Setting gas manifold pressure

What is going on

You set manifold pressure after you have confirmed that supply pressure is within limits. Do not adjust the regulator on a bad supply, or you will chase your tail. I always read supply first with a calibrated manometer, then work on the manifold for both high fire and low fire. The regulator only has so much range, and when the flow needs a big change, the right answer is a different orifice, not cranking the screw. Gas work is for a licensed gas technician.

Likely causes

• Supply pressure outside the limits for adjustment
• Manifold pressure out of spec for the fuel type
• Regulator out of range for a large flow change
• Weak or lazy flame after conversion or altitude change

Check in this order

1. Use a calibrated manometer to read the gas supply pressure
2. Confirm supply is within limits maximum 10.5 in w.c. natural gas or 13.0 in w.c. LP, minimum 5 in w.c. natural gas or 11 in w.c. LP for adjustment
3. Set manifold pressure to the high-fire and low-fire values for the gas type
4. To adjust, remove the regulator cap; turn the screw clockwise to raise pressure or counterclockwise to lower it
5. Replace the regulator cap securely
6. Keep final manifold pressure within 0.3 in w.c. of the specified value
7. For large flow changes, change the burner orifice size instead of the regulator
8. Leak-check any disturbed fittings with an approved detector

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