That’s very similar to the experience we had.
Surveyor elec company car and all…
Our info pack states 50C at -1.5C which is total tosh!
Here’s the weather curve we’ve evolved!
I presume the shallower the slope the more it has in decision resolution to draw on?
Might be totally wrong though or it’s a pretty blunt instrument in its calculation?
Today that gives us a steady state of
It seems to work right down to 25C output and then shuts off itself.
have you tried reducing the heating off at xx degrees c , mine is set to 14 degree outside temp and the heating shuts down
but agree i also have had to shallow of the curve quite dramatically
I’m
Still
Playing around a little bit , but never needed over 35 degree flow temps this heating season
design temp was 50 degree flow at -2.7
That’s interesting.
We had xx at 35/ -3 for a while during a mild spell, then it got too cold for that, but the slope was right.
Recreated the slope by dry wipe marker on the screen😂 but with a higher xx and much lower -.
Working pretty well.
It will of course never get to the upper temp!
one neat way to recreate the weather curve is in a spreadsheet. Here I am using google sheets, which also give me a version history for every change I make. Also makes it easy to check what flow to expect at any given outside temperature
Are they going to put in level 3 monitoring for you? I asked about it at survey (surveyor knew nothing about it, and had been in role for 2y). I then asked sales Jack about it, and it was a flat no. I might try again with the install team. I only need them to do the heat meter and then the power meters (I’ve got 2 direct-connect meters going spare from my PV inverter and EV charger which are being replaced with CT meters to tidy up the wiring). There’ll be plenty of space in the submain consumer unit, as I’m having a 22-way unit installed by my spark to replace the current 8-way EV unit. Octopus have agreed to use spare ways in this new unit instead of installing their own (subject to the final ok from their compliance people).
If my kit arrives in time yes. If anyone could recommend something that’s available that would be great.
I already have a circuit for the heat pump and external isolator in place.
How did you manage to get them to agree to install the monitoring kit? Is it because you had the PR team involvement? I’ve asked if they’ll install the heat meter if I supply it, but currently it’s a ‘no’ to 3rd party equipment.
I will ask and find out.
Maybe because I already have the isolator in place so no need for an electrician?
I got the numbers through today, for the Cosy 9 (9RH07 0101200001090). No technical data yet just this graph.
35C ScOP 4.36, 50C ScOP 3.6, 65C ScOP 2.99.
Seems like a decent jump in scop from the 6.
The issue seems to be with installing the heat meter on the flow and return primary pipe work. The electrical monitoring is easier to sort myself/my own sparkie, especially if using CT meters (direct connect can be a PITA).
Will the DN20 be suitable?
Slowly getting there.
Some new info:
“Minimum modulation for the cosy 9 is 3KW.”
Er, I hope that means it’s the minimum output not minimum input. Comparing it to my 9kW Daikin, that does 3.5kW-ish output minimum, 850kW minimum input.
That’s pretty high, assuming a COP of 4 that tracks in at 750W of input power.
Not much better than the Daikin 9kW-16kW units.
Getting technical information has been abit difficult, not quite setup for it yet.
That a very poor modulation unless it for a flow temperature of 30c when 20c outside. Both modulation (min output) and max output will depend on flow temperature and outside temperature.
Octopus refusing to publish data tables is putting me off the Cosy9 heatpump.
As an update, will get install date soon. There has been a bit of back and forth if the Cosy 9 has a door or not, it has a regular removable panel.
If someone could suggest what heat monitor I should get that would be great.
Cosy 9 install booked for the 6th.
Axioma DN20 and emonPI arrived.
Are they doing any rad swaps? Hope all goes well - I’m sure they’ll have their A-Team on your install. Are you using SDM120s or CTs into emonPi? What cylinder are they fitting?
No rad swaps.
We deliberately haven’t gone for the A team, but the install is as easy as you could get really.
Whole idea is to have a chuck it in system to compared with.
300L tank.
SDM120.
Hopefully the unit arrives beforehand so I can take a look inside without them around. 
Hehe.
They delivered ours on a Friday. Install started the following Monday..
Just make sure they fit the motorised valve the right way around!
We had one night of the Heat Pump thinking the house was the hot water cylinder!
Quickly resolved the next day..
As the underfloor heating / floor were stone cold and it was January, it warmed the house up nicely!
