When running off of 20# tank it works fine on low and medium but, turn it to high and the pilot decreases in size and the burners don't "glow" as much. I have an inline fuel filter (new). When running on (2) 1# bottles it runs perfectly on all settings. The only problem is on high with a 20# tank. Not sure what it is? Any help is much appreciated. Thanks

Heating & Cooling - Mr. Heater - Big Buddy Heater