williams heater no heat??

[Tuccy]

hey all, thought id pop this on here to see if anyone can point me in the right direction...

My cars cabin heater is really rubbish, even on full heat with the engine warmed it only blows cold air..

i changed my thermostat and thats made no difference, also i flushed the coolant out and replaced it with a 50/50 mix water and antifreeze recently and thats not helped either...

have i an air lock maby ???
maby a duff thermostat???

any ideas much appreciated

thanks in advance
Thomas

[walters300]

sounds like the heater matrix could be blocked up or the selector wigit might be stuck on cold?