Heater problems...

I have a 1999 Blazer. The blower works...the A/C works, but the heater does not blow out hot air. I change the thermostate and now I don't know what else to do...anyone know what I should be checking?

Thanks

could be the heater coil....?

did you find anything out about the heater problem. we have a 1996 4.3 chevy blazer, and it has the same problem. please reply

may be an air pocket in the radiator or block?

Probably the same probleme I had:

When your engine is warmed up doe's both heater hose get equaly hot? I had the same prob when i bought mine , and the hose from the engine to the heater core was somewhat hot but the one going to the radiator was almost cold.After replacing many parts like you did , I found out that the hole on the engine were the hose connect was almost block with residu. Leaving just a small amount of hot water going to the heater core. After cleaning out the hole i had all kind of heat ..... I ve got the 4.3 lt and the hose has a quick disconect to the engine it sit to te back of engine on pass side . Might be a bit different on yours, hope this help.

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91 jimmy 4x4 4 doors

I sure hope you got it fixed by now but if not, spend the money and get a full cooling system flush and refill done by a good mechanic. You probibly have restrictions in the system somewhere and need to clean them out.

Answering a bit late but for those who find this later...

I had exact same problem. I ended up removing both hoses going in/out of heater core (inside engine compartment). Using compressed air, I blew out the core. There was a big 'glob' of stuff in there that prevented water flow. Now, the heater works great!

My a/c and heat don't blow at all, sometimes when i drive it might turn on, but then shuts off after a few mins. Any suggestions or ideas?

might be electrical, or just the a/c clutch goin out.

I had the same problem on my 99 Blazer LT....with electronic A/C

It was a bad solder on the bord in the motor that controlls the blending(airmixing) door for hot/cold air.

I took the motorassembly apart and solder all the connectionpoints and after that it worked again.
But it is very important to have the right position on the turn resistor inside the motor assembly.

Regards,
/Sverker from Sweden

Thank you all for your input on the heater problems. I went looking for the answer to my heater problems on my 2001 blazer and found this site and my husband performed the task of blowing out the heater hoses and it worked. Save us a lot of money. Thank you once again.

the only prob with getting a flush is it could break loose the deposits that have blocked off a hole or a small leak... i got a flush done on a grand am once and it blew the heater core out...

just fyi...

be careful with flushing a neglected system..

I just joined the forum. I'm having the same problem, no hot air blowing. I'm glad I joined as I might can fix this myself. Thanks to all who replied earlier.

I have had that problem with my 97 for me it was a combo, my water pump was going out not putting out enough flow and my heater core was plugged, but do check the upper and lower radiator hoses for cold and hot , lower hose cooler.