A friend has an H-reg Peugeot 205 1.8 (I think) Diesel.
The heater only blows cold air. It has had a new radiator recently following a front end collision.
I suggested that the problem might be an airlock in the coolant, so we filled the expansion tank and then loosened its retaining bolts and tied it up to the bonnet so that it was above all the other pipes.
We found a bleed screw on the top heater hose and another by the thermostat housing. Opening these immediately led to coolant coming out of them, so we closed them again. We couldn't find any more bleed screws.
After running the engine until it was warm we felt the pipes. Both pipes from the thermostat housing were warm. The bottom hose from the radiator was cold. Both pipes going to the heater were cold.
Are there any other bleed screws hiding around the engine?
Is there any other way of removing an air lock?
If it isn't an air lock what could it be? Broken water pump, perhaps?
Thanks for any advice, At the moment the only advice I can offer him is to wear a thick coat while driving... David.