NO AIR CON/HEATING

Check the handbook to see which fuses relate to the seats and heating then pull them to check for a blown one. Take 10 mins max and could be the cheapest fix you'll have.

There is a relay in the under bonnet fuse box for the heater fan, look also for the one for rear a/c, apparently doesnt matter if you have rear a/c or not the relay will still be there, swap them over and try the fan again, comes up quite often on the disco forum.

If you have a small amount of air blowing through the vents when stationary, I'd say there is a problem with the fan or power supply to it. I reckon the heated seats not working is a separate issue.

Col

agree in what @lynall said regarding the relay

first have u tried to reset the HVAC system

With ignition off press and hold the ECON & RECIRC buttons whilst turning ignition on (no need to start car).

The control module will then compare the current HEVAC actuator motor positions with the values stored in the module and will indicate an error by flashing the ECON LED.

If there are no errors, the LED will go out and the system will function normally.

To confirm that there are no errors, turn the ignition switch to the OFF position, then back to the ON position.

Observe the operation of the programmed defrost LED.

If there are errors present, the programmed defrost LED will flash and the system will attempt to calibrate itself.

plus doesn't hurt to get a code reader plugged in , always good to know if there's any underlying faults within the system