Heater only blows cold in 95 Caprice station wagon

[bigwar]

95 Caprice Station Wagon with a/c.

About 3 weeks ago I noticed no warm heat blowing out of the heater.
[This was before the big artic freeze hit us in the Northeast.]
Motor blows strong but no heat in any selection (def,floor,vents, etc.)
I checked radiator level: fine...

What could be causing this lack of heat?

[burnM]

Thermostat stuck open, Dirt on the a/c evaporator blocking flow of air, incorrect mixture of water/prestone,stuck valve on heater core hose.
Check those and see....

[bigwar]

Originally Posted by burnM

Thermostat stuck open, Dirt on the a/c evaporator blocking flow of air, incorrect mixture of water/prestone,stuck valve on heater core hose.
Check those and see....

Will do. Thanks.

[351c]

flush heater core with garden hose both directions

[oinkr2]

Here's another vote for flushing the heater core. These cars came with Dexcool and the factory added clay tablets to the cooling system. On several occasions the heater core on our 96 has become clogged. Take the hoses loose and gently flush both ways through the heater core and you should flush out the debris. Be sure to bleed the air from the system when you hook it all back up as a air pocket in the cooling system will give the same result and when you bleed the air out, don't let any coolant get on the optispark.