The unit does not work as advertised. The three position BTU gas valve only affords one setting.
I called customer service, as stated in the manual, to seek a resolution to this problem.
I was told by Jason that the unit had only one flame height and that the three position gas valve
regulated three different BTU outputs. As a pipefitter, I have installed hundreds of furnaces, heaters,
boilers and stoves. I assure you, the only way to change the BTU output is to change the amount of
gas supplied, to the unit, for combustion. The same way a stove heats a pot with different heat settings,
BTU input, by changing the flame height to regulate the high, medium and low heat is how the three position
gas valve on this unit is supposed to work. It doe's not. DO NOT BUY THIS UNIT!

Works great use in garage while working in winter. Two car and I operate on low setting I can work in T shirt. High setting will have you in shorts and no top in no time,

Heats room fast. Wish it lighted faster. Next time I'll get a auto lighting heater.

I originally gave a one star rating because the unit only worked for three weeks, after which I called Dyna-Glo and they told me to get a service guy in to look at it--at my expense. That would cost more than the unit. I called again to see if I could get a part for it and they told me they would send a new unit at no charge, which they did. It works perfectly and I guess it all depends on who you talk to when you call, but they stood behind it the second time.

Everything about this heater is satisfactory with the exception of the "manual control" -- a feature not strongly mentioned in the buying process. On the other hand, the price I paid was quite a bit lower than the others, which I presume may be due to their having a thermostatic control. It's well made and puts out a lot of heat, and since my use will be very limited, I'll just tell the occupants of the room it's in to NOT fall asleep after they have activated it (it's in a bedroom at my cabin at 8000 feet in Wyoming.) I did find on one occasion that the electronic igniter would not work and assumed the battery was bad, but later determined that the battery holder was probably at fault, and monkeying around with it got it functioning again. I just wish the fact that it was "manually controlled" had been emphasized -- hence 4, not 5 stars.