Atwood Water Heater malfunction...

[AFChap]

I would welcome suggestions on my Atwood water heater. It is a 10gal LP/110v model. We have been using it on electric, and moved to a new location today where we need to run it on LP. I ran it on LP about a month ago and it worked fine, but today when I flip the switch it appears that it tries to light, but fails (I can see the "pilot out" light pulsate as I presume the ignitor is clicking outside). The red "pilot out" light stays illuminated so I am sure it is not a blown thermal fuse like we have had so many of in the past. We did take on 15 gallon of LP this morning on our way out of town, but both the refrigerator and cooktop work on LP tonight so I know the gas is flowing. When the sun is shining tomorrow I'll get in the outside compartment and see what I find ...any guesses on what the problem might be?

[RoadRohrers]

Not sure I have the same exact setup. I often have troubles getting the LP to ignite. It will try three times and quit. I usually just recycle the on/off switch. As always lit on the second series of attempts. Might have someone listen outside to insure the sparker is sparking.

[Ptribbey]

One thing to try, clean the edge connector to the control board. There is also diode that could have opened. If you have an ohm meter, you should have low resistance of the diode in one direction, and high in the other.

[troth]

I'll just add a bit more: Possibly there's still air in the line and it hasn't purged out yet (from the propane refill). Have the wife turn off the switch, then you take one of those long-tipped flame lighters and stick it into the tunnel area by the water heater piezo lighter. Now have her turn on the switch and you fire up your lighter to see if anything's coming thru the gas tube.
If no gas, you gotta go to see if the regulator solenoid is getting power... If regulator solenoid is activating, then you've got one of those notorious little spider webs in the burner tube or orifice blocking the gas. If the solenoid is not opening to allow gas through, then it could be a bad brain (try cleaning the wire contacts with a pencil eraser). -Some brains had little blade fuses (3 or 5 amp, easily visible) that you could check. Try jumping out (bypassing) the thermal fuse once too.

[traveler of california]

When mine did that, I needed a new circuit board.

Nick, Journey '01

[tomsm]

One other possibility - there is a flame detector that determines if the burner actually lit. Without confirmation from that detector, the brain will shut down the LP flow. If it lights, but then shuts down, check the position of that sensor and make sure it's in the flame. If it is, you probably need to R&R the sensor.

[RoadRohrers]

computer acting weird. Sorry, nothing further to add.

[AFChap]

Thanks for the comments. I got it to light. When I opened up the WH I found the thermal cut-off was wet inside the clear sleeve around it. I recall it getting wet when I opened the pressure valve above it when I flushed the WH out ...I presumed it would dry out ...bad assumption. When I removed the thermal cut-off to dry it out I noted the connection terminals were a bit corroded. I cleaned them up, then had the DW flip the switch inside while I listened and watched outside (why don't they have a switch outside?). It lit up as normal.

[KIX]

Paul, I have found that a product called Boeshield T-9 is excellent for protecting against corrosion. It lasts way longer than WD40. Apply it after clean up. Available at auto parts stores......at least in the SouthEast
Still have those shades/visors......in the box