Sounds like a good plan.  I'm not sure whether auto adaptation will improve COP.  It may reduce flow temp from the WC curve under certain conditions but I think it will also bump it up when it's heating a room up. I'd be interested to know how it works for you. I've got a remote temp sensor  I've yet to set up, which will let me try auto adaptation. 

What's your DHW temp? That can make a difference especially if you use a lot of HW.     

Yes I’m unsure of the room adapt mode. Mitsubishi seem to push it as the best option but who knows. Agreed it may ramp up quite a bit from cold. 

Will run that vs WC for a week each and see how they perform

DHW was set to 48c but we now have Octopus Go 21:30-02:30 so I’ve set to 50c so there’s less chance of having to reheat the water in the day for kids baths etc. 

Running hot water off peak is amazing, I’m averaging about 25p per day for hot water 

trying to think of a way to utilise it for heating but all I can think of is to turn heating down between say 19:30 and 21:30 then Ramp it back up when off peak starts. But not sure it would much difference in the grand scheme. 

Something I have noticed since installing the official Ecodan remote controller is that when in WC mode, it will still turn the HP off if the target room temp is exceeded. I was wondering if the target room temp only worked in Room adapt mode. 

So currently on 25c flow via WC curve but room is 19c and target is 18c and heat pump has turned off after about 30 mins of running. 

I wondered if the return temp was just high enough but I set stat to 10c and it didn’t turn on all day  

So it looks like it’s intelligent and combines the signals. Is not just “on” with WC. Which is handy as it gives a bit more user control (ie I don’t have to explain to the Mrs why there’s a room stat that doesn’t do anything!)

now I just need to tweak the curve so it’s low enough to run most of the time. I’m trying to run UFH and oversized rads at same temp so I don’t need to blend the UFH down at the manifold. We shall see!

@benseb 

I thought that's how it worked and it's good to have it confirmed.  I might try and find a wireless controller.

@benseb

WC does not switch your heat pump on and off, it merely changes the required Leaving Water Temperature (LWT) that your heat pump produces. The heat pump will be switched on and off by the indoor temperature sensor, be it a thermostat or preferably an actual sensor.

Having read through the Ecodan manual in detail, though some time ago, my understanding is that Auto Adaptation uses both WC in conjunction with an indoor temperature sensor, to vary the LWT in response to both the changing outdoor temperature and also changes in the indoor temperature.

A good analogy would be trying to maintain a reasonably constant speed when driving a car up a hill. When reaching the start of the hill the driver will depress the accelerator pedal slightly in anticipation of the car starting to slow down, this is the action of WC. The amount by which the pedal is depressed will be dependent upon the driver's experience (weather compensation curve) of how much extra power will be required for this particular hill. It could be that the driver has in fact pushed the pedal down too far and the car starts to speed up, so an adjustment is made to regulate the speed. This is the action performed by Auto Adaptation, which adds to or subtracts from the LWT calculated by the WC.

I hope that this makes sense, but if not please question further.

@derek-m 

Thanks for the info. And yes understood. What I’ve observered though, which was not expected, is that if you have the official Mitsi remote room controller, in WC mode I wasn’t expecting it to do much, just follow the curve as you’ve said  

However the remote controller still lets you set the room temp in WC which I was expecting it to disable and “go dumb” or control The curve. 

What it does in practice is run off the WC curve but when the targetroom temp is exceeded by 1c it stops the heat pump completely which makes sense I guess as otherwise you’d have a completely useless expensive room controller unles you were in auto adapt mode  

Either way it seems room adapt works better than just WC as long as you have the official controller. Also on the proviso it may ramp up the heat a bit during a cold start. I’ve set the auto adapt to 30 mins so it should take a while to “ramp up” and with a night setback of only 2c hopefully that will be minimal  

Certainly seems a lot more “intelligent” than when I was using WC with third party stats. 

Another reason for ‘manufacturers controls only’. For owners of machines with non-adaptive controllers, the homely smart thermostat (it shouldn’t really be called that, but it is) will do advanced, continuous weather comp with load comp as as an option.

It controls the flow temp directly over modbus but only supports Midea and Samsung at the moment.

Been running heating for a couple of days on new simpler setup 

COP has been between 4 and 5. Last year was 3.3 at same time of year. 

Admittedly a very unfair test and at low usage but positive signs…

@benseb did you install the Mitsi room transmitter and receiver yourself ? I can see that I can buy a pair fairly easily but unsure what I need to do to connect the receiver to the FTC5.

@benseb can you explain what changes you made?

@hjd yes

its fairly straightforward

The receiver clips onto the control board, then you need to pair the receiver with the controller. Then there’s a dipswitch to change.