507270-03B
Page 45 of 58
Issue 1904
Figure 68. Integrated Control
(Automatic Hot Surface Ignition System)
Terminal Designations
HUM
Humidifier (120 VAC)
LINE
Input (120 VAC)
XFMR
Transformer (120 VAC)
EAC
Electronic Air Cleaner (120 VAC)
COOL
Blower - Cooling Speed (120 VAC)
HEAT
Blower - Heating Speed (120 VAC)
PARK
Dead terminals to park alternate speed taps
NEUTRALS
Neutral terminals (120 VAC)
Unit Start-Up
FOR YOUR SAFETY READ BEFORE OPERATING
Do not use this furnace if any part has been underwater.
A flood-damaged furnace is extremely dangerous.
Attempts to use the furnace can result in fire or explosion.
Immediately call a qualified service technician to inspect
the furnace and to replace all gas controls, control
system parts, and electrical parts that have been wet or
to replace the furnace, if deemed necessary.
WARNING
Danger of explosion. Can cause injury or
product or property damage. Should the
gas supply fail to shut off or if overheating
occurs, shut off the gas valve to the
furnace before shutting off the electrical
blower deck, before performing any
service procedure.
WARNING
Before attempting to perform any service or
maintenance, turn the electrical power to unit OFF at
disconnect switch.
CAUTION
BEFORE LIGHTING
the unit, smell all around the furnace
area for gas. Be sure to smell next to the floor because
some gas is heavier than air and will settle on the floor.
The gas valve on the unit is equipped with a gas control
switch (lever). Use only your hand to move switch. Never
use tools. If the switch will not move by hand, do not try to
repair it. Force or attempted repair may result in a fire or
explosion.
Placing the Furnace into Operation
This furnace is equipped with an automatic hot surface
ignition system. Do not attempt to manually light burners
on this furnace. Each time the thermostat calls for heat, the
burners will automatically light. The ignitor does not get hot
when there is no call for heat on these units.
Summary of Contents for BG921UH
Page 3: ...507270 03B Page 3 of 58 Issue 1904 Parts Arrangement Figure 1 ...
Page 24: ...507270 03B Page 24 of 58 Issue 1904 Figure 25 Figure 26 ...
Page 38: ...507270 03B Page 38 of 58 Issue 1904 Figure 58 Trap Drain Assembly Using 1 2 PVC or 3 4 PVC ...
Page 44: ...507270 03B Page 44 of 58 Issue 1904 Figure 67 Typical Wiring Diagram ...