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Randall, RVIA Certification
Category: RV
Satisfied Customers: 10995
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
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I have a new Atwood Model AFMD 35121 self installed that

Customer Question

I have a new Atwood Model AFMD 35121 self installed that replaced a sf30 Suburban in my 96 Forest River camper. I'm having a problem with it staying lit. When I turn the thermostat up calling for heat the fan starts and runs after about 15 seconds the ignitor starts clicking the gas valve opens and combustion occurs after 5-7 second it stops as the fan continues to run, after another 15 secondary it will light again run for 5-7 seconds and then the same thing flame goes out fan still running, will do this 3 times and then fan will run for another 15 second by itself and then shuts down entirely ending the cycle, I've tried it several times with exactly the same outcome.
Submitted: 9 months ago.
Category: RV
Expert:  Randall replied 9 months ago.

Hi! My name is ***** ***** I can assist you with this. I may need some additional information from you first in order to give a complete answer.

Expert:  Randall replied 9 months ago.

It sounds like it is sucking the exhaust gases back into the intake again. Are you sure you got all the parts you needed?

Customer: replied 9 months ago.
I used the exhaust plate and tube that connects over the exhaust tube of the furnace from the outside, I'm not sure how far the plate tube covers the furnace exhaust port maybe 1/2 -3/4 of an inch, .and I had to turn the external plate with attatched tube upside down to be opposite of the furnace exhaust I might add that the suburban exhaust plate and tube also has an air intake opening which is now located above the exhaust exit and also I partially covered that intake opening but not completly
Expert:  Randall replied 9 months ago.

I suspect that is the are sucking in exhaust into the intake and it shuts down. We have that same problem in the shop when bench testing if we don't put the exhaust tube in properly to prevent this.

Expert:  Randall replied 9 months ago.

Just checking back in to see if you were able to resolve this or do you still need some additional input from me here?

Expert:  Randall replied 8 months ago.

Just checking back in to see how this turned out. I am hoping that my answer did prove useful for you. Please let me know and entering in a rating here would be appreciated as that is the only way we get credit from the site for assisting you. And please let your friends know about the service we provide here. If you have more issues "down the road" as they say, please feel free to ask for me by name. Be safe!

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