Combustion Analysis Log

Record O2, CO2, air-free CO, stack temperature, efficiency and draft at low and high fire.

Test after the furnace reaches steady state (typically 10+ minutes). Use the analyzer manufacturer's procedure and the appliance's acceptable ranges.

Saves on this device as you type. Nothing is sent to us.

Job

CompanyTechnicianDateCustomerAddress

Equipment

Indoor model / serialOutdoor model / serialRefrigerant / gas type

Conditions

Fuel (natural gas / LP)	type
Inlet gas pressure	in. w.c.
Manifold pressure	in. w.c.
Ambient CO before test	ppm
Analyzer zeroed in fresh air; sensor dates OK

Low fire

O2	%
CO2	%
CO (air-free)	ppm
Stack/flue temperature	°F
Draft	in. w.c.
Combustion efficiency (from analyzer)	%

High fire

O2	%
CO2	%
CO (air-free)	ppm
Stack/flue temperature	°F
Draft	in. w.c.
Combustion efficiency (from analyzer)	%

Safety

CO at supply register	ppm
CO in living space	ppm
Spillage test at draft hood (natural draft appliances)
CO alarms present and working
Adjustments made recorded in notes

Notes and recommendations

Technician signatureCustomer signature

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General good practice for field reference. The equipment manufacturer's instructions and local code always come first. Suggest an improvement: hello@hvaccheatsheet.com.

HVAC Cheat Sheet · Free PT charts, code lookups and calculators for techs at hvaccheatsheet.com