I have a 2017 Heartland Big Country with a fireplace. When I first turn the fireplace on it produces heat and will run for a while until its cycles out. Once it cycles out at temperature it will not turn the heater back on just the flames are the only thing that's working after it Cycles. Is there a week relay switch the kicks the heater in or a timer that's not working. I've checked everything I can and the manual is not much help.