Low flames

The problem may be in your regulator. About five years ago the feds required all grill regulators to have safety features which now often cause the problem you are having.

Make sure your regulator is right side up for starters Then check the venturri tubes to be sure some spider hasnt nested in there. Make sure it is clear.

Here is some additioinal info u may need to read:

Fuel Hose and Regulator: The output of a propane tank is much greater than you need for grilling so the regulator controls the amount of fuel that can flow to your grill. The regulator attaches to the tank by a flexible hose with an O-ring to create an airtight seal. Regulators are preset by the manufacturer and should not be adjusted by you. If you look at your regulator you will notice a small vent hole in the center. Common problems here are clogged vent holes, which can cause irregular fuel flow and can lead to trouble. Usually you can clear it by tapping or blowing into the vent. Other problems are fuel leakage caused by a worn or damaged hose or O-ring. To determine if there is leaking mix dish soap and water in equal parts and coat everything from the tank to the venturi tubes. The tank needs to be connected and on but the control valves off. If you find a leak replace that part. Control Valves: The controls do just that, control the flow of fuel to the burner. Some grills have one control valve and others have several. The valve consists of several components that are specifically designed on a number of factors. You cannot repair a bad control valve and if need be you should replace the whole unit. Before you do, however remove the control valve from your grill and inspect it. Like other parts of your grill, insects love to climb in here and make their homes. At the heart of this is the orifice. The orifice controls the flow of fuel and can become clogged. If it is use a thin wire to clean out. Make sure you put it all back together the way you found it. Without the orifice you cannot control the amount of gas flowing to the burner and run the risk of explosion. Venturi Tubes: The venturi tubes connect the control valve to the burner(s) and mix the fuel with air to provide flame. To mix the air into the fuel there is an open gap in the fuel line here that can easily become obstructed. Insects, especially spiders, love this space and given half a chance will move in as quickly as possible. The best solution for this is to wrap the venturi tubes with an aluminum screen that will not block the airflow but will keep the critters out. Another common problem here is a misalignment of the venturi tubes with the burner. Typically the venturi tubes are simply placed in the fuel line and can get knocked out of place. The venturi tubes typically have adjustable shutters. You may need to adjust these to regulate fuel flow.