We purchased this unit 10 months ago and really enjoy it. The dealer it was purchased from wasn't very helpful with supporting information. I know we have two 30 gallon LP tanks, but does anyone know which tank is used for what i.e, which one supports the fridge and which one supports the heater etc. Also, I can hear the water pump, but how do you get to it? It appears to be located behind a non-removable wall.


Well-known member
Hi Roxyscout,

Congratulations on the new rig and welcome to the Heartland Owners Forum.

Both of your propane tanks feed into a dual regulator, the output of which supplies propane to everything in the coach. The dual regulators typically are auto-changeover, such that if both tanks are open, the regulator will draw propane from one tank first, and then when that one is empty, it will draw from the other. The downside of this automatic arrangement is that it's possible to use up all the propane in both tanks and find out at 3 AM when it's 15 degrees outside.

Some people only open one tank at a time. That way when the tank is empty, they do a manual changeover - even if it's at 3 AM.

If your 3970RD is a Bighorn, the water pump is near the Universal Docking Center (UDC) where your water hose attaches. The rear wall of the pass through basement storage has to be removed on the UDC side to gain access to the water pump. You can find the screws that are hidden by the felt with the help of a magnet. There are probably also 3 screws that go into the wood panel from the UDC side.