Hot Water Tank Problem

[Pete Hanson]

We were camping this weekend and running the hot water tank on propane. We noticed that the water seemed to be getting exceptionally hot and when we ran hot water there would be lots of air in the lines for the first few seconds. My thought was that the thernmostat was not working properly and we were making steam.

On the second night we all of a sudden heard what can best be described as the sound of a garbage disposal turning on and all the 110v circuits went dead. The breaker that tripped was not in the Monty or on the pedestal outside. It turned out to be the breaker in the breaker box that serviced our site and the rest of the row we were in. Only our site breaker tripped though. I reset the breaker and the same noise occured and the breaker tripped again. Since the noise was coming from under the cabinets where the heater is located I shut off the water heater circuit breaker in the Monty and all the 110v circuits ran fine from that point on. Keep in mind, I didn't have the electric anode turned on at any time.

The heater ran on the propane but continued to create very hot water and air. Has anyone experienced this? Do you think it could simply be the thermostat/over temp component failing and tripping the breaker? I will call for service tomorrow. I may be looking at a new water heater.

Pete

[noneck]

Now that is interesting...if running on LP then there is no 120v circuit involved, it uses the 12vdc to manage ignition.

Have you checked to make sure the AC switch is turned off?
> Little black switch located behind the outside access panel.

Have you checked to see if the over-pressure valve is activating?
> Same location behind the outside access panel...be very careful it will release hot water.

Does it run very long time and never turn off?
> This as you suggest would boil the water...maybe use meat thermometer to see how hot your water is?

**When arriving at new location, do you purge the water lines by operating both cold & hot in kitchen and bath before turning on hot water? If not then this could be the source...if not then you have something like the over-pressure valve dumping water and allowing air to enter the system...or the park has a lot of air in the water?

[Pete Hanson]

Have you checked to make sure the AC switch is turned off?
> Little black switch located behind the outside access panel.
Yes....I checked the on/off switch several times

Have you checked to see if the over-pressure valve is activating?
> Same location behind the outside access panel...be very careful it will release hot water.
The high pressure valve has never released

Does it run very long time and never turn off?
> This as you suggest would boil the water...maybe use meat thermometer to see how hot your water is?
Not sure on this one

**When arriving at new location, do you purge the water lines by operating both cold & hot in kitchen and bath before turning on hot water? If not then this could be the source...if not then you have something like the over-pressure valve dumping water and allowing air to enter the system...or the park has a lot of air in the water?
Yes....it is part of our routine to purge any air that might be trapped in the lines when we set up. The interesting thing is that if I let the hot water tank cool a bit we don't get the air in the lines and the cold water side never had air in it.

The only thing I can figure is that the thermostat / high temp cut off circuit must be short circuiting or something like that. There may be an internal water leak but we see no evidence of water leaking out of the tank. I will be calling our mobile service tech tomorrow to set up an appointment but I may pull the unit out myself out of curiosity. :-)

[FLSTS03]

Hey Pete, Do you use a bypass valve to control the hot water output that may have been turned off during the winter? It's my understanding that these heaters have no adjustable t'stat and can run very hot(normal) and that some rv owners use bypass valves to reintroduce cold water to basicly mix down the output. Also, the t'stat could have come loose during travel which could cause the t'stat to read improper. Good luck Steve

[capn chris]

Pete,
Sorry to hear of your dilemma. Look forward to hearing what you find out.

[Tom S.]

quote:Originally posted by FLSTS03

Hey Pete, Do you use a bypass valve to control the hot water output that may have been turned off during the winter? It's my understanding that these heaters have no adjustable t'stat and can run very hot(normal) and that some rv owners use bypass valves to reintroduce cold water to basicly mix down the output. Also, the t'stat could have come loose during travel which could cause the t'stat to read improper. Good luck Steve

Can you explain how that would work? Don't the bypass valves cut the water heater completely out of the water system? With them on, no water goes into the water heater (and thus none comes out) and with them off, water flows through the heater normally... I think.

I wish we did have a thermostat - our heater runs on the cool side.

[noneck]

Yeah...as Capn Chris said...let us know what you find this one has me stumped.

[Pete Hanson]

I talked with my mobile RV technician on the phone today and after describing to him what we experienced he suggested that there must have been a problem with the power setup at the campground. Knowing that my electrical setup at home here is correct he has me trying the heater at home to see what happens. I have had it on for about 4 hours now and the heater seems to be working quite normally.

He told me that reverse polarity or even voltage on the ground peg can make a water heater do some strange things even when other 120v aplliances work with no problem. This was all he could come up with over the phone and it will be a good test. He was baffled by my description of the sound it made just prior to the circuit breaker popping though. Anyway, I am going to leave it on as though we were camping and see what happens. Here is another reason to make sure we check the pedestal circuit prior to plugging Monty in.