Odd Breaker Tripping Issue

[PhxCapeCodder]

In my 2005 Forest River 5th Wheel, with 30 amp service, the main 30 amp breaker slot shares a spot with a 15 amp breaker.  The 15 amp breaker immediately trips while connected to shore power and also when not connected to shore power and just running off 2 12v batteries.  When I reset the tripped 15amp breaker, it trips the main 30 amp breaker immediately however if I leave the 15 amp breaker tripped and reset the 30 amp main breaker, the 30 amp main breaker remains untripped.  The problematic 15 amp breaker is marked water heater, however, even with that 15 amp breaker tripped the propane heater lights and works fine.  Despite the 15 amp breaker being tripped, I can't find anything that does not work.

Performing searches here, I have not been able to find anyone with a similar problem.

Should I replace the dual 30amp/15amp breaker?
Can anyone recommend any specific troubleshooting steps I can try?

Thank you and Happy Thanksgiving.

 

[Gary RV_Wizard]

Those circuit breakers should have nothing to do with battery operation unless you are using an inverter to supply 120v power.  The breaker for the water heater has nothing to do with propane operation either - the only time the heater needs 120v is when running in electric mode.

Replacing a breaker simply because it trips is mostly wishful thinking. It is conceivable that a breaker fails for no good reason, but nowhere near as common as internet  savants would have you believe. The best explanation is that there is indeed a short on that 15A circuit, so you need to figure what is powered by it and fix the problem. It might be the electric heat element in the water heater, but it might be something else too. RV builders are rarely complete or accurate when they label breakers.

 

[Rene T]

Welcome to the forum
Tell us the name and model number of the water heater.

 

[Prior member]

If your water heater is dual, (both gas or electric), the 15 amp is probably for the electric and there is a short in it some place.
Why not disconnect the wire from the 15 amp breaker and see if everything works normal.
If it does and you never use the electric, just leave it disconnected.
If it is from the water heater and you want to use it on electric, you'll need to trouble shoot it and see where the short is

jack L

 

[grashley]

If your water heater is dual, (both gas or electric), the 15 amp is probably for the electric and there is a short in it some place.
Why not disconnect the wire from the 15 amp breaker and see if everything works normal.
If it does and you never use the electric, just leave it disconnected.
If it is from the water heater and you want to use it on electric, you'll need to trouble shoot it and see where the short is

jack L

You just saved me some typing!  My thoughts too.

 

[alan6051964]

is it posb no water in hot water tank ?, and its tripping breaker because of this ?. double check to make sure water is in the hot water heater tank ?. chances are, your heating elements are bad ?, thermostat bad ?. this runs off 120 volts on the electric side.

 

[cavie]

The 30 amp side of the breaker is the MAIN breaker for the camper. The 15 is for the WH. Sounds like you have burned out/shorted the heater element. Leave the 15 amp off and see if you have hot water when using electric not gas. The 15 cannot trip when you're on Batteries.

 

[PhxCapeCodder]

Thank you for your rapid responses and great tips.  ;D  This 5th Wheel is new to me as is this forum.  We are planning to try out part-time RV living in this, our first 5th wheel.  It's an incredible upgrade from our previous Lance Truck Camper.  Regardless ...

The water heater is a Suburban SW6CE. 
The water heater works perfectly using propane, therefore I am fairly certain there is no problem with that heating element and I know there is water in the tank.  I have disconnected the 15a side of the breaker and have not found anything adversely effected (not working).  After hours of tracing wires, I have not been able to track down the short or exact issue related to the tripping 15a breaker., therefore I will assume it is the electric heating element as you mentioned. With the shore power disconnected, water heater turned off, it does trip the breaker (odd) as I would think that on battery power, the breakers would not be impacted as you mentioned.

I was unaware the water heater was dual purpose and have always relied solely on propane. For now I will leave the 15a side of the breaker disconnected and continue to rely upon propane for my hot water needs.  Perhaps, after some research, I will opt to replace the entire thing one day with an on-demand model.

Happy Holidays to all and again ... thank you.

 

[grashley]

Many HWH are dual power.  Mine can run on gas (when shore power is not available) or on electric, which is "free" with the camp site.  If I want hot water FAST or need fast recovery time, I can run both heaters.

My FW has a breaker dedicated to electric HWH element.

Disconnect the wires from the heating element and measure resistance (ohms) across the element.  It will let you know if it is the problem.  They are inexpensive, available at big box stores and the local hardware store and very simple to replace.

 

[Gary RV_Wizard]

You can test the electric heat element with an ohmmeter - a shorted element will read about zero and a broken (open) element will be infinite resistance.

Get a Suburban SW heater service manual at http://bryantrv.com/docs2/docs/subsw.pdf