I do not know, it was not the door but the actuator assembly that moves it. It was a warranty issue.

 

I’m still having heater issues. Replaced the heater temperature actuator but it appears that wasn’t it......popped the hood and found my overflow bottle empty, removed the main radiator cap and found the level a bit low.....wondering if I have something else going on and have air pockets somewhere......

 

Or is it a blendoor actuator?

 

Since you are back with a question 10 months an 6 pages later:

Blows cold as in ambient temperature or cold as in A/C?

 

Well life has happened between then and now!!! I live in CA, it hasn’t been cold. It blows lukewarm

 

Temp actuator is the same a blend actuator.

You seem to have narrowed it down to the door moving on it's own?

Replaced the blend door actuator?

Made sure the A/C is NOT running?

If all of that is true that leaves the control panel. Pretty easy to replace and not too expensive, if you get used. We have a couple of member that probably can fix you up with one.

What about the A/C? cold/hot/warm? The way it works is the heat exchanger is always hot, the temp is adjusted by adjusting the amount of ambient air that comes in across the A/C coils. The A/C coils can be either cold or ambient.

https://www.chevyhhr.net/forums/clas...-red-ss-59472/

Hellshotrod is in the inactve ads, but I think he is still selling
https://www.chevyhhr.net/forums/inac...-4-hhrs-55720/

 

The actuator that I replaced was one of the ones you highlighted in the previous pages. It’s the lower one on the heater box that moves when you move the temperature knob.

The A/C is not turned on. The A/C blows cold. The ambient air coming in will be as per that outside temp if I turn it all the way to cold.

When I turn it back to hot, it basically stays at the dead middle (warm). When I look at the position on the actuator, it’s sitting in the center with the control knob in the hottest setting.

 

Time for a coolant change, Dexcool only please and a new AC Delco thermostat 131-158

https://www.carid.com/acdelco/gm-ori...n-131-158.html

It’s a real easy job

https://www.chevyhhr.net/forums/how-...l-p0128-24493/

 

If it just moves on it's own, I can't think of anything besides the control panel. It comes in one piece.

Pull the waterfall off then a couple of screws and electrical connections.

He did that oldblue, a few pages back.

 

Oldblue. Post #22 says he changed the Dexcool and T-stat. Also says later that he did use the AC Delco one.

Now in post #52 it states the coolant is low( overflow bottle empty and under the main cap)

Trying to piece together what he did a year ago and what's happening now.
I would guess he has air trapped in the system from not fully burping it when the coolant was changed.
Blend door problem ? Maybe, maybe not, maybe never was the cause.
He needs to top up the coolant and get the air burped out. Then check from there.