Ford Mondeo heater problem

[chyryn]

My M Reg Ford Mondeo Diesil heater will not blow Hot. Blower works fine, I have flushed and back flushed the heater matrix, strong flow and clear water. I have changed a dodgy thermostat but still no hot air. On removing console panels I can see the Temp dial operating a gear toothed cam with no restrictions. Where do I go from here? Can a broken water pump cause this problem?

[homer75]

Sounds like an air lock. There may be a bleed screw on one of the heater hoses ( flow and return from heater matrix) back of the the engine where the pipes run thru the bulkhead. If no bleed screw, pull off hose and let air out of system while running the engine.

[madein1978]

On the MK1 Mondeo like yours, the hot and cold air is controlled by an electrically operated flap, see if this is working, if not, theres your problem. If you had a knackered water pump the engine would get hot very quickly as there would be no flow. Feel the heater pipes when the engine is at running temperature, if they are both hot then you don't have an air lock. I would be inclined to look at those heater flaps, cos I think your problem is here.