours sounds more suited than ours. The heat pump has been running on occasion overnight during the last few days and the leaving water temp has been about 37C.

They managed to cram the slimline cylinder into our 600 x 700mm cupboard upstairs. Its barely warm in there as its so well insulated. We heat once per day to 48C and use about 1.2kW on average. Octopus did a great job too, the installers were spot on, even installing a radiator Id bought myself and making sure the CT clamp for the solar was repositioned so it could see everything. Id bite their hand off for £2k.
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Very similar experience with the same water temp target and similar flow temp so far though with a 4KW unit. I have adjusted my curve to 45C and -7C and will monitor as the temps go down. I also upped two rads in addition. I installed a bigger K2 in the main bedroom. The K3 I ordered online for the kitchen was huge and arrived on a crate! One of the plumbers helped me pick it up from my dads in his van and then modified the pipework to suit.

I've been adding addition insulation and draft proofing throughout the house. I also added additional lagging around my 180L hot water and volumiser tanks sited in the loft.
 
It’s also R290 rather than R32 so there are different install requirements.

The point I was making is that I can’t see Octopus picking up the Altherma 4 in scenarios where they can fit a Cosy because it completely negates the point of developing the cosy in the first place.

Personally if I was offered the choice, I’d pick the Daikin because you are not tied into octopus for support.
 
I've asked if Altherma 4 is going to be available any time soon.

If Octopus main motivation is to sell more electricity, they may not care much which brand of heat pump a customer buys. The surveyor said there is no price difference between Daikin 6kw and Cosy 6kw - if Octopus wanted to push more Cosys, they'd probably make them cheaper.
 
SkyTerran said:
I got a quote from Heat Geek as well, it was around 3.5K with a Vaillant arotherm 5kW, a Heat Geek cylinder and 38C design temperature. But there were a couple issues that put me off and I got this quote from Octopus - which I'll probably go with.
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For propane, higher temperatures are typically fine. Natural refrigerants handle higher temps and higher dTs much better than synthetic refrigerants.
 
Interesting that when I go to the Heat Geek web site and enter my address (3 bedroom end-terrace) I get this:

Estimated install​

Our estimated plan and price
£2,450
0% VAT
  • Includes £7500 BUS Grant
  • 340% guaranteed efficiency
  • Verified Heat Geek installer
  • Heat Pump icon
    Vaillant aroTHERM plus 7kW
  • Cylinder icon
    Re-use existing cylinder
  • Radiator icon
    1 radiator upgraded

And this is for a two bedroom mid-terrace:

Estimated install​

Our estimated plan and price
£1,950
0% VAT
  • Includes £7500 BUS Grant
  • 340% guaranteed efficiency
  • Verified Heat Geek installer
  • Heat Pump icon
    Vaillant aroTHERM plus 7kW
  • Cylinder icon
    Re-use existing cylinder
  • Radiator icon
    1 radiator upgraded

These are their prices for a 200L cylinder:

The 180L cylinder that Octopus quoted is a lot cheaper (but I guess it needs a bit of extra plumbing work and parts and it's less efficient) - only £609.50.
https://www.plumbnation.co.uk/joule...vented-180l-cylinder-trbmvd-0180sfc-404-11753

 
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Had a look at heatgeek. Looked decent at first for the 340% efficiency. Then you realise that it is without cylinder and price jumps to £4500.

Plus I just don't trust those guys tbh.
 
TNA said:
Plus I just don't trust those guys tbh.
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Why?

They are the only outfit in town which’s guarantees the performance of what they install.

That said I wouldn’t ‘trust’ anyone as the interaction is purely transactional but I doubt you’d find anyone more reputable.
 
SkyTerran said:
The surveyor asked me if I want Cosy or Daikin and I said Daikin. It looks like Altherma 4 is a lot quieter than the 3.
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Temps haven't dropped enough for my Altherma V3 to kick in yet so I manually bumped the target temp to let the system run. After a few minutes I had to get up, stick my head out the window to check if it had actually started! Very quiet as I usually only hear the water start to run round the system before it settles.
 
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b0rn2sk8 said:
Why?

They are the only outfit in town which’s guarantees the performance of what they install.

That said I wouldn’t ‘trust’ anyone as the interaction is purely transactional but I doubt you’d find anyone more reputable.
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Well I would trust Octopus a lot more. Every time I hear about heatable it seems like they overcharged.
 
For some bizarre reason, the Daikin occasionally seems to ignore the DHW schedule. It was supposed to heat at midnight but didn't and is stuck at 28C tank temperature. This has happened on a couple of occasions since it was installed in April.

Fortunately there's a free session coming up so I can just boost it on Powerful mode, but its really odd. There have been some reports of it on reddit and the Daikin facebook page and no-one can figure out why it happens.
 
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