Inspecting high-efficiency furnaces

Heating · Condensing Furnaces · printed page 135 (PDF page 136)

Original page Sign in to save

Book index entries

Condensing Gas Furnaces Furnace – Condensing Gas Furnace – Condensing

Text in the illustration

supply plenum
air flow
exhaust vent
heat exchanger
run the furnace long enough to ensure that the spillage switch doesn't activate and turn the furnace off
check the temperature rise and compare it to the recommended rise shown on the data plate (beyond Standards)
check the condensate tubing for dirt or soot on the inside walls
check for leakage or blockage of the condensate tubing
is a neutralizer required in your area? check for clogging
high efficiency gas furnace
make sure that the condensate is discharging to an appropriate location

Generated explanation

A cutaway schematic of a high-efficiency condensing gas furnace shows a burner, heat exchanger assembly, circulating blower, exhaust vent, and condensate drainage tubing. Arrows trace combustion gases through the heat exchanger and upward through the exhaust vent, while circulating air moves upward toward the supply plenum. Thermometers at the lower air inlet and supply plenum illustrate checking temperature rise against the furnace data plate. Annotations direct the inspector to run the furnace long enough to check for spillage-switch shutdown and inspect condensate tubing for dirt, soot, leaks, and blockages. The drawing also calls for checking whether a neutralizer is required, checking for clogging, and verifying an appropriate condensate discharge location; no actual failure is illustrated.

Components

condensing gas furnace burner heat exchanger assembly circulating blower combustion exhaust blower supply plenum exhaust vent spillage switch condensate tubing condensate neutralizer thermometers

Related illustrations

0813

Inspecting high-efficiency furnaces

· p. 135

A cutaway schematic of a high-efficiency condensing gas furnace shows a lower circulating-air blower moving air upward past the heat exchangers into the supply plenum. A burner, serpentine heat exchanger, lower finned ex

0803

High efficiency furnaces have long heat exchangers

· p. 133

The illustration shows a schematic cutaway of a high-efficiency gas furnace with a long, serpentine primary heat exchanger and a secondary heat exchanger below it. Combustion air enters from above at the burner, whose fl

0804

Condensation in high efficiency furnaces

· p. 133

The schematic depicts a high-efficiency condensing gas furnace with a burner, primary and secondary heat exchangers, and a house air blower. Arrows show combustion air entering above the burner and exhaust gases passing

0716.9

High efficiency gas furnace

· p. 113

A cutaway diagram shows a high-efficiency gas furnace with a lower house-air blower and filter, primary and secondary heat exchangers, and an upper warm-air supply duct. Dashed duct outlines and colored arrows indicate c