Installation Guide

CONNECTION OF 24 VOLT HUMIDIFIER

The integrated control module single humidifier terminal “24

VHUM” is energized with 24 volts whenever the induced draft

blower is energized. Connect the common side of the 24 volt hu-

midifier to the “C” terminal of the thermostat terminal strip on

the control board.

HIGH VOLTAGE !

AVOID

PERSONAL

INJURY

DEATH

DUE

ELECTRICAL

SHOCK

DISCONNECT

ELECTRICAL

POWER

BEFORE

SERVICING

CHANGING

ANY

ELECTRICAL

WIRING

WARNING

24 VAC HUMIDIFIER

The yellow wire connected to the I.D. Blower pressure switch is

powered anytime the pressure switch is closed and provides 24

VAC humidifier control. Remove the yellow wire and connect a

field supplied jumper wire with a “piggyback” terminal to the

pressure switch terminal. Reconnect the yellow wire to the

“piggyback” terminal on the jumper wire and then connect the 24

VAC line of the humidifier to the stripped end of the jumper wire.

Using a wire nut or a field-supplied quick connect terminal can

make this connection. The wiring must conform to all local and

national codes. Connect the COM side of the humidifier to the C

terminal on the low voltage terminal strip (where thermostat wires

are connected) of the furnace control board. DO NOT CONNECT

115V HUMIDIFIER TO THESE TERMINALS.

TWINNING

Furnaces may be twinned without the use of a twinning kit.

Furnaces must be the same model and equipped with

PCBBF145 control boards. Follow the diagram provided in

this manual. Connection of the “twin” terminals of each

control together will allow simultaneous operation of two or

TWINNING C ONNECTION D IAGRAM