I have a 7kw Daikin heat pump, installed 3 years ago. It is controlled by a third party thermostat (ext RT). It was designed to be that way. I have the LWT set on weather dependant. Basically its on/off control. 

Now that the outside temperature is regularly below 10 C day, and 5 C night, it is becoming unaffordable to run. ( I'm retired and on a fixed income). I have read about running the system on LWT control and not using the room thermostat. 

In the settings I can alter from RT, extRT, LWT.  When selecting LWT,  it doesn't give options of what eco, comfort temps to run at, nor schedules. Plus, digging deeper, I'd have to change pump from request,  to sampling. Anyway, I gave up. Then I thought,  leave it on extRT, take it off weather dependant and set the LWT to 30C.

What resulted is the house warmed to 17.5C with stat set at 19C. I have now set LWT to 35C, and I'm warming up ok.

I'm fed up of tinkering with settings. I'm sick of the house being just "not too cold". I'm sick of needing to have a degree in mathematics just to stay warm in my home when the weather dips below 5C.

4 years ago I just had limitless hot water, turned the thermostat up if my bot was chilly. But that was my gas combi, I miss the simple affordable life.

I was told the world is going to burn, then stop spinning if I don't reduce my carbon footprint. The government then said gas boilers will be extinct by 2030. I thought I'd get ahead of the game and go green, save the planet and get an ASHP. I did just that. While my neighbours open their windows on the coldest of days to let out the heat of their log burners, I'm putting on extra layers so as not to go overdrawn at the end of the month.

On a side note. My house is up for sale,  I jest not. I had the energy performance certificate guy around to do his survey. A mandatory thing. He marked the heating system as poor, and the hot water system as very poor. Its just mindboggling how the government is pushing ASHP,  or why. 

Not many viewings to the house. I know it's bad time to sell, but it's because of the heating system. All the offers (it's a lovely detached house with lovely views over the valley) are way below asking price, to adjust for putting in a new heating system.

If anyone bangs on about going green to help the planet to spin, I'm going to buy a gallon of oil and burn it.

That turned into a rant. I just feel deceived and let down. If you're wealthy, great, go on keep this world spinning