Startup· Moderate 45–60 min
Post-install verification of a residential 80% or 90%+ furnace.
Tools
Combustion analyzer · Manometer · Multimeter
1
Verify gas pressure
Static 5–7" WC NG (11–14" LP). Manifold to nameplate — typically 3.5" NG / 10" LP.
2
Clock the meter
Confirm firing rate matches nameplate BTU input.
3
Check combustion
CO stack <100 ppm air-free; O2 6–9%. Adjust airflow or gas as needed.
4
Measure temperature rise
Return-to-supply rise within nameplate window (typically 35–65°F).
5
Static pressure
Total ESP ≤0.5" WC; adjust blower tap or duct.