Overheating and no heat through Aircon.

Hi there,
I've recently had some issues with my A2 1.4 SE petrol.
Basically the car is overheating. I assume this is because the fan does not kick in unless the A/C is on. Further to my confusion is the fact that I've replaced the fan control unit and the wires don't seem loose, but still the fan isn't working.
Also, there is no heat in-car from the A/C.
Are the two connected, or is there something else wrong?

Thanks for any help you guys can provide.

There are several potential issues
Low coolant level due to overheating can starve the heater core of hot water (no warm air in the cabin)
The fan motor may be US (with climate control switched on the fan should run at slow speed as soon as the engine starts - even when cold)
Temp sensor which provides signal to the fan control module may be US
Motorised climate control air blending flaps may be stuck so only cool air enters the cabin

A diagnostic scan may highlight some of these potential problems

Cheers Spike

Hi, thanks for the reply.
The fan does indeed run when the A/C is on, but doesn't run at all when the A/C is off.
How would I go about checking the temp sensor is okay?
and how might I unstick the air-blending flaps?

Thanks again,
Cochin

Do you have the digital climate control panel with buttons and a LCD display to set the temperature, or rotary analogue dials?

I have the digital with LCD display one.