Furrion tankless heating turning on randomly.

[tomlaforest]

So we returned from a desert boondocking trip and I had put the trailer away and turned off all controls and the gas and plugged the trailer in. I was outside the next day and I heard the hot water exhaust fan running. So I verified that the control panel was indeed turned off and also the water pump switch. It only ran for a minute and it turned off. We'll its done that a few more times...that we're aware of anyway! Who's to say how much it's been doing it???
Has anyone else had this experience? I'm completely stumped as to how it's happening.

 

[Hoopy Frood]

I've not had that happen, but it's commonplace for the Battery Disconnect Switch to not disconnect all operations within the trailer. If you want to be sure you have nothing running, install an aftermarket battery disconnect switch, or pull the negative battery cable.

 

[tomlaforest]

I had the battery disconnect, disconnected, along with the solar control. I did have it plugged into shore power but I unplugged that as well this morning when it started to run again. Since the control panel is not turned on for the water heater...it shouldn't be turning on, even if power for it is avaliable. Pretty odd if ya ask me.

 

[Hoopy Frood]

I had the battery disconnect, disconnected, along with the solar control. I did have it plugged into shore power but I unplugged that as well this morning when it started to run again. Since the control panel is not turned on for the water heater...it shouldn't be turning on, even if power for it is avaliable. Pretty odd if ya ask me.

Not really. Like I said: the Battery Disconnect Switch doesn't necessarily shut off all services. Use a clamp-on amp meter and you'll see that there's still a draw on the battery/ies even with the Battery Disconnect Switch in the OFF position.

 

[txloser]

When you say control panel do you mean the one in the trailer or the switch on the water heater.

Was it cold? If the Furion is not turned off at the source and it’s cold it may doing its cold weather protection where it cycles on for a moment. Or trying to at least in this case.

 

[retired_engineer]

When you are plugged into shore power the converter will be feeding the 12V circuit whether the battery is connected or not. It sounds like the master switch on the water heater was not turned off so things like the anti-freeze protection might activate. The master on/off is located behind the outside cover on a panel in the upper left hand corner (on our Furrion at least).

 

[tomlaforest]

When i say control panel i mean the wall switch where you turn it on and off and control the temp settings. I realized that after I turned off the battery connect it was still plugged in. (Operator error) so any way, I'll definitely turn off the master switch that Retired engineer suggested but not until I fish around a little more on it. It's been cold here so it may very well be a protection thing happening, that sounds real logical. If so I want to understand it. It's a new trailer and we're still going thru the learning curve.
Thanks for all the insights.

 

[Prisenhour]

Did you check the switch on the unit itself? I had the same issue until I took the outside cover off and saw the off/on switch on the unit.

 

[297sox]

If "putting away" doesn't include draining water, You need to drain water heater or leave gas/DC on to it, to prevent freezing. Not sure how forgiving piping in them are compared to PEX

 

[huntr70]

If "putting away" doesn't include draining water, You need to drain water heater or leave gas/DC on to it, to prevent freezing. Not sure how forgiving piping in them are compared to PEX

Not at all....small diameter copper tubing is not great for freezing.

 

[tomlaforest]

Did you check the switch on the unit itself? I had the same issue until I took the outside cover off and saw the off/on switch on the unit.

I eventually turned off the master switch so it couldn't cycle anymore.

 

[John Bennett]

I moved our 297RSTS from one storage location to another at the start of this year. When I plugged in the shore power, I heard something running. It was the exhaust fan on the tankless water heater. The rig is winterized, and I verified that the water heater control was off, so I'm not sure what happened. I have stopped by the RV several times and I have not heard it running any more.

 

[tomlaforest]

Morning John. It sounds like you experienced the same scenario as I did. It's still a mystery as to how and why it could turn on by itself, when the control panel is turned off. Well anyways I will just turn off the master switch when it's in storage between camping trips.

 

[Tallscout]

Had a similar scenario earlier this year. As previously noted in the post, a protection means for the water heater during cold temps. I asked the question of a Service Rep at the local dealer. That's what he told me with little hesitation. I eventually found the switch on the unit others noted above. Mine is fully winterized on the water lines, etc. so not worried about it freezing.

 

[retired_engineer]

Morning John. It sounds like you experienced the same scenario as I did. It's still a mystery as to how and why it could turn on by itself, when the control panel is turned off. Well anyways I will just turn off the master switch when it's in storage between camping trips.

The wall control does not turn the water heater off fully. It only disables the water flow sensing and any startup circuitry tied to that process. There is still 12V feeding the main control board in the water heater so the wall on/off control can be sensed and other functions such as the freeze protection will continue to operate.

 

[tomlaforest]

The wall control does not turn the water heater off fully. It only disables the water flow sensing and any startup circuitry tied to that process. There is still 12V feeding the main control board in the water heater so the wall on/off control can be sensed and other functions such as the freeze protection will continue to operate.

Yep, thats sounds right. Our temps were chilly at best here in Arizona when it was trying to cycle on, morning lows in the 40's and it even tried to cycle in the afternoon once...that we caught
So yeah I'll just keep the master off while in storage until i hear in discussions that something is wrong with the circuit board. Till then I won't waste my time on dealership service.