My heater is not working why?

Hello,

This sounds like you have a temperature blend door actuator that is out and needs to be replaced, Here is a guide to help you get the job done.

https://www.2carpros.com/articles/replace-blend-door-motor

Here is where the actuator is on your car.

Check out the diagrams (Below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

Yes I can feel the air blowing from the vents and the speed matches the blower setting. I just replaced the thermostat this evening but it is still blowing cold air.

Well, if the engine temp is normal and good circulation through the heater core, I'd have to check the heater control valve, where applicable, and the blend doors.

Thank you I checked the temperature blend door actuator and had it replaced by my neighbor not he heater works! yA! I love this site.

My 2001 Blazer heater will not heat. Engine warms up. Fan works, but only cold air. There were no symptoms -- just started.

There are a few possibilities;

The thermostat is stuck open. If you have a temperature gauge you can eleimanate that one.
The heater core valve is stuck or the cable that actuates it is not working. Check for the heater hoses near middle of firewall. One will have a ball valve on it. someitmes the clamp that holds it in place comes loose or it gets stuck. See if you can move it by hand, only when engione cool, and do so gently. Check under the dash and make sure that the cable from the heater control thatr actuates the temperature is connected and seated properly. Check other cables, especially the heater box door cable, to make sure they are connected and seated in clips.

Temp guage shows the engine gets up to temp. Neither heater hose has ball valve. Cables seem ok.

The heater control is actually electric. I am providing you with the wiring diagram. Follow the left most fuse at the top and it will go down to the heater control temperature solenoid wchich has location on it. I believe it is on heater box. So, check the fuse, then the wires and ground for tight corrosion free fits and grounds should contact clean metal. Then I would suspect the control solenoid.
Before replacing it go get the trouble codes pulled. You can get this done for free at any Adavance Auto or Auto Zone.

heater in 2001 chevy blazer is not working correctly? Blower works but air does not get warm.

Does the vehicle reach normal operating temp? Are the heater hoses hot?

Also check for hvac codes. Below is schematic, problem with air-temp actuator/door, is possibility?

It's currently in the low 40s. I start my car to defrost it for 10 minutes. I come back out and the windows are not defrosted. I switch to the fan with the heat on and I get cold air. Same thing when I switch it to the AC. What are some possible causes for this issue and what would I be looking at in cost for repair (Unless it's something any person can fix)? Thanks.

There are a few possible causes. Check coolant to ensure it is at the correct level. Also make sure that the coolant is getting warm after engine has been running. Check hoses for leaks/loose fits. If all is good then your car might need a new thermostat or heater core. The first few things you should be able to do yourself. If none of those work and you conclude you need a new heater core or thermostat, the prices for parts are rather low but the labor costs are high due to the difficulty of installation.

[quote:de7275daf8="toreygolden"]Heater problem
2001 Chevy Blazer 6 cyl All Wheel Drive Automatic 99100 miles

It's currently in the low 40s. I start my car to defrost it for 10 minutes. I come back out and the windows are not defrosted. I switch to the fan with the heat on and I get cold air. Same thing when I switch it to the AC. What are some possible causes for this issue and what would I be looking at in cost for repair (Unless it's something any person can fix)? Thanks.[/quote:de7275daf8]

Awesome. I'll check that. Thanks!!!

The heater in my chevy is not working. I have changed the thermostat, the coolant level is full. I believe the heater core is fine. I think it may be air mix mode door may be stuck and not shutting all the way. Where can I located? and is this possible?

Hi:
I will assume the engine is running at a normal operating temp., and the blower motor is working. To check the function of the doors, you will need to craw under the dash, identify the HVAC duct work, and remove it to get into the doors. Before doing that, however, with the engine at normal operating temp and the heater on, make sure both heater hoses are getting hot.

Let me know what you find.

Joe

Hello,

Having problems with getting heat to blow out of the vents.

When I turn the heat on, I only get cool air.

When the blower motor is turned on, it sends air to where I direct it via the knob. Defrost, leg, etc...

The A/C works properly.

A little more in depth,

- The lines that run off the heater core from the firewall do not get hot at all. The line that should feed coolant into the heater core (off the intake manifold) does not even begin to get warm, needless to say the return line back to the water pump is cool as well.

