Replacement AC For A Coleman Mach III 15k On A 2017 Tiffin Allegro Motorhome  

Question:

Expert Reply:

Hi Jeff!

I know this isn't going to be what you want to hear, but there is not going to be a new direct plug and play replacement for your Coleman Mach III. This is because of the change to the new R32 coolant in 2025 to meet EPA requirements. The old R410a coolant AC units and parts cannot be used with the new systems as they are not backwards compatible. We are in the process of removing all the adapters and systems that say they can be swapped between brands as the AC manufacturers are running into numerous issues with these parts. They will only sell complete systems because it is the only way to know everything will work properly.

With all that said, I recommend going with something like the Advent Air RV Air Conditioner System - Single Zone - 15,000 Btu - White - R32 # ADV92SR. This has the new coolant, includes a new wall mounted thermostat along with the air distribution box, a start capacitor, and works with ducted or ductless set ups. It's also one of our best priced options at the moment as well.

Is your Mach III not cutting it anymore?

expert reply by: Lazer S

0

Lazer S.

9/2/2025

Hi Jeff, Did you decide to try out the Advent Air RV Air Conditioner System as a replacement for your Coleman Mach III? I'm curious to know how it worked out for you, as it could help others facing the same situation.