Recommended AC System to Replace Two Dometic Duo-Therm AC Units Controlled by the Same Thermostat
Updated 06/03/2026 | Published 05/28/2026
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Question:
I would like to replace two, 2008, Dometic Duo-Therm rooftop AC units w/heat strips that have one Dometic Comfort center controller. I do NOT require the Heat strips on new units. MN on the 2-AC units: 620515.331 What would you recommend? Thanks in advance
asked by: Todd V
Expert Reply:
Hey Todd, thanks for the information! To replace your Dometic 620515.331 13,500 btu Duo-Therm Penguin AC's you'll need to replace the entire system including the air distribution boxes and thermostat. To do this, I recommend the following parts:
Furrion Chill HE RV Air Conditioner System - Multi Zone - 13,500 Btu - R32 item # FR85TD in black or item # FR55TD in white
Furrion Chill HE Replacement RV Roof Air Conditioner Unit - 13,500 Btu - R32 item # FR38TD in black or item # FR26TD
Air Distribution Box for Furrion Chill RV Air Conditioners - R32 item # FR68TD
Multi Zone Controller for Furrion Chill HE RV Air Conditioner Setup - R32 item # FR53TD
There's no way to just replace your AC units and reuse your existing air distribution boxes and thermostat, you'll need to replace all your AC system components. This is due to the EPA changing the regulations on the refrigerant in the AC units at the beginning of 2025. They've been upgraded to R32 and your Dometic Duo-Therm has the now obsolete 410a refrigerant. None of the 410a components are compatible now with the newer systems. You will be able to use the existing wiring to power the AC system and connect the new thermostat if yours has one.
The Furrion parts listed above will provide you with two AC's that can be used in ducted or ductless applications. The multi zone controller item # FR53TD will allow you to use the thermostat included with the Furrion item # FR85TD in black or item # FR55TD in white to control both AC systems.
Are you looking for white or black AC units and do you want to be able to control both your ACs from the same thermostat? I'm just trying to dial in the right system for you. We've got quite a few replacement options and I understand swapping out everything to replace an older AC unit wasn't what you had in mind.
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