Can Dylux Tankless Water Heater Fit In Cutout Of 16" by 12-1/2" From Old Atwood Heater?

Published 05/27/2026

Question:

My old Atwood has a 16 inch wide by 12-1/2 inch tall opening. Will the black Dylux door cover the old hole?

asked by: Steve

Expert Reply:

Hey Steve! The black door on the Dylux RV Tankless Water Heater # DY54FR measures 16-1/8" wide x 16-1/8" tall, so it can cover a lot of older RV water heater openings, including many that are a little larger than the heater body itself.

The main thing is that the heater body fits a 12-5/8" wide x 12-1/2" tall cutout. If your old opening is 16" wide, the body of the Dylux will be narrower than that opening, so you may need to add framing or blocking inside the cutout so the heater has a solid place to mount. The door helps cover the outside, but the unit still needs to be supported properly behind it.

Steve, if that 16" x 12-1/2" measurement is your rough opening and not just the old door size, this looks workable, but I’d confirm before ordering.

expert reply by: Andrew N