I have a 901 series Duo-Therm that is cracking at the heat exchanger and I was told I need to replace it. What would be

Hi: Thank you for coming to Just Answer with your question. My name is XXXXX XXXXX perhaps I can assist you with this issue.

That is correct........and the best match for a replacement is a Suburban NT series furnace which will just about match the existing holes in the wall of the coach. You have to make a few minor modifications on one, but it will fit fine otherwise. You might be able to come up with a good buy on a used one and save some $$$ if you check on E-Bay Motors or go to Walt's RV Salvage. Depending on the size you have now you probably are looking for a 30K btu furnace, but they come smaller and larger. Please get back to me if you need more help with this. All follow ups are included in our fee.

R.j.

The output.........so you can use a 24K output NT model. Or a 30K would give you more heat quicker.........same size cabinet and hookup. Online you are looking for a Suburban NT-24 or NT-30 and some have an "S" on the suffix. Same thing. Try Walt's or E-Bay and see what comes up. A new one lists for over $450 so use that as a guide. Get back to me if you need more. R.J.

They won't fit the existing holes in the coach. And I haven't found a NT that won't fit into the area of the older DuoTherms. They are a little longer but the width and height are not that much different. What is the measurement of the area where your furnace is?

R.J.