Why does my propane electric fire walk "boom" when it shuts down? Worried.? ...
Answers: It shouldn't do that it needs to be serviced, cleaned. Mine used to boom when it started because the burner orifice' fundamental the pilot were clogged preventing it from lighting until the gas from the ends reach the pilot, by then in attendance was too much gas for a barely audible start. But I don't know if that would cause that on shutdown.
i would phone to get it serviced it might be something small and cheap to fix but even if its not its still cheaper afterwards to have something drastic develop.