Recommended Replacement RV Air Conditioner For A Dometic Duo-Therm RV Air Conditioner

Updated 05/22/2025 | Published 06/22/2021

Question:

Need a replacement RV AC for a Duo-Therm Model No. 620315.421 15000 btu. Whats the recommended in replacement?

asked by: Frank V

Expert Reply:

Determining replacement of a rooftop condenser unit is really simple. All you'll need to do is remove the cover of your air distribution box to get a look at your system's controller. There will a wire harness that hangs down from the condenser unit and plugs into the controller. On some models they will also mount it inside of the condenser unit (seen in my video below) so if you don't see it in between the air distribution box and condenser then you'll need to get up on the roof and remove the shroud and typically the metal cover over then condenser coils to see it.

If the wire harness has a 6-pin connector then the Advent Air # ACDOM150 will be a direct replacement. If it has a 9-pin connector instead then all you'll need is an adapter # ACCOLKIT to plug into your controller. It's a very simple swap over but you'll want to have a few other people around to help lift the units up and down from the trailer and help you set it in place correctly. If you drag either unit across the roof you run the risk of tearing the roof membrane or gasket on the unit.

If you have any other questions then please let me know.

expert reply by: Kevin C

6 and 9 Pin Connectors
(click to enlarge)

Marino

5/22/2025

Hi i have 3 dometic 620315.421 they use phone type jacks not what you have listed. Need to find new circuit boards for the existing units or purchase new. as they are ducted i do not want to replace wiring unless absolute necessary. Can yo u help

Jon G.

5/22/2025

@Marino For replacement circuit boards or AC units that work directly with your Dometic setup, you'll need to reach out to Dometic directly - https://www.dometic.com/en-us/outdoor/contact-us I can help you out with a new AC unit, but it will need to be a completely new system with a new thermostat like what we see with the Furrion Kit # FR73TD.

Marino

5/22/2025

@JonG What's the cost for 3 units plus the thermostat. Don't want to rewire. Currently phone wire.and phone jacks

Jon G.

5/22/2025

@Marino We don't have any AC units that will be plug and play with your current setup. You'll need to reach out to Dometic about that.