I installed one in my Montana 3440RL. It is installed behind my "fake" fireplace and I put the heat register on the front. I have been running it as a back-up to my propane furnace. I run it about 3-4 hours a day. First thing in the morning to take the edge off, then a couple of other times during the day. It has reduced the amount of propane that we use, and it only burns about 4 gallons of diesel a month. Here is a link to the video of the install.