Outdoor Natural Gas Oven
- Too little air (shutter closed): Results in a rich burn. The flame will be long, yellow or orange, and billowy. It will produce soot and carbon monoxide, and much of its heat potential is lost up the flue.
- Too much air (shutter open): Leads to a lean burn. The flame will be short, loud, and may even lift off or "float" away from the burner ports. This is also inefficient and can be unstable.
- Step 1: Establish a Safe Baseline. Ensure the gas is turned off at the source. Connect your manometer to the test port on the oven's gas valve, typically a small screw-in plug.
- Step 2: Verify Static and Operating Pressure. Turn the gas supply on. The static pressure should be within the acceptable range (usually 5-7" W.C. for natural gas). Now, turn the oven on to its highest setting. The operating pressure should drop but remain stable at or near 3.5" W.C. If it's too low, the problem is in your gas line or house regulator, not the oven.
- Step 3: Calibrate the Air Shutter. Loosen the setscrew on the air shutter. With the oven running, slowly open or close the shutter. Watch the flame change. You are looking for the point where the flame is as blue as possible without becoming noisy or lifting off the burner. This is your optimal mix.
- Step 4: Conduct a Heat Distribution Test. After setting the flame, let the oven preheat for 20 minutes. Use your infrared thermometer to measure the temperature at nine points on the cooking deck (back-left, back-center, back-right, etc.). The temperatures should be within a 50°F variance. If the back is still significantly hotter, a minuscule adjustment to the air shutter (often closing it slightly) can change the flame's shape to distribute heat more evenly.
- Step 5: Document and Secure. Once you're satisfied with the flame and heat distribution, carefully tighten the air shutter's setscrew. I always take a photo of the flame and document the final operating pressure for future reference.