Mrs car (69reg Vignale) has been parked for last 2-3 months without being driven pretty much at all. (We normally use my other car). Very few times due to lockdown. 
when i drove today and wanted to turn on heating, to my surprise, I couldn’t get any warm/hot air even after 45mins driving (20miles). I checked coolant - and its between min and max.it blows only cold air, AC works but again for cold. ( I set on HI temp).
is there anything i’m missing? I thought maybe because car wasn’t used much but not after engine is properly heated, surely. Can i do anything myself to make it work or do i need to take it to ford garage (car is still under 2.5k miles). Thanks in advance.

Feel both coolant lines that go through the bulkhead into the cabin (with the engine up to temperature). The feed line should be pretty hot to the touch. If it's cold then you probably have air in the heater matrix that will need to be bled out.

Good morning from sunny Greece!!!

How is  car's temperature?

Does the indicator on the temp gauge reach the normal temp? If it does you have air bubble inside the paraflu circuit.

If it doesn't you might have to check your car's thermostat.

Sounds as though the control valve has seized shut. There is an electrically operated valve in the hot water system that is opened and closed rapidly and the ratio of time open to time shut controls the temperature. Dealer job. Their test gear will check the signal to the valve against expected temperature.

TBH if car is under warranty I would take it back. They may not be helpful but if you start tinkering dealer will be quick to blame you !

OPW ?