Fix for no cabin heat on 2012 Vauxhall Ampera / Chevy Volt

Cabin heat faults are relatively common on the Vauxhall Ampera and Chevy Volt.
From 2012, GM fitted an inline filter to the heating system. Unfortunately, the filter isn't documented anywhere and it can become blocked with debris. Many owners have spent a lot of money chasing this fault. The dealer is often no help, because the filter isn't documented anywhere.
If your Ampera or Volt doesn't have cabin heat in either EV mode or engine mode, then this may be the solution.
Fortunately, you don't need any expensive parts for this fix - just a few hours of your time and some skinned knuckles. Be warned, this is a horrible job...

[@crafter-grafter007]

Thank you sir! Just completed the nasty job, and hot air is indeed coming through 😊

[@Jkellogg22]

Before you disassemble, Use a marker and make marks on both hoses and the filter housing. This will make reinstallation much easier.

[@Askalon9]

My service manual has no reference to that filter. Thanks for documenting its removal. I just change out the CHCM for similar symptoms.

[@realtalk4eva646]

Wow. Good job and Thank you. My spidey sense is going off on this one so here is where I start...

[@simonrogers7841]

Great video. How do you even see the hose connection to the heater matrix? I can just about get to the 2 way valve....

[@FEAdeES]

Thank you for this reference video, it was very helpful for me. But I seem to have air in the lines since when I start heat in the cabin, I hear gurgling sound which indicates air. Did you have that problem? How did you resolve or what do you recommend? Thanks again

[@paulpschierer-barnfather6060]

I didn't have any problem with air getting in; I guess I was lucky. I tried to minimise the risk with the hose clamps.

[@bdbdthatsallfolks]

Any pointers on the quick release? I dont want to break anything.

[@starwishes]

Hello, we’ve have the filter cleaned once, and replaced once and the heat is gone again. Both times at the 10 days mark!
By chance have you done anything else to get the heat running?
Thanks in advance

[@paulpschierer-barnfather6060]

Was the filter blocked the second time? If so, I can only suggest a complete cooling system flush to get rid of any debris. The filter seems to block really easily...

[@jordanstreet7253]

Does it not need bleeding for air?

[@paulpschierer-barnfather6060]

I didn't need to bleed mine, but I guess I was lucky. I was careful not to let any air in using the hose clamps.