What AC Unit can Replace My Dometic Duo Therm with Model number 600315.321?

Updated 05/15/2025 | Published 04/19/2025

Question:

Hi. It looks as though the Advent units ACM150 and ACDOM135B would work in my motorhome, and Kevins video actually indicates that is true. However, there is a statement in the descriptions of both units that they are not compatible with any Dometic Duo Therm RV AC systems. Seems sort of contradictory. Let me give you my information and let me know what units, if any, would work in my system. First of all, both air conditioners are controlled by one thermostat Zone 1 and Zone 2. This is a 99 Monaco Diplomat with Duo Therm units. Model number is 600315.321. The unit Im replacing does have the 6 pin connector. The power box looks to be right under the unit, but I dont think it is part of the A/C. I will have to double check that. Thanks for any information. I will continue to research this in the meantime.

asked by: Chuck W

Expert Reply:

Hello Chuck,

Great question, and if you could let me know what page the Kevin video is on, I would love to take a look to see exactly what you are referencing. There has been a lot of mixed information in the past about what units the Advents can actually replace.

So here’s what’s going on: even though the Advent units (like the # ACM150 and # ACM135 ) are physically a good fit and might look like plug-and-play replacements for your Dometic Duo-Therm setup, the tricky part is actually in the control system. These Advent units aren’t compatible with your current Dometic thermostat system, especially since you're running a dual-zone setup with that 6-pin connector, which tells me you're using the older Dometic Comfort Control Center (CCC). That’s where the confusion comes in. When Advent says "not compatible with Dometic systems," they mean it won’t work with the Dometic thermostats or control boards, not necessarily the rooftop unit itself.

In your case, since your 1999 Monaco Diplomat has two units controlled by one thermostat (Zone 1 and Zone 2), the easiest and most seamless route would be to stick with the Penguin II. This will allow you to keep your current thermostat and wiring setup, which is a big win. For 15K BTU # DMC98ZR for with heat pump, # DMC88ZR without heat pump.

Now, if you really wanted to switch to an Advent, you'd have to replace both rooftop units and the thermostat, and possibly even rewire parts of the system. You’d also lose the convenience of your dual-zone setup unless you added new zone controls, so it’s definitely a bigger project.

If you do want to go with the Advent set-up please let me know if you have a ducted on ductless system and what

expert reply by: Kate F

Chuck W.

5/1/2025

Hey Kate and thanks for your reply. The link to Kevin's video is https://www.etrailer.com/tv-review-advent-air-rv-air-conditioner-ACM150B.aspx. I appreciate the information you have given me. Originally, my system was probably controlled by 2 individual thermostats. We bought the motorhome from my RV mechanic and he more than likely rewired the system into one thermostat that controls the furnace as well as the air conditioners. So, if you are fairly certain that the Penguin II will work in our motorhome, we will probably go with that one in the near future. Our system is ducted and it looks as though the Penguin will work in that set-up. Just let me know if you think of anything else related to this installation of which I should be aware. Our plug is a 6 pin standard connection. Thanks again!

Kate F.

5/12/2025

@ChuckW Sounds like you are not in a huge hurry Chuck. I am going to reach out to Dometic with your specific model number just to confirm, I will let you know as soon as I hear back. If you have any questions in the meantime, please ask away =)

Kate F.

5/14/2025

@ChuckW I was able to confirm with Dometic that the # DMC86ZR is the correct replacement unit for your setup. They also mentioned that if the current controls are still in good condition, they can be transferred from the old unit to the new one. At the moment, the Penguin unit is not available for purchase. There is a shipping issue, Dometic isn’t packaging them well enough, and too many are arriving damaged. Unfortunately, I don’t have a timeline for when this will be resolved. That said, I do have an alternative option for you: the Furrion Chill Cube RV Air Conditioner with Air Distribution Box – Ducted – 18,000 BTU – White # FR99TD. This would be a completely new setup, but the good news is it’s significantly more efficient and will cool your space much faster. It also comes with a remote thermostat, so there’s no need to install a new wall thermostat, just mount the included bracket. I’ve attached two videos for you to check out. Let me know what you think, and again, I’m very sorry that the Penguin isn’t available right now.

Helpful Links

tv-mdemo-vendor-lippert-rv-ac-fr99td.aspx

tv-review-furrion-chill-cube-rv-air-conditioner-fr39td.aspx

Chuck W.

5/14/2025

Kate, thank you very much for your time and information. I will certainly consider your recommendations. I did watch the videos also. Fortunately, at the moment, I have been able to get the current unit started again and it seems to be working ok for now, but it is anyone's guess as to how long that will last. Thank you again for all your help. Chuck W