No Heat ???? Nothing

[TDQ]

Two years ago my heat decided to stop working, nothing but cold air. Took it to the dealer...They said it needed a new heater core, $800.00.

Took it to another dealer, they looked at it, flushed it. It had slight heat...it was nearing the end of Winter so I figured I'd fix it in the Fall (Heater Core).

The next year came....Once again, I had heat, just like normal could cook eggs on the dash, never a problem all year.

Now, this Winter....Nothing, No heat, just blows cold air.

I have a hard time believing it is the heater core....Any suggestions (Changed the themostat)...possibilities...Anyone have the same problem???

[TDQ]

2000 Blazer by the way (TrailBlazer Package), 68000 miles.

[riptide44]

when you move the lever to defrost do you hear a movement under the dash and do you get heat here? same goes for when you switch to say .. floor heat you should hear the sound of the flapper moving - if not could be a problem with the vacum motor .

[frehol]

Is the heater core return hose warm? If not there is no flow thru the core... then you should back-flush it (again) and se if it works.

I had a leak in my core and it was not funny to change it, took say 6 hours...
/Freddy

[BlazerLT]

Blending door motor.

Do a search, the gear will often strip and the air will no longer be pushed through the heat core for heat.

Search for blending door.