Water Tank Heaters and OneControl

[howson]

Craig Carter - no evidence of overheating or source of the smell noted in post 1?

[Craig Carter]

howson No, not yet other than that portion of the heater that appears to be out. Need to inspect for other electrical items underneath the trailer near the front stairs and look for any chewed wiring.

[Craig Carter]

howson Still moving forward. Purchased two new panels and will replace them tomorrow. It took almost two weeks to get them (in a remote area) and I still need to test them before installing.

Before I cleared the flashing 47 error code from the X4 board, I checked the tank heater output with a meter and it was supplying 4.7V to the panels even though the setting was off in OneControl. Once the board error was cleared, the tank heater output then measured zero volts or 13+ volts based on the OneControl setting. It confirms my suspicion that they were getting voltage even though the OneControl setting had always been off. I just don't know if the board voltage varied during the time that error was present (weeks or months) or if it was consistently supplying a lower voltage? The problem (bad smell) occurred once the temperatures dropped below 45 degrees and the thermostats in the tank heaters activated the pads. We know incorrect voltages can harm other RV electrical items but I'm not sure how sensitive these pads are? I didn't even know that error was present because it's behind the wall.

While I haven't removed the rear underbelly to confirm, it appears the three wires supply the three types of tanks (black/white to one black tank, orange/white to two fresh tanks, and brown/white to two gray tanks). As implemented, you had to use all five or none which is not ideal. Today, I installed an extra switch that allows me to turn on/off by type.



This spot next to the vacuum hose inlet was simply too perfect of a spot; the X4 board is directly behind the stairs. The board power was already pigtailed to the three tank wires so I just plugged the tank wires and board power wires into the switches and added the neutral. These switches now have to be on before any power gets to the tank heaters and they are "visible" reminders of which ones are actually on. They are high enough on the step and below the overhand so I'm not too concerned with anyone kicking them.

The problem has not reoccurred since I cleared the X4 board error but having the extra switches ensures any future error will not cause a similar problem. It would be great if you could set up an alert for any X4 board errors.