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

Updated 04/02/2026 | Published 04/01/2026

Products Featured in This Question

Advent Air RV Air Conditioner System - Single Zone - 15,000 Btu - White - R32

(212)

$936.64

Advent Air RV Air Conditioner System - Manual - 13,500 Btu - White - R32

(471)

$842.16

Electric Heat Strip for Advent Air RV Air Conditioners - 5,500 BTU - R32

(19)

$98.23

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

(16)

$1446.59

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

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

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.