Hi ​@Floascii ,

IIRC you must use the Mitsubishi controls only - third-party controls and Heat Pumps often don’t play well together.

Hi ​@Blastoise186 ,

Thank you very much for your fast answer.

I believe I would need a temperature measurement device in the living room. Based on my understanding and my model of heat pump, I would need the Wireless Thermostat PAR-WT50R-E and the Wireless Receiver PAR-WT51R-E.

Additionally, do you maybe know the difference between the new model PAR-WT60R-E and the old one PAR-WT50R-E.

Furthermore, I would like to be able to control the system remotely. To do this, I assume I would need the WiFi Interface MAC-5871F-E to use the MELCloud app.

Is this correct? 

I think so, but ​@M.isterW and ​@juliamc are more likely to know :)

You're correct, you will need the Mitsubishi wireless controller. I'm afraid I don't know the difference between the old and new versions.

You will need the WiFi interface if you want to use MELCloud but don't get too excited about. It's rubbish! It's fundamentally flawed in the way it controls the system and unless you have additional monitoring kit the data it shows is little better than a guess. All I use it for is switching the system to holiday mode when we go away.

TBH you shouldn't need to change the system settings once it is set up and running properly. If you play with the settings all the time you'll mess up the efficiency which is expensive.