Can Coleman-Mach Signature Mach 15 Replace Front and Middle AC on 2018 Momentum 395M

Updated 04/09/2026 | Published 04/03/2026

Products Featured in This Question

Coleman-Mach Signature Mach 15 RV Air Conditioner System - 15K Btu - Ducted - Textured Black - R32

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$1526.74

Coleman-Mach Signature Mach 15 RV Air Conditioner - 15K Btu - Ducted/Non-Ducted - R32 - AC Unit Only

(5)

$1213.03

Furrion Chill Cube RV AC System w/ Air Distribution Box & Remote - 18K Btu - Ducted - Black - R32

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$1424.95

Furrion Chill Cube Variable Speed RV AC System w/ ADB & Remote - 18K Btu - Ducted - R32

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$1424.95

Question:

hey there i have a 2018 Grand Design Momentum 395m, equipped with 3 AC units. I am looking to replace the front and middle units that are coleman mach 15ks. The rear is a mach 3 i believewhich i plan on moving one of the 15ks to the rear since it isnt cooling. Curious if i would need anything else other than the condenser unit for the roof since i plan on re-using the thermostats. Also the center unit thermostat ties into my propane furnace, that should all be seperate wiring and shouldnt matter on swapping right back to the same make/model?

asked by: Kohlton P

Expert Reply:

Hi Kohlton; the Coleman-Mach Signature Mach 15 # CM89RR is a new R32 AC unit. Everything switched to R32 refrigerant last year due to new EPA regulations. Since these operate at different pressures and temperatures they aren't backwards compatible, so you will have to install a new air distribution box (ADB) and thermostat to go with it.

The part number for the complete system is # CM42RR. The new thermostats will replace the old ones, and the one in the middle will be compatible with your existing furnace. Make sure you hang onto the extra ADBs and thermostats you replace so you have parts for the rear since those have been phased out as well.

Any big trips coming up with the Momentum?

expert reply by: Robin H

Coleman-Mach Signature Mach 15
(click to enlarge)

Kohlton P.

4/8/2026

Alright good to know, so I would need two complete systems that come with new thermostats. The wiring can be re used I assume? Also I have installed the rv air flow foam inserts so hopefully those still are compatible with the air discharge location to my vents? My only other concern is if I have 3 15k units on my trailer if there will Be any electrical overload issues? I know I can only run two when using my onboard Cummins 5500 right now. Just want to make sure when I’m on shore power on a 50 amp it should be able to handle all 3 ac’s. No big trips lined up yet besides beach camping this summer at big lake in Nebraska right on the water!

Robin H.

4/9/2026

@KohltonP as far as I know those inserts will still work since they're sitting up in the duct opening. The 15k AC units are going to pull 12–15 amps each so you're fine on shore power as long as you aren't stacking other heavy loads all at once. You will still be limited on the generator of course. Are you running off of your generator a lot? You could also go with the Chill Cube which has more cooling power, but also greater efficiency and less power draw. You'll get more out of your generator that way. This uses a remote so you could leave the existing wall thermostats alone. The one in the middle will still run the furnace and the one up front can sit disconnected. You can choose from # FR99TD (white) or # FR39TD (black). Enjoy your time at the lake and if you need anything else just let me know!