I held a wrench on the regulator while Lisa tightened the fitting. How to test for a leak in the fitting:
The trailer has two seven-gallon propane bottles. Because of the cold weather, Lisa is using the gas furnace in the trailer a lot, and it's also what runs the stove for cooking. Furthermore, as the electrical part of the refrigerator has stopped working (again) but the propane version is working, that's even more gas being burned. As I mentioned yesterday, normally you want to have both bottles running with a "failover" valve in the regulator that swaps bottles automatically when one is empty. In weather like this you check the valve daily. If it shows red, that means one bottle is empty and you replace it with a full bottle, then move the valve over to the other bottle so that it swaps the other way. In our case, we then roll the empty bottle down to Hanneman's Service and buy seven more gallons of propane. This time of year, we're regulars at their place, and they've been very nice to us, including fixing the tires on our hand cart when they went flat.