Arrived at location on 1/16/23 - Once cleaned I examined unit and found gas line to burner ignitor was disconnected. Found loose fitting on valve side. Connected gas line and tightened fitting at valve. Turned on and checked for leaks, none found. Unit last pilot lights and burners fire. Noticed 2 burners not lit at all and 3 more with weak or fluttering flame. Marked burners and shut unit off. Pulled marked burners off and cleaned orifice and burner. Reinstalled burners and tested. All burners now light and have even flame. Okay.