1 Series Heater Problem

[sarap1978]

I have a problem with the heating in my BMW 116i. When the car is stationary the heater will work perfectly fine but as soon as I start to drive it starts blowing out slightly warm air. I can have the temp up to 28 degrees and it feels draughty. I’ve recently had the thermostat replaced and before this the heater worked fine. Any idea would be appreciated.

[Locknut]

Sounds like your new thermostat is a dud, new parts can be faulty too.