Best Replacement For Duo-Therm AC/Heat Unit On 2003 Holliday Rambler

Question

Question:

I have a 2003 holiday rambler endeavor 40ft class A with the duo therm zone 1 and 2 rooftop ac/heat units with 4 button thermostat that I need to replace. Will this manual be a replacement for that?

asked by: Lynn

0

Expert Reply:

Hey Lynn, thanks for reaching out. The Advent # ADV23SR you mentioned comes with a manual control distribution box and does not operate thru a wall thermostat. It also doesn't have any heat capability so while you technically could use it to replace your Duo Therm setup, you'd be losing out on the thermostat control and heat capability.

We do offer the Advent unit with a wall thermostat, and the part number for that system is # ADV92SR. This does not have heat capability, but you can add a heat strip part # ADV34QR. This wouldn't be as effective as a heat pump though.

If you want a system that does both cool, heat and has a wall thermostat, I recommend the following:

- GE Appliances Deluxe Plus RV AC System w/ Heat Pump - Ducted - 15,000 Btu - White - Complete System # GE85ZR

expert reply by: Jesse M

0

Lynn

4/1/2026

If I replaced with one that uses a wall thermostat would I not have to install a 2nd thermostat since the one I have now runs off only one?

Jesse M.

4/2/2026

@Lynn Yes with the parts I mentioned you would be splitting it into 2 zones. You could do a thermostat for one and manual ADB for another. Is your ceiling low enough to where you'd be able to access the manual controls by hand?

Lynn

4/2/2026

@JesseM. Yes it is

Jesse M.

4/2/2026

@Lynn Ok nice so the # ADV23SR with manual control will work for that then you could add the heat strip. Or if you want more heating capacity do the GE # GE85ZR with wall thermostat and heat pump. The heat strips are really only good for taking the chill out of the air on those cold mornings. It would not be a substitute for a heat pump or furnace.

Answer 1

Hi Sherrill! The Advent Air 13.5k RV Air Conditioner #ADV96SR have a decibel rating of 76, so roughly the sound of a fairly loud vacuum cleaner. One thing to also be aware of, this is only the roof top unit and it does not include the other…

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Answer 2

Hey Joy, great question but the difference between the two Advent air AC units you mentioned is that the part #ADV23SR is intended for a non-ducted application and has all of it's controls built into the air distribution box that will be on the…

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Answer 3

Hello Mike, thanks for reaching out. We do have a solution for replacing your Duo-Therm unit, but we do not offer a direct replacement for this. The best option for a replacement will be to replace the entire AC system. The reason for this is new RV…

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Answer 4

Since you have a Dometic Duotherm 630035.321 we do have great options for AC unit replacements that will plug right into the current wiring you have like with the Furrion Chill HE kit part #FR42PV which we have found to be the quietest and coldest…

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Answer 5

Hey Mike! Since it is a supplemental AC and doesn't need to cool the whole thing a 13,500 Btu unit will work well. You can use the Advent Air RV Air Conditioner System #ADV23SR. This comes with a manual air distribution box so you won't have…

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Answer 6

Hey Martin! Carrier is no longer making RV AC units. Although there were some plug and play replacements available in the past, everything has switched to the new R32 refrigerant following 2025 EPA guidelines. This means a complete system replacement…

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Answer 7

Hey Robin! I'm sorry to say that none of the Advent Air AC models are able to replace a Dometic Duo Therm like yours. What I recommend is completely replacing the system. Not only will this allow you to avoid any compatibility issues, it will…

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Answer 8

Hey Wayne! Everything is switching to the new R32 refrigerant which isn't backwards compatible. It also means old R410A parts are disappearing so now is a good time to make the switch. Even if this wasn't the case, we stopped recommending…

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Answer 9

Hey Suzette! We no longer recommend swapping out an AC unit like the Advent Air for Dometic. The issue is most of the time they don't end up being compatible, even if the 6-pin connector matches. Even if you got another Dometic we can't…

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Answer 10

The Dometic model B59516 is showing up as a Brisk II 15K BTU unit so the only thing you'll need to check is what style connector your current unit has. If you remove the cover for the air distribution box inside the trailer you should see the…

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Answer 11

Hey Brian, We have found that RV AC units do not mix and match well with other brands, and we currently do not have a Dometic replacement for your unit. What I recommend is going with a new AC system from Advent, #ADV23SR. This is a similar 13,500…

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Answer 12

Hey Jim, thanks for reaching out! For a completely new AC system we have the Furrion Chill HE RV Air Conditioner System #FR24FJ which uses two AC units that communicate with a single thermostat to give you the feeling like you're at home. These…

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Best Replacement For Duo-Therm AC/Heat Unit On 2003 Holliday Rambler

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