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Topic: Gas water heater fuse blows (Read 398 times) previous topic - next topic

Gas water heater fuse blows

We are working our way east on I40 (headed thru Oklahoma City today) and are having an issue with our LP gas only Atwood water heater on our 1997 U270.  Yesterday, when my wife started the water heater with the switch in the galley apparently it did not start...or not for long as one hour later no hot water for a shower.  Coach was on battery power...no gen or shore power. Found the 2 amp fuse was blown (checked with MMeter) and reseated all connections....had a nice hot shower.  Last night it worked again on battery only.  This am on battery...the fuse was blown again with no red light.  Replaced with last spare 2amp fuse and fired up 8KW gen and this fuse blew as well with a blip of the red and a faint click at or near the circuit board in the hot water bay

Will get a handfull of 2amp fuses today and try again...obviously there is a problem.  Not sure if this is original circuit board but suspect it is and PO never mentioned issues with the hot water hearer.  Also...thought about unpluging the 2 wires to the gas shutoff switch/valve just below the circuit board to see if that is causing too much of a load for the 2amp fuse .... heard this can be the problem and maybe should test before buying a new board.  We will be plugged in for a couple months when we arrive Huntsville AL so perhaps we should install a 110v heater stick so we can have hot showers and not use the LP till we find the problem.
Any help appreciated! 
Carl and Kathleen
Killeen Texas
1997 U270

Re: Gas water heater fuse blows

Reply #1
Carl,

Don't know which model heater you have.  You might find some help/guidance here:

Atwood Water Heater Troubleshooting
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Gas water heater fuse blows

Reply #2
Carl,

Figuring out why the fuse is blowing is first priority, of course, but if you later decide to install a 110V heating element, this thread may be helpful:

Hott Rod Installation, Atwood GH6-7E
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Gas water heater fuse blows

Reply #3
Carl sounds like the control board, if you replace it I would recomend a board from Dinosaur electronics.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

 

Re: Gas water heater fuse blows

Reply #4
I had this problem. It turned out to be the wires going to the thermostat and emergency high water temp shutoff had a tiny nick in the insulation that was touching the exhaust sheet-metal baffle. If a wire touches ground, it is a short and blows the fuse.

When I was troubleshooting my thermostat that rests on the tank disintegrated....and it may have been shorting out....it was like a $10 part and after replacing thermostats no more fuse blowing.

I very much think you likely just have a wire that is somehow touching the metal and shorting out...intermittently. Mine would do it when I closed the bay door.
1998 U270 34'