hi everybody,

i know this has been brought up 100's of times. I Drive a 2002 1.8 tddi focus and my heater doesnt work.

in more detail, i first noticed it a few weeks ago when driving through france, it was 34 degrees and when i pullled into a services the fan was rad running for 3 or 4 minutes when i pulled up. i was thinking with the heat that is out there it must be getting hot, so when i left the services i dropped my windows and put on the hot air, which stopped working after a minute, and only came back at a services.

Thermostat

so i assumed it was a thermostat stuck open, so i changed it, problem seemed to go away but after a long drive it came back, fan running again when i came into a services, and no hot air..... this time it was 2 degrees outside,

Airlock,

Im thinking an airlock is in the system but i cant seem to find it, also my thermostat seems to be allowing hot water through it the whole time so maybe the new stat is screwed again.

all help appreciated guys

airlock is one potential, the other is a blockage in the heater matrix, finally it could be a faulty heater resistor pack.

Sounds like waterpump impellor may have broke off.

ok, i had another look today, went for a drive and was getting warm air, as soon as i turned the blower up full it started getting cool again, this to me seems like an airlock, so to me it seems like an airlock in the matrix, blocked matrix or the water pump is on its way out,,,, as you guys said. Looks like a fun saturday is coming up for me. Any other ideas are welcome guys, negative temperatures are coming so i would like some warm air :P