One of my Reznor XL200 hanging heater is creating a smell like burnt gas that some people are complaining about. Once and a while I got a small wiff. One heater is cycling on and off about every minute. The fan doesn't have time to shut off. To start the thermostat is put into call the gas valve opens and the burner lights then the fan kicks on after about a minute. Come back to check it later it is still in call but the burner is not lit. I go up to check it and I hear a click and then the burner lights I go back down and look for a flame but don't see one. I go back up and hear a click again and the burner lights. I stay up there this time and the flame goes out again. I start the timer on my watch and in one minute it clicks and lights again. It stays lit for 1 minute 15 seconds and goes out.In one minute it clicks and lights again. All the time this is happening the fan is running. I think this relates to why somet6imes there is a whiff of burnt gas smell.If anyone has suggestions or opinions about this I would like to hear them. Thank you.