Safety devices for high-efficiency furnaces

Heating · Condensing Furnaces · printed page 134 (PDF page 135)

Book index entries

High Efficiency – Safety Devices High Efficiency Furnace – Safety Devices Safety Devices for High Efficiency Gas Furnaces Condensing Gas Furnaces Furnace – Condensing Gas Furnace – Condensing

Text in the illustration

supply plenum
combustion air
exhaust vent
heat switch
shuts down furnace if flame rolls out of the front of the burner compartment
differential pressure switch
makes sure the induced draft fan is running and that the vent isn't blocked
secondary heat exchanger
house air blower
blower cover interlock
prevents the furnace from running if the blower compartment door is off

Generated explanation

The illustration shows a cutaway schematic of a high-efficiency condensing gas furnace with a burner, serpentine heat exchanger, secondary heat exchanger, induced draft fan, and house air blower. Arrows indicate combustion air entering from above and combustion products passing through the heat exchangers toward the exhaust vent. A heat switch near the burner shuts down the furnace if flame rolls out of the burner compartment. A differential pressure switch checks induced draft operation and whether the vent is blocked. A blower cover interlock prevents operation with the blower compartment door removed, and condensate tubing is depicted below the heat exchanger and vent assembly.

Components

supply plenum combustion air inlet gas burner primary heat exchanger secondary heat exchanger induced draft fan exhaust vent heat switch differential pressure switch house air blower blower cover interlock condensate drain tubing condensate pump