Community Forums

hayward3411 · 05-30-2018, 03:13 PM

The 120v stopped working last Sunday, gas ok. It looks like the electric heating element is on the backside, this means that I need to pull it out to replace the element. What a pain.

I noticed that the EMS light is not showing power to hot water heater, so I kept pushing the select button hot water heater was selected. It shows 33. when off.

Pictures attached:

Gen set/50 amp power when I took pictures.

Any ideas or opinions?

BFlinn181 · 05-30-2018, 05:32 PM

Before pulling the tank out, I'd verify that the element has burned out. It could be a tripped breaker, bad over-temp thermostat, bad wire, etc. If you can access the wires on the element, you could test the ohm rating for that particular element.

Old-Biscuit · 05-30-2018, 05:37 PM

Your 2008 Atwood Combo Water Heater uses 12V DC to trigger the 120V AC to the electric element

Water heater has an individual 120V AC Circuit Breaker....check that it is NOT tripped

Water heater uses SAME set of t-stat/ECO as propane side

120V AC comes from the AC Circuit Breaker to the DC Relay and then to the element
DC Relay and element are on backside of water heater ....protective cover over them
*12V DC has to be present on YELLOW wire for DC Relay to function
*AC HOT (Black) wires DO burn off the DC Relay
*Element burnt out/shorted

redcolorado · 05-30-2018, 07:32 PM

I have had 3 issues with my 10 gal Atwood water heater.
First was a relay on the EMS board failed. This resulted in no 120 vac to the water heater relay at the back of the water heater. I bypassed the relay on the EMS board and the issue was resolved.
Second issue was a burned out water heater element. This was caused by me leaving the electric water heater switch on when I drained the tank. I replaced the element and issue resolved.
Third issue was the relay on the back of the water heater burned and I do mean burned up. Replaced the relay and issue resolved.
These issues occurred over a 8 year period.
My coach has a door under the water heater near the back that is opened by removing 2 screws. Changing the relay at the back of the water heater and the element are not difficult.

hayward3411 · 05-31-2018, 02:15 AM

Great ideas, 120v fuse is OK, will check 12v fuse.

T-stat works on gas so I assume that's OK.

I will pull up the floor in closet to see if I can access the back of water heater.

Need to clean radiator anyway.

hayward3411 · 05-31-2018, 02:33 AM

I might get lucky here, after watching some youtube videos it shows that a 33. on display means that my average was over the 30 amp I was plugged into. The EMS reduced the available power, it looks like it has shedded the water heater.

There was some talk about a 3 hour average power consumption, coach is sleeping in the barn now all unpacked from last weekend. It's plugged into 30 amp power.

I will look at it later after my dentist appointment, maybe see if I can reset it.

hayward3411 · 05-31-2018, 03:42 PM

I will update after I have access to a 50 amp plug.

If no 12v I would not have any power, all works except water heater.

BFlinn181 · 05-31-2018, 05:10 PM

If you have an electrical management system, when it only sees you're connected to 30 amps it will shed electrical loads that could exceed 30 amps. If you're connected to 30a, then the WH should work on electricity if you aren't also using air conditioners. See if the WH works on electric if no other big electrical consumers are on.

hayward3411 · 06-01-2018, 12:40 AM

Thanks for the info Bob,

I have had this coach for 9 years now and can't ever remember the EMS shedding before anything has turned on.

All power works except water heater (EMS light off) when plugged into 30amp.

I was plugged into a 30amp box last weekend when after 3 days the shedding light remained off for the water heater.

I ran the genset for about 1/2 hour and the hot water heater light remained off.