Several years ago we replaced the heater in the new building at the range thinking it had bad controls or a bad gas valve. It turned out to be a defective regulator on the LP-gas tank and we had replaced a perfectly good heater. The heater has been sitting for two winters now and it is time for it to go to a new home.
It is a Mr. Heater Model MHU-50: https://www.mrheater.com/50-000-btu-big-maxx-natural-gas-unit-heater-1336.html. A new one is priced at over $500.
It is a 30,000 BTU propane heater with a blower and it requires a vent. If you have been in the new building when the heater is running, you know it can put out a lot of heat.
If you are interested in buying this heater, contact Marty Didion at: martindidion4@gmail.com and make him an offer he can’t refuse!