heater not working on a 1992 chevrolet lumina?

Question

no hot air coming from heater, thermostat has been changed.

Answer 1

there's a few things it could be, but first before i would take it apart again did you bleed the system, the lumina, and most cars of to day have a closed system and air has to be bleed out of the system, on the t-stat and on the drives side of the car there are two bleeders, little brass nuts that are 7mm and you may have to do this a few times to get all the air out, do the one on the drivers side first, it will be on the top of the motor on the drivers side on a black steel hose, this is the return hose from the heater core, start the motor up and turn the heater on and on high, and let it bleed tell no more air comes out, then move to the other one on the t-stat and do the same thing, go back and forth a few times to make sure you have all the air out.
if this does not fix the problem again before i would take it apart again look for vaccum hose that is off or broken, if one of those happen the door to the a/c heater will not open or close, if all vaccums are good and in place then take the t-stat out and make sure you have it in right, and not all t-stats say this side in or out, the spring side goes in on the block, if the spring side is showing then it is in wrong.
if none of this helps flush the system.

hope this helps

Answer 2

Are we assuming that the coolant level is good and both of the heater hoses that lead into the heater core are hot at operating temp? I will assume that as there are too many things that could be happening here to cover. If both heater hoses are hot, that means the heater core has good flow through it and there is enough heat inside to blow good heat. This either means you have a problem with the position of the temp. door inside the ducts or you have a plugged air delivery system. The easiest to diagnose is the air delivery system and this is the one that went wrong on this car all the time. The thing I'm assuming again is the actual blower motor is working, but no air comes through the vents whichever one you are using. This was always a plugged AC core. All the air into the car must pass through the AC evaporator core first, before either being channeled to the heater core or out to the vents. This is a major league cost to fix either to replace it or to clean it as most of the dash has to come out. If the blower and air delivery it good, then you will have to check into the temp. door acutator system. Some of these were just a broken vacuum line, usually somewhere in the motor compartment. Some of these use electrics, so you will have to start to diagnose.

Answer 3

Well, you have eliminated one of the likely culprits--the thermostat. Another is the damper under the dash which diverts the air flow through the heater core. On old cars these were lever operated but on anything built in the past 15 to 20 years the switch you turn on the dash to turn on the heat signals a damper to open to channel air through the heater core. If it does not open then the fan just recirculates cool air.

Answer 4

Lumina Slushy Maker

Answer 5

there are several of things to check for.

incorrect installation of thermostat:
did you put in the thermostat in correctly? Thermostats are directional, one side of the thermostat has imprint saying radiator side and the other side will have an imprint engine side. incorrect installation will prevent warm fluid from coming into the heater unit inside the cabin.

heater unit inside is clogged:
a clogged heater unit(small radiator like) will prevent warm radiator fluid from coming inside the cabin to the heater unit to warm up the car.

broken control lever:
the control lever in the car opens and closes the valve to allow warm fluid to come into the cabin which warms up the inside of the car. if that lever is stuck/broken close, no warm fluid is able to come in.

good luck

Answer 6

You may have to take it to a mechanic.