Hello can anyone please help, We have gas logs, the numbers are MERTIX MAXITROL made in Germany, PMAX = 1/2 psi, GV34-B1A0A56, date 0348, 60/3,5 with 068657 listed on the plate below, the proble we are having is the gas logs are leaving soot piles on the fake logs and now there is soot build up and its coming out of the fireplace, its an double side open fire place with vent chimney, I can not verify if this set could possibly be for natural gas only and NOT propane gas tank such as we are on, this is used home purchase and we did not purchase the log set new, can anyone tell us how to verify what type of logs we have? thanks [email protected] Brian