I own 5 of the 30,000 BTU heaters, 2 in the propane model.  If I didn't think they were great heaters, I would not own this many. This past winter we had a sustained negative 20 degree below temperature stint that lasted 2 weeks. One of my propane units in my shop was on 24 hours a day through that cold snap, without a hitch. When these units go, if ever, I  will continue to buy them. Great, reliable product.