@njt Oh Dear!😩 That's not good news at all! Toodles.

Posted by: @njt

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Unfortunately Octopus won't fit it on the heat pump install, and Homely say the only sell to installers, so there's the problem.

Not sure if there's a bit of talking at cross purposes going on. You appear to be interpreting that as "Homely will only supply their box to whoever installs your heat pump". My interpretation is "Homely kit needs to be installed by someone professional, so they will only supply to businesses registered as Homely installers".

If I'm right, there would still be no problem since you could get the kit installed after the fact. In practice, I can't see why that would be a problem either since the only physical fun and games is with a bit of modbus wiring and that's not would need to be done when the heat pump is commissioned.

@majordennisbloodnok Installation involves connecting (on the Daikin range anyway) two wires to P1 and P2 within the existing control box / or straight to the heat pump connections. The modbus connects to the Homely controller and there are some switches to be toggled in the modbus itself. Homely provide the details of switch positions and the PSU’s to power the Homely and the modbus itself. There is a configuration programme which you initiate via their app and after some 30 minutes, Homely will start to take over all the control. The modbus I have is a D. Comm unit. Regards, Toodles.

Posted by: @toodles

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@majordennisbloodnok Installation involves connecting (on the Daikin range anyway) two wires to P1 and P2 within the existing control box / or straight to the heat pump connections. The modbus connects to the Homely controller and there are some switches to be toggled in the modbus itself. Homely provide the details of switch positions and the PSU’s to power the Homely and the modbus itself. There is a configuration programme which you initiate via their app and after some 30 minutes, Homely will start to take over all the control. The modbus I have is a D. Comm unit. Regards, Toodles.

Precisely. Thanks, @toodles, for confirming.

Making use of a physical modbus connection is not unique to Homely and is just an add-on bit of config that can be done at any time after the heat pump's commissioning. As long as @njt can get Homely to put an installer in touch then I see no issues whatever with their kit being installed completely independently from Octopus' work.

Posted by: @njt

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Oh, and they wouldn't entertain doing a system design less then 50 Deg, even though I'd read somewhere someone got a 45 Deg design off them

@NJT, same here with my experience. 50degC design, which at the time I didn't query. But the same set up is now set to 45degC max, and most of the time sits between 35 and 40degC. 50degC does get rather thirsty on the power consumption, but an EPC B home probably won't require it if you run low and slow with all day space heating.

And one more thing, my Homely was a retrofit job as the firmware for the Daikin had not been created at time of installation; I had a NeoAir stat just set several degrees higher than required at first and used the heat pump’s parameters to control the heating comfortably. (I’ll own up to some degree of tweaking during this period though 😉) Regards, Toodles.

@allyfish 

Thanks. 

I'm just waiting for a date now for install, I signed last week. 

I'm hoping for what they told me, 4 to 6 weeks. Definitely don't want to be installing winter time. 

I'd rather have some time before it gets really cold to get used to everything.

Posted by: @allyfish

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but an EPC B home probably won't require it

House heat required or EPC rating, is not what defines flow temperature, it's related to radiator size and flow temperature and the combined output in kW.

A bigger heat demand, at the same flow temperature, just requires bigger radiators. A smaller heat demand just gets smaller radiators.

If you design a system for a flow temp of 50, it just means you can get away with smaller radiators instead of big one suitable for the correct heatput at a lower flow temperature.

All heat pumps should be run low and slow. Trouble is when systems are designed for 50 Deg flow temp CoP is poor, doesn't matter is it's an EPC A or F, it's just rubbish.