F40LM

All of sudden no heat.

I have checked the servo arms above the gas pedal, and have watched them rotate from one position to another. Look good to me.

I know that air in the cooling system can cause no heat but the cooling system has not been opened recently at all. Carrunning fine other than no heat from the vents.

Advice needed....what do I check next guys?

Thanks for looking.

michael

F40LM

Bump....come on folks....it was 40 degrees this morning.


michael

kombatrok

heater control valve? That would be my guess

andys-944

I think you checked the control valves that was my issue happened twice first time the old unit had crumbled then last year the new unit came un hooked, so it was still moivng just not operating the valve,simple fix.
When you saw it move that was as a result of turning the temp on the thermostat control up? so the control unit is working?
Is the fan heater fan running?

F40LM

Thanks guys. After your two postings I did a search for the heater control valve and came across these pics from a prior thread.

Yep, looks like about two weeks ago when I was playing around with the speed and referance senors I must have knocked it a little loose. It then came out of the little housing a few days ago. Mystery solve. Just don't know much about the HVAC on cars. Took me :30 seconds to fix now that I knew what to look for.

Thanks again. And for those like me who need them here are the pics showing the location of the valve.

michael