XC60 D5 2010 Cooling System Service Required

[Symmo]

Thanks for all your replies.
I have done a few checks today.
1. I turned the car round to face uphill, to help with air bubbles.
2. Water level was just about on Max.
3. Ran the car on the drive for approx. 30 mins while logging coolant temperature with torque. Temp stabilised at about 45°C, I got it to 50 by revving it. Feeling the hoses to/from the rad, they were both warm/hot and about the same temperature. The rad fan was not running even at 51°C.
4. Temperature inside was 30°C which was a surprise. Was cold for a long time though.
5. Went for a drive about 5 miles on the motorway. Logged temperature dropped a bit due to extra airflow. No warnings from the car.
6. Back home, checked hoses again, coolant temp back to 51°C, fan was running, hoses were both same and quite warm. Water level had increased to nearly the top of the expansion tank.
7. There are 2 small bore pipes going to the expansion tank, one coming from top of rad and other from round the back of the engine. I think they are bleed pipes. I sucked both to see if any air was there. Coolant came from both straight away so no air there. I don't know where the coolant hoses to the heater matrix go so I couldn't check them but there is now warm air inside so assume it is ok.

This all seems normal to me. But the air temperature does feel lower than before, even though it is 30+°C.
I don't know if there is an electric heater , if there is, what fuse would it be?