Getting a weird smell of hot electrical. This first happened months ago so i stopped using the 120v element. On propane it works great. Finally tested the heating element and it had the same resistance a couple help videos said i should see. Pulled the element and it had white deposits but not too bad. My anode rod can completely fallen off. I had wondered if maybe the rod was interacting with the heating element somehow. I fished the broken anode rod out. Cleaned everything real good. Used a shop vac and piece of hose to suck the remaining white deposits out. Filled the water heater and turned it on. The smell is back and it seems slow to heat. After about 45 mins i turned it back off. Water was just a little bit warmer than how it comes out cold. I have the Suburban paper manual here. Not seeing anything for electrical smell. I bought the tool to remove the heating element. But waiting to buy a new element because the one i have is testing ok. Would be happy if thats the simple fix. Any thoughts on what part is making the smell. I have a fire extinguisher by the front door ready to go. Turned off the breaker to the heater and the switch is off. (side note the switch broke, so i jumpered it, thats when this smell first happened months ago)

Check the on/off button on the water heater body. They burn up all the time.

Slow heating with a normal resistance element means there is resistance somewhere else in series. As mentioned above, a bad switch switch would do that. So would a poor connection anywhere between the power source and element (i.e. thermostat or overprotection device). If you try running it again, search for something hot. Alternatively, ohm out all of the connections with power disconnected.

Remove the cover above gas valve where the 2 sets of t-stats are (Push to Reset Cover)Left side is the 120V AC set of t-statsCheck the black wires/connectionsThe drawn pan is punched out and edges rolled inward...but they are sharp and the wire insulation can get cut up causing burnt insulation and bad connections

Two tests you can run. One is the "SNIFF" test. follow the scent of hot wire and see if you can track it down (not easy) the other is the infra red thermometer test. SHOOT the wires.. all junction boxes. and such. including the breaker that feeds the water heater.. I am guessing a poor connection.

wopachop wrote:(side note the switch broke, so i jumpered it, thats when this smell first happened months ago)I think you answered your own question.Properly replace the broken switch.

Electrical smell from water heater | Good Sam Community

18 Replies

Old-Biscuit
Explorer III
Mar 21, 2019
Thanks for posting update!

Use pair pliers/channel locks and roll those sharp edges in more
With the sections 'flat' the edges are like sharp blades that cut into the wire insulation
And if spade connectors are loose....high resistance/HEAT
wopachop
Explorer
Mar 20, 2019
Old-Biscuit wrote:
Remove the cover above gas valve where the 2 sets of t-stats are (Push to Reset Cover)
Thanks that was it.
Old-Biscuit
Explorer III
Mar 20, 2019
BB_TX wrote:
shastagary wrote:
see page 7 there is no relay on the 120v heating side Suburban Water Heater troubleshooting ..........

If there is an inside switch for the water heater then it is likely that it is a 12 vdc switch that operates a relay on the water heater to send 120 vac to the switch located on the water heater itself. Info below is from the troubleshooting info you provided above. See page 8.

Relay Behind the Switch Panel
Beginning in 2012 or 2013, some trailers may have an interior water heater electric switch that uses 12V DC instead of 110V AC. DC switches are typically rocker switches whereas AC switches are usually wall- type light switches. A 12V DC switch powers a relay that is probably located behind the switch panel. The relay, when energized, supplies 110V AC to the water heater.

Not sure where you got that info?
But that sounds like a Suburban 'DEL' model which is similiar to the Atwood Model that uses a DC Relay

Standard Suburban with electric use the 120V AC ON/Off Switch in outside compartment and RV MFG installs a switch Inside RV ...wired IN SERIES with OEM (both being 120V AC)
BB_TX
Nomad
Mar 20, 2019
shastagary wrote:
see page 7 there is no relay on the 120v heating side Suburban Water Heater troubleshooting ..........

If there is an inside switch for the water heater then it is likely that it is a 12 vdc switch that operates a relay on the water heater to send 120 vac to the switch located on the water heater itself. Info below is from the troubleshooting info you provided above. See page 8.

Relay Behind the Switch Panel
Beginning in 2012 or 2013, some trailers may have an interior water heater electric switch that uses 12V DC instead of 110V AC. DC switches are typically rocker switches whereas AC switches are usually wall- type light switches. A 12V DC switch powers a relay that is probably located behind the switch panel. The relay, when energized, supplies 110V AC to the water heater.
A1RVTraveler
Explorer
Mar 20, 2019
I have found burned wiring caused by loose wire nuts located inside the metal box located on the water heater. This is the metal box where the RV 120VAC wires connect to the actual water heater. The connecter are accessed by removing one sheet metal screw. The metal box is on the top right side of the Suburban water heater when viewed from the back. In most cases, you will have a difficult time accessing the wire nuts without pulling the water heater. This is the place to look if you have a burned wire smell when the water heating is heating water in Electric Mode.
wa8yxm
Explorer III
Mar 19, 2019
To answer your question how muich Power 1500 watts or 12.5 amps unless you do what I did.. trade wattage for re-heat time so I not take 4 times as long to re-heat but do it at 1/4 the wattager (375) and current 3.125) Saves me going out and resetting the park's 30 amp breaker on many occasions.
shastagary
Explorer
Mar 19, 2019
see page 7 there is no relay on the 120v heating side Suburban Water Heater troubleshooting
i have replaced 2 outside switches on mine finally connected the two wires at the outside switch together and added a inside standard house 120v wall switch with pilot light that works much better.
ependydad
Explorer
Mar 19, 2019
Deal with the switch first and follow the issue backwards through the wiring until you find it. A couple of weeks ago, I met a guy at a campground whose water heater's insulation caught fire. He had a slight smell for a little while and even had the 120v element off to the water heater. Smoke damaged a lot of stuff inside the RV. They were just getting it wrapped up.

Myself, I had a wire burn itself up on 120v. We stopped using it and fortunately, it was enough to stop further damage.

Track it down. This can be dangerous.
schlep1967
Nomad
Mar 19, 2019
wopachop wrote:
Thanks everyone. How much power runs through that exterior 120v switch? While researching a month ago i remember someone saying its a relay and does not carry much current. Im just curious.

Another possibility is that the failed switch happened because of a failed relay. The relay could be shorted putting excess current through the switch/jumper.
Again, fix the original problem and the follow-on problems will fix themselves.
wnjj
Explorer II
Mar 19, 2019
wopachop wrote:
Thanks everyone. How much power runs through that exterior 120v switch? While researching a month ago i remember someone saying its a relay and does not carry much current. Im just curious.

The jumper is pretty solid. Its your regular male/female spade connectors. The connectors make good contact and the wires feel crimped nice and tight.

I will poke around and look for loose connections. Thanks for all the advice.

What about a clamping meter on the heating element wires? Would that help diagnose the problem? Actually for fun im gonna check that now. Will test the element and the switch wires.

The clamp on meter will show the same current no matter where you check. The issue is resistance where it shouldn’t be. That extra resistance is creating another “heating element” outside the tank. Overall, the current will be lower than in a working system since more total resistance means less total current. If you’re competent, you can check the voltage at the various connections when powered up. It should be the same everywhere from input to element. If there’s a change from one point to another there is resistance between them.