The situation
A customer's Atwood 8535-IV DCLP furnace failed and needs replacing. Theirs is the doorless configuration, meaning no exterior access door is used in the installation. Atwood no longer produces this furnace, so they wanted to know what current unit takes its place.
The short answer
The Dometic DFMD35121 is the closest available replacement.
Why
Dometic acquired Atwood in 2016, so the current Dometic furnace line is the direct successor to the Atwood Hydro Flame units. The DFMD35121 (also listed as 35436 and 35516) matches the 8535-IV on the things that matter most for a swap: 35,000 BTU output, the doorless configuration, same dimensions (20" x 16 1/2" x 7 3/8") comparable duct cutouts, and similar wiring.
What won't necessarily match is the gas line. Expect minor differences in connection location or orientation that need accommodating during install. There is no exact drop-in match for the Atwood DCLP series in all respects.
Before you replace: if the furnace isn't igniting or the blower runs without heat, the failure is often the 31501 igniter control board or the 31098 gas valve rather than the furnace itself. Both are a fraction of the cost of a full unit and worth ruling out first.
What to do
- Confirm your unit is the doorless configuration. If yours uses an exterior access door, you want the doored DFMD35111 instead, or add a 33057 door assembly.
- Measure your existing opening and duct cutouts before ordering.
- Order the DFMD35121. If your RV needs less output, the doorless DFMD30121 covers 30,000 BTU.
- Plan for gas line adaptation. Pick up a 4" duct collar if yours is damaged or doesn't transfer.
Still not sure?
Send us the full model number off your Atwood data plate and the dimensions of your opening, and we'll confirm the fit before you order. Ask us here.