I bought two thinking I would get the advertised 110 hour running time on each thinking maybe it would make a difference if the tanks were filled at a different place but it still ran out around 70 to 78 hours. The tanks are 20 lb. tanks. The low setting claims to be 7,000 BTUs on this size tank. How come after using four tanks I still only get 70 to 78 hours per tank? What's wrong with these heaters? Is this a case of false advertising to sell a product? I also own a Big Buddy portable propane heater. It advertises its low setting at 4,000 BTUs and will run 120 hours on low using a 20 lb. tank and I am always in the ball park when I use that one. The reason I bought the Dyna Glo was the advertised 7,000 BTU setting on a 20 lb. tank and an advertised running time of 110 hours. I didn't think I could go wrong with nearly twice the BTUs using the same 20 lb. tank.

Heating & Cooling - Dyna-Glo - Double Tag-a-long Heater