WE HAVE PURCHASED 2 NAT GAS PATIO HEATERS 4 YEARS AGO. WE JUST PURCHASE OUR 3RD HEATER.  WE ALSO HAVE PURCHASED PROPANE HEATERS IN THE PAST. 2 ARE STILL WORKING FINE (ONE HAS A BAD SCREEN AFTER 5 YEARS). WE USE THE HEATERS ON OUR DECK IN COLD WEATHER, LOOKING AT THE OREGON COAST RANGE MOUNTIANS.