- The truck is not overheating. It also does not take a real long time for the truck to get up to temp. I don't think it's the themostat.

- I do not smell coolant in the cab of the vehicle.

- I flushed the heater core only a few months ago, with pressure (water nozzle). I was actually surpised that I did not get a lot of nasty gunk coming out like you hear a lot of folks talk about.

- I replaced the thermostat less than 2 months ago.

- The intake manifold was replaced a little before I did the thermostat.

- Coolant levels are full in radiator and overflow tank.

- Upper radiator hose get plenty hot.

I plan on grabbing a new rad cap and reflushing the heater core, just as a "hey, this is the easy stuff to eliminate first" kind of thing.

Will probably take the inlet heater core hose completely off (from firewall and intake) and see if thats clogged.

- This was an intermittant problem when it really first began. I could not get heat to come out the vents on the way to work in the morning but on my way home I was then getting heat.

- Could it possibly be the water pump?

- I have read through a haynes manual (not very useful for this topic) the only thing I did find was a mention of a way to test the water pump was to just basically see if those 2 lines were warm.

If the heater core hoses are not getting hot neither the inlet of out let, there has to be a blockage. If the waterpump was bad, the engine temp would be a problem. Make sure the hoses aren't plugged, remove the hoses make sure where they attach to the engine aren't plugged.

my blazer has no heat have changed thermostat2 times flushed everything changed antifreeze heat in hose going to heater core very little heat in hose coming out fuses are fine what's my problem?

the heater core is plugged. you can either replace the heater core, or you can perform a super flush on it. the super flush is a product made by prestone. it works very well if you follow the directions. it take a couple of hours to do, but it works

i have no heat,. it blows normal no leaking anywhere i put a new thermstat in but still nothing. could it be a fuse?

when vehicle is hot feel the heater core hoses and get back to me with what you find. let me know their temperatures. of both of them. be specific.

This guide will help fix it

https://www.2carpros.com/articles/car-heater-not-working

Please run down this guide and report back.

Not blowing hot

That's way too much information to digest, so you might want to start by checking the coolant level. Feel the upper radiator hose and the two heater hoses. They should be too hot to hold onto for very long.

my blazer has no heat. we have replaced the thermostat, flushed the heater core and recently replaced the intake manifold gasket.the blowers are working fine, could this be a problem with the vacum lines, if so, where are those located??

see if your blend door is working ok first. you may have a vaccum line disconnect by the engine. if not try to back flush the heater core and make sure it is not plugged. I know you said you did flush it, but did you back flush it. some times you have to do a super flush on the heater core to clean it out. prestone makes a flushing kit that works great for this

I have auto temp control and cant get any hot heat,only luke warm .anti freeze is clean and the temp of the blazer is about 180.Could it be my temp dial and if so is it expensive?

Ok on your truck it uses a blended heater system. Meaning that is uses a door to direct air through the heater core. The more through the core the warmer the air and the less through the core the cooler the air. So what needs to be checked is the operation of this door. Is there anything that fell down the vents that could be blocking the door? Now here is a pic of the heater blend door actuator and it should only take about an hour to replace.

Could you explane where vthis is located.Is it visable by just looking under the hood and if so does it look exactly like the pic or could it look a little different?
Thanks

It is inside the truck on the passenger side on the heater box behind the glove box. I am not sure exactly were but here is a pic of the heater box part that is behind the glove box. Hope this helps if not get back to me and I will see if I can find better pics ok.

Not throwing no heat husband flushed radiator didn't work change and put new thermostat in it and new radiator and fresh antifreeze and still no heat what else could it be beside heater core also having trouble if we push it to make it up a hill and we take it slow it goes but if he push it to make a steep hill it wants to die before we reach the top he cleaned out the mass floe thing and change air filter but still wants to die runs good any other time only on hills what could that be is it time to junk it

It sounds like you got a couple different problems? As far as performance issues, how long since a tune-up? Are there any applicable trouble codes? To check codes, yourself, at the least, you need an obd2 code reader. Some of the national brand auto stores will check codes for free, if there are any.

If the heater isn't blowing warm air, fell of heater hoses, both should be hot. Could be heater core issue, also, check temp door under the dash.

When going up steep hill, will the tranny downshift to lower gear? If you downshift does it do better going up the hill?