Vented Heater Flames Out When Closing Door to Shack

[defiant1]

Looking for some advice.  I have a Williams brand direct vent heater installed in my permanent shack.  On occasion when the door to the shack is closed hard (due to ice build up or shack setting on ice unevenly) to get it to latch, the flame goes out on the heater.  Sometimes I notice it but other times I do not, which is a concern as I don't need propane being pumped into an enclosed area.

Does anyone have any suggestions on how to prevent the flame going out when closing the door?  What is the main reason for this happening?  The change in air pressure from the door slamming shut or the vibration caused by the door slamming shut?

Any thoughts or practical experience would be appreciated.

d1

[bowmandan]

It is pushing air back through the furnace.   Try opening a window a crack and see if it still blows out

[defiant1]

It is pushing air back through the furnace.   Try opening a window a crack and see if it still blows out

Unfortunately, I do not have a window I can open.  I do have a vent in the ceiling above the door.  I wonder if cracking that open a hair would help?

d1

[bowmandan]

Same concept as opening the window.

[defiant1]

Same concept as opening the window.

Yeah, just wasn't sure if the vent being in its current location would have any effect or not.

[bowmandan]

It is like closing your door in your car. With the windows up they shut hard because of air pressure. If you open a window the air has a place to escape and they shut easy.

  In your ice shack with the vent closed, the air pressure will go back through the furnace as the path of least resistance.  With the vent open that should take over as the path of least resistance.

[nocod]

My first thought was lack of oxygen