The Propex heater is designed to be a floor mounted unit. We have spoken with several heater owners that wish to mount the heater in a cabinet or closet above the floor. While this might be convenient for the layout of the vehicle, it poses some potential problems with reliable heater operation. Here's why.

When the heater is mounted on the floor as designed, the combustion piping almost immediately skews away from a vertical orientation. When the heater is mounted in a raised position, the combustion pipes have a longer vertical run and here's where the issue can arise. The hot combustion exhaust tries to rise back up the pipe (hot air always rises) and works against the air flow. This chimney effect decreases the combustion flow velwhich the internal air flow sensor senses as a blockage in the piping. Usually this results in a four-flash error code and locks heater operation.

This can be avoided by floor mounting the heater as designed and running as little vertically oriented combustion piping as possible.

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