High there, I hope someone can offer some advice as to a repair. My parents replaced a wood/coal burning stove last year, with a Harman Fireluxe Direct Vent Gas Stove.It was plumbed to the existing chimney(chimney is clean).After burning awhile it will all of a sudden pop like there is a gas leak and it all of a sudden ignited,sometimes it is so bad it rattles the glass doors on the stove.They had the company that installed it come out 3 times to repair it but it still has the problem.I don't know what was done to it, but would greatly appreciate any suggestions. I'm a car technician so I know there are a lot of variables to trying to fix something without seeing it in person, but I'm hoping someone has had this problem