LOCATION..................................................................................................................................................................................................................15
General ....................................................................................................................................................................................................................15
Low-Fire Only Installation .....................................................................................................................................................................................17
Furnace Location Relative to CoolingEquipment..................................................................................................................................................17
Hazardous Locations...............................................................................................................................................................................................18
INSTALLATION .........................................................................................................................................................................................................18
Leveling Legs (If Desired) .....................................................................................................................................................................................18
Installation in Upflow and Downflow Applications..............................................................................................................................................18
Installation in Horizontal Applications ..................................................................................................................................................................21
Air Ducts.................................................................................................................................................................................................................21
General Requirements .......................................................................................................................................................................................21
Ductwork Acoustical Treatment .......................................................................................................................................................................21
Supply Air Connections ....................................................................................................................................................................................21
Return Air Connections.....................................................................................................................................................................................22
Filter Arrangement..................................................................................................................................................................................................22
Bottom Closure Panel.............................................................................................................................................................................................23
Gas Piping...............................................................................................................................................................................................................23
Electrical Connections ............................................................................................................................................................................................26
115-V Wiring.....................................................................................................................................................................................................26
24-V Wiring.......................................................................................................................................................................................................27
Accessories ........................................................................................................................................................................................................27
Direct Venting.........................................................................................................................................................................................................30
Removal of Existing Furnaces from Common Vent Systems.........................................................................................................................30
Combustion-Air and Vent Piping .....................................................................................................................................................................32
Concentric Vent and Combustion-Air Termination Kit Installation ...............................................................................................................37
Multiventing and Vent Terminations................................................................................................................................................................41
Condensate Drain....................................................................................................................................................................................................41
General...............................................................................................................................................................................................................41
Application.........................................................................................................................................................................................................41
Condensation Drain Protection .........................................................................................................................................................................43
SEQUENCE OF OPERATION...................................................................................................................................................................................44
Self-Test Mode........................................................................................................................................................................................................44
Heating Mode..........................................................................................................................................................................................................44
Heating Mode-Two Stage.......................................................................................................................................................................................45
Emergency Heat Mode ...........................................................................................................................................................................................45
Cooling Mode .........................................................................................................................................................................................................45
Single-Speed Applications ................................................................................................................................................................................45
Two-Speed Applications ...................................................................................................................................................................................46
Heat Pump Mode....................................................................................................................................................................................................46
Single-Speed Applications ................................................................................................................................................................................46
Two-Speed Applications ...................................................................................................................................................................................47
Continuous Fan Mode ............................................................................................................................................................................................47
Component Test......................................................................................................................................................................................................47
Bypass Humidifier Mode........................................................................................................................................................................................48
Dehumidification Mode..........................................................................................................................................................................................48
Zone Mode..............................................................................................................................................................................................................48
START-UP PROCEDURES........................................................................................................................................................................................48
General ....................................................................................................................................................................................................................48
Select Setup Switch Positions ................................................................................................................................................................................48
Air Conditioning (A/C) Setup Switches...........................................................................................................................................................48
Continuous Fan (CF) Setup Switches.................................................................................................
..............................................................49
Setup Switches (SW).........................................................................................................................................................................................49
Prime Condensate Trap with Water.......................................................................................................................................................................51
Purge Gas Lines......................................................................................................................................................................................................51
Adjustments .............................................................................................................................................................................................................51
Set Gas Input Rate ............................................................................................................................................................................................51
Set Temperature Rise ........................................................................................................................................................................................57
Set Thermostat Heat Anticipator ......................................................................................................................................................................58
Check Safety Controls............................................................................................................................................................................................58
Check Primary Limit Control ...........................................................................................................................................................................58
Check Pressure Switches...................................................................................................................................................................................59
Checklist..................................................................................................................................................................................................................59
—2—