Water Heater - burnt wire

[RoadTrip2084]

Hello, so I noticed last fall when I was winterizing my rig that I have a burned up wire going into the bottom of my hot water tank.

The heater was working fine on propane right before this, but I'm wondering if it is part of the electrical heating circuit (the hot water heater can heat using 240v shore power or propane)?

Does anyone know what this wire is for, and if so, what needs to be done to repair it?

[Old-Biscuit]

That Suburban Water heater can heat using 120VAC (1440W electric element) or Propane (12,000btu burner)

That area should have an 120VAC On/Off switch
Looks like someone has removed it and just connected the wires together....which has burnt thru

Electric element is under that oval cover beneath the gas valve
Should be powered by a 15A Circuit Breaker (Black wire??)
From the switch 120VAC would go UP to the 120VAC Set of t-stats (under the 'Push To Reset' cover above gas valve)
Then from the set of t-stats 120VAC power would go down to the electric element
*Left set for 120VAC Element ---- Right set for 12VDC Propane



***Do you have a On/Off Switch inside the RV for the 120VAC Electric Element???

[Brunnie]

You probably need one of these as well.
https://www.amazon.com/dp/B09811QQDF...v_ov_lig_dp_it

[Old-Biscuit]

Originally Posted by Brunnie

You probably need one of these as well.
https://www.amazon.com/dp/B09811QQDF...v_ov_lig_dp_it

Suburban does NOT use the thermal fuse like Atwood
*Thermal fuse is use to stop flame blowback burning up the DC wiring/circuit board that is exposed in the Atwood models
Suburban DC wiring is only one wire to gas valve & circuit board is inside the RV ----not exposed to flame blowback

[RoadTrip2084]

Originally Posted by Old-Biscuit

That Suburban Water heater can heat using 120VAC (1440W electric element) or Propane (12,000btu burner)

That area should have an 120VAC On/Off switch
Looks like someone has removed it and just connected the wires together....which has burnt thru

Electric element is under that oval cover beneath the gas valve
Should be powered by a 15A Circuit Breaker (Black wire??)
From the switch 120VAC would go UP to the 120VAC Set of t-stats (under the 'Push To Reset' cover above gas valve)
Then from the set of t-stats 120VAC power would go down to the electric element
*Left set for 120VAC Element ---- Right set for 12VDC Propane



***Do you have a On/Off Switch inside the RV for the 120VAC Electric Element???

Thanks, this is very useful information. I do have an on/off switch in the kitchen to switch the hot water between electric and propane.

Any ideas on why this wire would burn up like that?

[Old-Biscuit]

Originally Posted by RoadTrip2084

Thanks, this is very useful information. I do have an on/off switch in the kitchen to switch the hot water between electric and propane.

Any ideas on why this wire would burn up like that?

High resistance due to bad connections
*bad connections cause wiring was flopping around, exposed to the elements, spade connector loose, bad crimps

[RoadTrip2084]

Unfortunately, once I've cut away the burned sections there is very little of the original switch wires left to work with. I am unable to get my crimper in there to even add a connector. I'd like to run new wire with adequate length if I could, does anyone have any idea where these two wires actually run behind the panel? Not sure what it would take to gain access since this is sandwiched between the hot water tank and the metal panel.

It seems like one wire should go to the 120v A/C thermostat and the other up inside to the switch on the cabinet in the kitchen. But I need a way to access them to splice in some new wire.

[Skip426]

Can you access the back of the water heater , where the water in/out connections are , the 120 volt wire may have a connection back there .

It's been 6 years since I replaced my Suburban and I really can't remember having any issues with the 120 volt connection . But I think it must have been right there .

As in the posted diagrams , the wiring from the switch runs up to the reset/fuse behind the other removable plastic panel , then back down to the element . You should be able to " fish ' those through.

[Old-Biscuit]

120VAC wiring from Circuit Breaker/Power Panel go to the AC Junction Box on the Right side of the WH Tank (looking/accessed from rear)
*Your inside on/off switch is wired in series with the one that should have been in outside compartment

120VAC Hot wire (Black) then goes to the on/off switch in outside compartment (which is missing and where the wires burnt)

From that switch the 120VAC Hot (black wire) goes up to the set of T-stats (left set) then from set of t-stats down to the AC Element

[esdill]

Originally Posted by Old-Biscuit

High resistance due to bad connections
*bad connections cause wiring was flopping around, exposed to the elements, spade connector loose, bad crimps

It is also possible that the wire was rubbing on that sharp metal edge and cut through the insulation causing it to short to ground. If you are not installing the missing switch when repairing it, make sure to install some type of grommet to protect the new wire from that sharp metal edge.

[RoadTrip2084]

Originally Posted by esdill

It is also possible that the wire was rubbing on that sharp metal edge and cut through the insulation causing it to short to ground. If you are not installing the missing switch when repairing it, make sure to install some type of grommet to protect the new wire from that sharp metal edge.

You make an excellent point. I'd like to re-route the wires such that they don't go anywhere near that hole (keep them on the rear-side of the metal plate). Will take another look today.