Atwood heater problem

Most likely a defective thermocouple.
Find the model number of the heater then google "Replace thermocouple in Atwood xxxxxxxx water heater" Replace xxxxxxxx with your model number.

Just checked now (from the other post) and that model doesn't have a thermocouple. It has a spark and sense electrode which is more than likely the problem

Double post deleted.

Post which year/model you have/

Stupid question. Is there water in the heater? Forgetting to cycle water into the water heater has been my brain dead happenning in the past. I usually drain all systems after use when a non use period follows an outing. An empty heater will reach high temp in a very short time making the sensor think the water is hot enough so as to stop the burner.

Gee waited a whole minute before reposting.

Check the thermal cutoff fuse connection. I don't know how to post a picture, but if you open the hatch and your looking at the thermostats it's the one labeled T STAT. Disconnect it then disconnect the fuse (the clear tube) from the wire and clean the wire connector. Mine had some corrosion on it. I cleaned it up and added some dielectric grease to the connection to the wire only. Fires up like new now.

I assume you are running on GAS..

On mine, when new, and cold, it took me several tries before it would work, Kept going to FAULT. I am assuming moisture was keeping the flame sensor (Thermocouple) from sensing. Eventually I had to replace the control board and that fixed it..

Spark gap adjustments are often off, and this can prevent ignition.

Those are my two best guesses.

IF it is lighting (you will see and hear) 3 times and then going FAULT. the control board or thermocouple are the culprits. DInosaur boards are superior to Atwood OEM.

Actually it is rarely the control board that goes on Atwood heaters. The connections to the board seem to be the issue. I have cleaned the electrical connections several times and finally solved the issue by using a small office type binder clamp to keep the connections tight. Eventually I also had to replace the ignitor.

All Thanks for your input and suggestions. This was a double post and i was responding to the other post.

Below is what I posted on the other post.

Thanks for the Help, Had to replace the electrode. Brought the control board down to my local RV supply store and they did check it out and found that it was working properly. The electrode did look good, gave it a quick cleaning with some fine emery cloth porcelain was still shinny with no cracks in it. guess looks can be deceiving. As soon as I installed the new one and made a few adjustments it fired right up.