Thanks all for your replies.
I guess I am still in doubt. Octopus are now going to be re-surveying the property for suitability of the Cosy 9 - as apparently the survey for the Daikin is not suitable and they have to re-site it as it cannot be close to a drain (?), which the Daikin can.
Further, Octopus cannot install a system that can be cross-operated via solar and batteries for some reason.
Could you please advise on alternative non-octopus companies that you have good experiences with serving the east of England for comparison?
Any other advice on sticking with boiler, going with Octopus (low cost, but basic service), or going with a more expensive option, for example compatible with batteries?
I’ve started to hear good reports about British Gas heat pump installations (yes I know I can hardly believe it either).
They partner Samsung as well as Daikin and Vaillant.
My personal experience with a Samsung HTQ R32 has been excellent (local installer, who doesn’t serve E. England ). Might be worth talking to BG to see what price they could come up with, either for a Samsung HTQ (2-stage compressor so a competitive CoP) or their newish R290 series (back to single stage compressor maybe just different refrigerant properties allowed this…)
It likely just needs the current sensor for the battery unclipping and moving once Octopus are done. Octopus tries very hard not to touch any existing electricity installation so they don’t become responsible for it.
What the service costs and warranty like with BG, the high cost of getting service/warranty directly from Vaillant may wipeout the savings from a better COP.
We had a Daikin installed by Octopus last week and the electrician on the job made a point of asking if we preferred the heat pump to be visible to the solar/battery or not. (We went with yes please)
This was on a Powerwall installation so it was easy for him to put a new breaker in the Gateway and take the heat pump power feed from there.
Hi there. Take my advice, stick with your gas boiler! slightly different for us as we are off grid so have an LPG tank with the 2 year contracts that comes with. We moved to a 9kw Daikin last summer and it certainly hasn’t been plain sailing. It’s completely different, of course going from a Worcester Combi to an ASHP so takes some adjustment. Overall, cost efficiency is good but the Daikin app and controllers are completely NAF and not intuitive compared to the Hive we had before. In terms of overall comfort, its ok most of the time but struggled in the 3 really cold weeks we had, it just never really got the house warm during that period.
I could list a number of issues with Octopus. Overall they have been reasonable but clearly are becoming a victim of their own success and the upscaling of resources to meet demand has meant a reduction in service quality. On commissioning our ASHP started ‘smoking’ as they hadn’t bled the back up heater. It took three attempts ( and different staff) to balance our system. They installed the room stat in the small utility room with the hot water tank and only 800mm from a radiator so that had to subsequently be relocated to a colder room. The current issue relates to the hot water tank temperature falling by up to 10c when we have the heating on ( they think it could be a leaking 3 way valve and possibly the cylinder thermostat position relative to the immersion element powered by the eddi). I think they have been back around 10-15 times now so this has certainly affected our confidence in the system. Would I recommend an ASHP - not really, your home has to be super insulated and I think a hybrid arrangement would be better but you wont get the £7.5k grant for that!
(To cap it all, when the Daikin engineer came to renew the blown parts, he said it should never have been installed on the microbore system that we have
It’s good to read some of the interesting articles on here so thanks all!
Hi,
Just to offer a “one year later” post… we’re now pretty happy with our Daikin 9kW. The mis-configuration of the tape heaters was messing things up, but with that fixed and a lot of tweaking of the parameters (and working around the pretty poor Madoka thermostat…), we now have a comfortable house that has been cost effective to heat. We were always a bit tight with the gas heating, so the house temperature fluctuated a lot and never really stayed comfortable. Now things are much more “even”.
We have a Powerwall and use Intelligent Octopus Go, and averaged <12p/kWh over winter (including a reasonable amount of car charging). With a COP of 3.5ish, that can be thought of (simplistically) as less than 4p/kWh - handily beating gas prices.
Have you asked Octopus what it would take for them to offer you the Daikin 8kW? For example, we have a chimney that added to our heat loss - if we’d had that sealed we might have “qualified” for the 8kW…
Heat pumps do take a bit of getting used to - don’t let the house get too cold as it takes a good while to warm up. So that means running the heating for something like 20+ hours a day in a cold snap. The problem with the 9-16kW Daikins is the minimum power input is around 900W, which is quite considerable, so it’s usually not great to leave it running 24/7. So some adjusting of schedules or temperatures might be required. The smaller 8kW unit modulates down to around 250W, so can be more set-and-forget.
I can hardly believe it either).
). Might be worth talking to BG to see what price they could come up with, either for a Samsung HTQ (2-stage compressor so a competitive CoP) or their newish R290 series (back to single stage compressor 
maybe just different refrigerant properties allowed this…)