Install Instructions
18
WHERE TO TEST (CONT.)
Furnaces (continued): Atmospheric, Gas & Oil
Atmospheric Furnace
Draft
Verify proper
• Temperature Rise
• AC side Static Pressure
Drop across coils
Verify proper combustion:
• O2
• CO2
• CO
• Stack Temp
• Efficiency
Natural Gas & Propane
Verify proper combustion:
• O2
• CO2
• CO
• Stack Temp
• Vent Pressure
• Efficiency
Test
• Limit Switch
• Pressure Switch
Set Up
• Gas Pressure
Verify proper:
• Static Duct Pressure
• Temperature Rise
• AC side Static Pressure
Drop across coils
Oil Furnace
Verify proper combustion:
• O2
• CO2
• CO
• Stack Temp
• Stack Draft
• Efficiency
Test & Verify:
• Smoke
Set Up
• Over Fire Draft
Verify proper
• Static Duct Pressure
• Temperature Rise
• AC side Static Pressure
Drop across coils
WHAT RESULTS ARE GENERALLY ACCEPTABLE
Atmospheric Gas
Fixed Burners
Gas Fired Burners Oil Fired burners
(#2 Oil Fuel)
Positive Overfire Gas
& Oil
Oxygen 7 to 9% O2 3 to 6% O2 4 to 7% O2 3 to 9% O2
Stack temperature 325˚ to 500˚F 275˚ to 500˚F 325˚ to 600˚F
Draft (Water Column Inches) -.02 to -0.4 InWC -.02 to -0.4 InWC -.04 to - 0.6 InWC -.02 to -0.4 InWC
Carbon Monoxide (parts per million) <100 ppm <100 ppm <100 ppm <100 ppm
Overfire Draft (Water Column Inches) -.02 InWC -0.2 InWC 0.4 to 0.6 InWC
Smoke 0 (manufacturer's
recommendation)
NOTE: Follow manufacturer guidelines for the specific equipment being serviced
Typical Excess Air Levels
O2% (measured) Excess Air %
Natural Gas 3% 16.7%
LIGHT Oil 5% 31%
Coal 8% 62%