How would u normally get shut of an air lock
air lock - take the small hose off the thermo housing and the header cap and leave it running till warm, or till water starts comming out the thermo housing.
Fan has been working but failed to kick in last night when it started to expand the header tank. This is what lead me to believe the new thermostat had faild because the fan swithch is the other side of the stat housing?
Sounds like everything is new, is the fan switch new? i'd be looking into the fan problem, try bridging the connection to the fan, remove the blue plug on the side of the thermo housing and use a couple small screwdrivers or something in the connector holes, this will bridge the fan and it'll kick in if it's working (have ur ignition on
) If it works look at replacing ur fan switch as well as getting rid of any air locks