Thor Forums

[Bob Nodine]

As others have said the gauge on the tank is most likely more accurate than the LED indicator inside the coach. I am struggling with a propane/gauge problem now and digging into things have learned that there are two floats inside the tank. One is the overfill protection that will shut off the fill port when the liquid level reaches 80 % of the tank volume. The other is a float that moves a magnet as the liquid propane rises in the tank. That magnet moves the needle on the external tank gauge thru a wall that isolates the tank contents from the gauge so vapor leaks in the gauge are not a concern. The gauge needle is connected to a potentiometer thus changing the resistance of the potentiometer based on the tank liquid level. This is somewhere in the range of 50 to 150 ohms which is a low impedance. That LP level indicator inside the coach monitors the resistance change and gives a very crude indication of the propane available. Any poor connection along the wiring route from the tank to the LED indicator will affect the reading. The mechanism of the tank gauge is also prone to inaccuracy but is a far better indicator than the LED one inside the coach.

I have disconnected the internal LP level indicator and connected it to my Bluetooth SeeLevel tank gauge system that reads in percentage of full. To calibrate this system I need to get the tank full but so far have not been able to get it full. The propane dealers are all over the map on filling the tank. Since owning the RV it has only been filled to capacity twice, when new from the dealer and once by a propane distributor in West Virginia. They are suppose to open the bleed valve and stop filling when liquid propane comes out but most of them are scared and stop way before the tank is full. I thank many of them are confused by the 80% limit and think they should not fill to more than 3/4 of a tank on the gauge. Once in a while you will get a tech that will wait until the internal float stops the fill. I need to find one of those techs so I can get the tank to the FULL mark on the gauge.