Water heater won't light

[Butthead]

Fuzion 429 water heater will not light on gas or electric, when I turn it off I hear a click. Any ideas?

[JRTJH]

What brand, size and model of water heater do you have? There's significantly different "technology" between Atwood and Suburban water heaters and the way they work.

[Butthead]

Suburban, SW12DEL, Orfice size 61dms, 12 gallon

[bobbecky]

First, you must make sure you have 12 volts going to the switches that control both the gas and the electric. For gas operation, you must have the gas turned on. For electric, not only must you have the 120 volt breaker going to the water heater turned on, but outside behind the water heater cover in the lower left corner, there will be a little black switch that must be turned on. Once all those switches are turned on, you should be good. Oh, make sure there is water in the water heater tank first.

[ChuckS]

If you have the skill sets then this link starting at page 16 will provide you with troubleshooting steps for both AC and propane mode issue you are having.

I’m suspecting issue with control board relay but follow steps in this service manual link......

http://techsupport.pdxrvwholesale.com/wp-content/uploads/2018/12/Suburban-Water-Heater-Master-Service-and-Training-Manual.pdf

[Daryles]

I have the same model and same problem recently.
Gas hot water heater.
Ok. Turned off electric hot water switch. I read in Suburban troubleshooting manual that Carl posted, http://www.montanaowners.com/forums/downloads.php?do=file&id=17
Water temperature must be below 100 deg before you can do a manual reset. I ran hot water until it ran cold. Went outside and reseated all electrical connectors on the gas valve etc. Tapped on the gas valve (gentle wake up call). Verified propane gas tank level was solid green. Verified gas reset button (above gas valve) was pushed in. Came back inside verified gas worked on cooktop.
Moment of truth. Turned on gas water heater switch. The fault light came on (normal operating procedure per operating instructions. It runs it's own gas line purging, sparking, flame sensor (yes/no) and resetting itself for 15 sec.) I went outside to watch for the flame. By the time I got to it, it was already lit. I put the cover back on and came back in. The fault light was out. I let it heat up the water all the way.
Thanks Carl for the troubleshooting manual and every one for their help.