FIXED: Water Heater AC Power Issue

[TomMar]

Okay I called the service department and while I am waiting for their call back I figured the forum members could also jump in.

The Suburban water heater (in 120v mode) in my 365 quit working on our last trip. We switched to the 12v/Propane mode and finished the trip without any problems. Trouble shooting it at home
1) I first checked for 120v at the heating element - no joy.
2) I checked the 120v T-Sat/circuit breaker for voltage - no joy.
3) I disconnected the T-Sat and checked continuity it was good.
4) I checked the 120 vac secondary switch in the water heater panel and it was good also.
5) I checked ALL of the 120 circuit breakers in the master CB panel and while none of them are labeled for the water heater, none were "thrown". I reset all of them as a mater of principle.
6) The 120v switch to normally turn the water heater on checked okay. While I did not check the exact voltage I got a differential across it when switched.

I am out of ideas but my main question is where does the 120 vac for the water heater originate.

 

[danemayer]

Re: Landmark - Newport Water Heater Power

Hi Tom,

LM365 Power Control System is set up to shed loads when you're using too much power. The water heater 120V load is the first one that will be shed (power cuts off). If you take the cover off your main circuit breaker panel, I think Relay 1 in the Power Control Section behind the cover interrupts power to the water heater.

Another possibility: You may have a junction box on the front corner of the water heater. There have been a few instances where wires have comes loose inside. Probably a good idea to turn power off before working with that box.

 

[TomMar]

Re: Landmark - Newport Water Heater Power

Hi Tom,

LM365 Power Control System is set up to shed loads when you're using too much power. The water heater 120V load is the first one that will be shed (power cuts off). If you take the cover off your main circuit breaker panel, I think Relay 1 in the Power Control Section behind the cover interrupts power to the water heater.

Another possibility: You may have a junction box on the front corner of the water heater. There have been a few instances where wires have comes loose inside. Probably a good idea to turn power off before working with that box.

Dan - Thanks for the reply. I should have also listed the load sharing was checked and it said the water heater was on I saw the junction box from inside the basement but was delaying taking that step since it I have to disassemble the outside ring to access it. It seems to be the next step but I still wonder is the not a circuit breaker for that component or where is power originate/connection before the j-box

 

[TomMar]

Re: Landmark - Newport Water Heater Power

One more discovery - Circuit breaker 1 I believe is the water heater. I finally made out a "WH" on the label. (Very poor hand writing on list) I pulled the cover off and checked CB 1 and there is 120vac. I guess the next step is to pull the front panel off the water heater to access the j-box.

 

[TomMar]

Re: Landmark - Newport Water Heater Power

Okay the issue has been fixed. I pulled the facing/frame off the front of the water heater, removed 4 screws holding the water heater in place and slid it out enough to reach the j-box. The power wires had been pressed tightly across each other and over the travels the last 1-1/2 years, they wore through the insulation. The wire nut on the one wire and all 4 wires had been hot enough to melt the insulation thus a dead short. Thanks to Dan for suggestions and cross checking my steps. Attached are 2 schematics from the side of the water heater that may help others. One is the 120vac part of the system and the other is the 12vdc part.