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Carbon Monoxide Testing of Combustion Appliances

CO leak test performed on all combustion-based appliances. Repair or replace any appliance that fails.

Spec

CO leak test performed on all combustion-based appliances. Repair or replace any appliance that fails.

Applies uniformly from Certified upward.

Scope

All combustion-based appliances in the dwelling — furnace, boiler, water heater, gas range/oven, gas dryer, and gas fireplace.

Requirements

  1. 01.

    Every combustion appliance must be tested for CO emissions at the flue, draft, and ambient air around the unit.

  2. 02.

    Tests must be performed under worst-case conditions: all exhaust fans running, doors closed (negative-pressure stress test).

  3. 03.

    Any reading above the manufacturer's maximum, or any spillage detected, requires immediate service before certification.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Combustion analysis report for each appliance: model, flue CO ppm, draft pressure, and spillage check.

  2. 02.

    List of test conditions (which exhaust fans were running during the worst-case stress test).

Guidance

Why worst-case testing matters

A furnace that vents fine on a calm day can backdraft when the kitchen hood is running. Combustion-zone depressurization is a leading cause of CO incidents in modern tight homes. The worst-case test simulates the conditions where backdrafting will happen first.

Resources

  • BPI 1100/1200 — Combustion Safety Test Standard

    The protocol most home-performance contractors use for combustion safety testing.