DIY Heater Valve Cleaning

[7thDimension]

So it seems that a lot of people are having cabin heat issues. I had no heat on either side, but sometimes I would get a little heat on the passenger side. I fixed it by cleaning the heater control valve. The assembly consists of the aux water pump, and the two heater valves. It controls the heat for both sides of the car...

Here is how to clean it:

It is not necessary to drain the coolant, you will lose about 30oz when you remove the hcv...

This is what it looks like:


Where it is:

Loosen clamps and disconnect hoses and plugs. Pull straight up to remove.


Loosen the screws, and pull solenoids from the assembly.
What to clean:



Put it all back together and bleed.


How to bleed the cooling system after you're done:

Start the engine and wait for it to reach operating temperature. Once the car is warm, raise the front end of the car, we want the front to be higher than the rear, as if you were parked on a hill facing upward. You can jack the front up, drive onto a curb, or park on an incline. With the front end raised, and with the engine still running, turn the heater to 90º and the fan on low for both sides, and open the hood.


Loosen the bleed screw just enough for coolant and air bubbles to start running out. Keep the bleed screw open until there are no more air bubbles, and just coolant is running out.

Test heater for proper operation, and you're done. Enjoy.

[IcemanBHE]

Good job. Did you test the solenoids with power to see them work?

[7thDimension]

Good job. Did you test the solenoids with power to see them work?

I plugged them in to the car and could see them actuate when I adjusted the temperature... I don't have any pics though.

[IcemanBHE]

Did you do the same before you worked on it?

Just curious.

[M I C H A E L]

nice work, how long did it take to get the HVC out

[7thDimension]

Did you do the same before you worked on it?

Just curious.

Yes, the solenoids wouldn't move at all before, and they got hot to the touch, they were all rusted. After I cleaned the plungers, I had to use a bunch of WD-40 and fumble with the heater controls to get them to move at all. Now, about 1k miles later, they still work fine.

nice work, how long did it take to get the HVC out

It took about 15 minutes just to remove it from the car.

[IcemanBHE]

Cool. I have an extra setup. Ive been going to play with this...

Somewhere you can get new rubbers for these..but I cant find that now.

[sigtwenty]

Good to know.....I have a spare and no heat in my extra 7. So this may be a cheap way to get hest working again

[purplecty]

cool. I have an extra setup. Ive been going to play with this...

Somewhere you can get new rubbers for these..but i cant find that now.

etk?

[7thDimension]

...So this may be a cheap way to get hest working again

It's actually free...

[David325e]

Very, very appreciated OP. I've been having intermittent failure of the driver's heat. Most of what I found was about having heat while the AC was on. And the heat related fixes were about replacing wiring for a total failure. Gunked up passages seems much more likely for my issue.

I know what I'm doing next week now.

[M I C H A E L]

thats an easy fix. i have to replace the whole unit on mine.

[7thDimension]

Very, very appreciated OP. I've been having intermittent failure of the driver's heat. Most of what I found was about having heat while the AC was on. And the heat related fixes were about replacing wiring for a total failure. Gunked up passages seems much more likely for my issue.

I know what I'm doing next week now.

Glad I could contribute... Hope it works for you, I used a can of brake cleaner and a blow gun to clean out the passages. Intermittent heat on one side most likely means you're wiring is fine. Just make sure to work the plungers up and down by hand and use some penetrating oil to relieve the solenoids of any stickyness.

thats an easy fix. i have to replace the whole unit on mine.

Why? Mine was pretty far gone, I had to use a hammer to get one of the the solenoids to move, it was corroded badly. But now, it works perfectly... Just spend some time cleaning it before you replace it, they're not cheap...

[M I C H A E L]

mine is causing piping hot heat from the floorvents and upper dash vents. idk it that will fix it.

[7thDimension]

mine is causing piping hot heat from the floorvents and upper dash vents. idk it that will fix it.

I think it might. You're solenoids are sticking open, or not getting any power. If they're not getting power, a new hcv won't fix your issue. Normally, the solenoids are powered when the heater is off, and the solenoids are not powered when the heater is on. They close when they receive power... Check for 12v at the hcv plug with the climate control set to 60° and the key in position two. If you have voltage, clean the hcv, if you don't have voltage, than your problem is elsewhere.

[M I C H A E L]

thanks for your help bro, alls i gotta do is check that out, then program it so when i turn the car on the a/c orheat dont come on automatically. thats really annoying...

[7thDimension]

thanks for your help bro, alls i gotta do is check that out, then program it so when i turn the car on the a/c orheat dont come on automatically. thats really annoying...

No problem... Yeah, that's the only thing that annoys me about the digital hvac controls. If I turn off the hvac, next time I start the car it turns on automatically, I don't know what genius implemented that feature. Although most cars with digital hvac controls do that, it doesn't really make any sense.

[M I C H A E L]

No problem... Yeah, that's the only thing that annoys me about the digital hvac controls. If I turn off the hvac, next time I start the car it turns on automatically, I don't know what genius implemented that feature. Although most cars with digital hvac controls do that, it doesn't really make any sense.

yeah ikr? i didnt think it was that easy to take that thing out. finally i should have some more a/c coming from my footwell and upper dash

[IcemanBHE]

etk?

Keep dreaming.

[purplecty]

Keep dreaming.

[TheLadiesMan]

Great job!

[7thDimension]

Great job!

Thanks...

[RIboater]

another option to elimintate the HVC as a problem completely is to replace it with a brass "T". I ran that way most of the winter last year until I found my problem was a missing fuse. Not blown fuse. Missing fuse. Long story about an indy I will never go back to.

[Hueristic]

another option to elimintate the HVC as a problem completely is to replace it with a brass "T". I ran that way most of the winter last year until I found my problem was a missing fuse. Not blown fuse. Missing fuse. Long story about an indy I will never go back to.

Throwing the "T" in will also allow the use of the vehicle while working on the solenoids.

Also guys If you do this continuity check the coils and if there is an open you can solder the wire. Corrosion can eat through them.

[shotheway1]

Will the T allow operation of the ac