Expert: John Kingery - 11/28/2010

Question
Hi just had a new thermostat installed and i,ve got no heat now, have tried bleeding with car jacked up got some air out, thought it would be ok but car still giving no heat when driving down road, needle just on top end of blue on dial, outside temp -1 any ideas have bled it enough!!!  

Answer
They're tough to "burp", but not that tough.  Sounds like you've bled it enough.  Possibilities include:

- Bad thermostat, or put in backwards.
- Bad heater valve
- Heater core plugged.

Check the heater hoses where they enter/exit the heater core (at the firewall).  Are the both hot?  One of them? Both dead cold?  This will help you pinpoint it.

Also, the 523 isn't available in the US, so don't know the exact configuration, but is the coolant hose on the output end of the thermostat housing hot?

Finally, I'm assuming that the heater worked before the thermostat was changed.