Exhaust Heat Pump: Why are my bill's so high?

I think that’s indicating the heating is on (unless the other screen which showed the “boiler” Element is also ON which would be the hot water immersion heater). 
I’ve found yet another web page for you !! https://knowledgebase.jouleuk.co.uk/uk/modul-air-user-manual You may already have this manual but it mentions the filter and the fact that it reduces efficiency if it needs changing. I’d get a new filter in now as you may find it lowers the running costs, especially in cold weather.

I think it was the heating trying to get the room up to temperature. But I thought the flat was warm enough already. 

Reading that manual, I'm wondering if the time and date is incorrect on it. I've also asked for the filter to be replaced. 

I checked the time and date and that was all fine.

​@nealmurphy just to let you know that I have a Joule Modulair All-E Exhaust Air heat Pump (EAHP)

​@joshantmann How is your heating getting on at the constant temperature setting ?

I'm averaging about £5.50 a day with it set on 18c for 24 hours a day. Does that still seem expensive to you?

It’s a lot better than £12 but it’s very difficult to compare to my system. I have 8 radiators in a 1970s bungalow and a different type of heat pump to yours. However the fact that winter months are much more expensive than spring and autumn remains the same, and of course in summer it’s only the hot water that needs heating. 
This graph from my Daikin app shows the kWh used over the last year, for heating and hot water, so the pattern will be similar for you. However I think some of your winter hot water heating might be done by the immersion heater (which is less efficient than the heat pump).

Recently the outside temperature was often below zero degrees C here in Surrey. Whereabouts are you and what outdoor temperatures have you had ?

Are you comfortable with the setting at 18 degrees indoors ? I’d find that a bit brisk !

It’s a lot better than £12 but it’s very difficult to compare to my system. I have 8 radiators in a 1970s bungalow and a different type of heat pump to yours. However the fact that winter months are much more expensive than spring and autumn remains the same, and of course in summer it’s only the hot water that needs heating. 
This graph from my Daikin app shows the kWh used over the last year, for heating and hot water, so the pattern will be similar for you. However I think some of your winter hot water heating might be done by the immersion heater (which is less efficient than the heat pump).

 

So are you just electricity in your place? Or looks like you're using, on average, about 16 kwh per day. Which seems very good, and what I think it should be paying in this modern, A rating efficient flat. 

I'm based near Wokingham. So very close to Surrey. 18c is not the warmest I'll be honest. I'm just afraid to turn it to any further in case the pricing goes mad again. 

In another post I mentioned if the wiring could be faulty in the flat, or something similar. My flat has its own front door with stairs leading up to the flat. At the bottom of the stairs are two switches....one to turn the light on by the door and another for the outside light(which doesn't work). Then at the top of the stairs are two switches...one for the hall and one for the light by the door. However, if you switch that light on, downstairs, then you can't turn it off using the switch upstairs. And vice versa. Surely this can't be right. Could this mean other things are wired incorrectly?

It’s a lot better than £12 but it’s very difficult to compare to my system. I have 8 radiators in a 1970s bungalow and a different type of heat pump to yours. However the fact that winter months are much more expensive than spring and autumn remains the same, and of course in summer it’s only the hot water that needs heating. 
This graph from my Daikin app shows the kWh used over the last year, for heating and hot water, so the pattern will be similar for you. However I think some of your winter hot water heating might be done by the immersion heater (which is less efficient than the heat pump).

 

So are you just electricity in your place? Or looks like you're using, on average, about 16 kwh per day. Which seems very good, and what I think it should be paying in this modern, A rating efficient flat. 

Apologies. 25 kwh a day. We haven't finished January yet.