Clean and adjust heater deflector fins and element.
Clean fan and lubricate motor.
Clean burner, chamber, thermocouple and control.  (Use a high suction vacuum and/or brush.)
Adjust pilot or electric ignition device.
Inspect vent and damper operation.
Operate unit and adjust burner.
Check operation of safety pilot, gas shut-off valve, and other burner safety devices.
Test the room air around the unit for carbon monoxide emission. Ensure that carbon monoxide level averages less than 9ppm/day (parts per million/day).  If the level of carbon monoxide in the room exceeds 9ppm, turn the unit off and repair.  Retest the unit before it is placed back into service.
Clean surrounding area, record results and findings and report any needed repairs or operational adjustments.

Obtain and review manufacturer's instructions.  Follow manufacturer’s instructions or procedures if different to these instructions or procedures.
Review the Standard Operating Procedure for Controlling Hazardous Energy Sources.
Open and tag electric circuit.

Standard and Phillips head screw drivers-various sizes; Pliers-vise grip (2), slipjoint, needlenose, diagonal; cutting pliers, side cutters; Ball peen hammer; Hack saw and spare blades; 3/8' drive socket set and ratchet; Small set of Allen wrenches; Assorted center punches, drift punches, and steel chisel; 12' measuring tape; Crescent wrenches 4" to 8";  Open and box end wrenches ¼" to ¾"; File; Pipe wrenches to 14"; Small level and square; Pocket knife; Flashlights; Grease guns and oilers; Wire brush; Extension cord and inspection lights; Various cleaning tools - brushes, scrapers, etc; Emery cloth.
Pipe wrenches to 24"; Tubing cutters; Flaring tool; Small acetylene outfit; Packing tool kit and packing; ¾" socket set Crescent wrenches to 14"
Fin comb
Vacuum
C02 analyzer
C0 analyzer
Lubricants. 
Safety goggles.
Gloves.