Compensation curve settings when using an Ecodan Air Source Heat Pump with under floor heating

I have had my Ecodan for 2 years now. I only have one ‘zone’, the house is set to 20C during the day and sets back to 19C at night. My understanding is that for heatpumps the set back is smaller than for a boiler. I found that if I set it back more it took too long to get the temp back up in the day.

My hotwater is set to 49C and is on eco mode (which I think is more efficient but heats more slowly). I switched of the ‘hysteresis’ setting and have the HW on a timer to heat up twice a day, at night and at midday (as I have solar)

The weather compensation curve is the most important thing. There are youtube vids showing how to program it and switch it on. The point is that the temperature of your CH hot water varies depending on how cold it is outside. For example mine is set at roughly 45 when its -5c outside, through to 32C when its 18C outside. The curve will be different for everyone depending on you house size, heatloss etc etc. You need to experiment, trying to get it as low as possible such that it still maintains the desired indoor temp

@Maurice Kelly  sorry I have a Daikin so cannot help with control settings. 

But, in general our ASHP is set to deliver 40 degrees at -2 outside temp, down to 30 degrees at +15. Our Nest thermostat is set to 22 degrees which is only needed when solar gain is high. I have also opened our TRVs wide open to get the flow rate up, leaving weather comp to do its thing, that way we get best COP out of the system.

At that curve setting we get about 19/20 degrees over 16 hours, all very comfortable and decent performance. 

I suspect you will already have a weather comp curve set within your controller, and it is just a case of changing the setting to switch it on. 

I just moved into a new property. 5 bedrooms upstairs and 4 big size rooms downstairs.  Big house but newly build. Pretty well insulated.  

Downstairs we have a zone with underfloor heating. Upstairs zone with radiators.  Ecodan Mitsibushi heat pump.  

My Electricity bill for January was over £600.  I am trying hard to figure out how to save costs.  Have changed the underfloor heating thermostat to 19.5 and upstairs radiators to 19.5.  

Both upstairs and downstairs swithces off for 2 hours when I go to bed as the sound of the pump makes it hard to fall asleep as it is by our window.  The rest of the time I keep the downstairs running with upstairs only switching on at 3am as I struggle to sleep if the bedroom is to warm at night.  Downstairs runs all the time except for the 2 hours around bedtime.  

The HW goes on 2 times a day to get to desired temp and the rest of it I try to keep fairly simple.  I tried experimenting a bit this week by lowering the air flow temp but then the house does not get warm enough and logic tells me the machine works harder.  So back to square one trying to find a solution that will keep the house comfortable but also cut cost. 

any advice or help with cutting usage would be much appreciated.