Need some help here, I have an Atwood gas/electric water heater in my RV. The other day it started giving me fits, it went from starting every time I turned on the switch to intermittent and then no start at all. This was on the gas setting. the main switch is working and I have spark, I can see it and have also pulled it out and cleaned the carbon buildup off of it. The thermal cut off fuse is good, I have replaced both the thermostat and ECO as a precaution. I was initially thinking the problem was in the gas valve and replaced it. The original one and it's replacement are electric solenoid operated and I could not hear/feel the original sending gas through every time. As of putting it back together it sparks once and that's it, no start or secondary restart. Any ideas on what I am missing? And yes I have propane.
It would seem to me, if you've got fire/spark, it would be a fuel issue. Have you cleaned the orifice ( tiny hole) where the fuel is delivered to the chamber for ignition? That's where the problem with mine was.
If you can't fix it with a hammer, it's an electrical problem.
tcb22, You mention that it "only" makes one attempt at a start. How long does it spark, one spark or many, and then stop? Mine only sparks for a limited ( not sure exactly how long) time. If I get a fail to start, I must reset! If you get numerous sparks, I would think that the pilot orifice is plugged. You may be able to clean it with a small, stiff piece of wire!
Good Luck, memtb
It takes 3 things to ignite: fuel, spark, and air. If you have the spark and air, the problem is no gas. I agree that the orifice may be plugged. It should just screw on to the end of the gas line and be easy to remove and clean.
Orifice is clear I pulled it out and checked it when I replaced the gas valve, also no obstructions in the heat/flame tube. I only get one spark per on on the switch and am wondering if it's supposed to have multiple sparks.
Mine sparks continuously until the pilot light is lit. A thermal switch must be involved as once the pilot it lit it stop sparking.