Heater problems

[steveiboy]

Hiya just recently changed my thermostat on my D2 heater was woorking fine  but now it is just blowing cold again  think it may possibily have something to do with water pump not working proper can anyone advise  it would be much appriciated

[disco_lew]

If it was waterpump .... You would have overheating issues! Myself i would say its either a blocked matrix or something on the heater box! Check that both water pipes going through the firewall into the cabin are warm/hot

[Frankie-Boy]

Sounds to me like you have an airlock in the system

[Hightower]

As Frank says, either an air lock, or not enough coolant in the system.  Only time mine went cold was when it lost coolant.

[Frankie-Boy]

I had so much trouble with my D1 and a cold heater at one point that I lost my temper with it and filled the header tank to the brim and drove down the road at high engine revs in low gear, it did actually work and got rid of the airlock I had, I wouldn't say it was the best way to do it but it worked for me, cleared the soot out of the exhaust too.