I have 2 propane tanks on my TT and have no idea how full the tanks are. They can be removed and weighed but would like to be able to glance at it and know. I have read that the after market gauges...
Do you have an automatic changeover regulator? If so the regulator indicator will show red when one bottle is empty. There is a lever or pointer that will be pointing to the empty tank. When you see red... move the lever to point at the other tank and get the empty tank filled. Repeat indefinitely. Check daily if running the furnace moderate to heavy.