SECTION 9: W
IRING
27
9.6 Ladder Wiring Diagram
FLAME
SENSOR
PRESSURE SWITCH
THERMOSTAT
CONNECTION
6
3
4
5
2 1
120 VAC
TRANSFORMER
FLUE BLOWER
AXIAL FAN
AXIAL FAN
UHA (300, 350, 400 O
n
ly)
GAS VALVE
ELECTRODE
IGNITION
MODULE
Flame
S
pa
r
k
Limit
S
witch Limit
S
witch (UHA 300,
350, 400 O
n
ly)
Ma
nu
al Reset Limit
S
witch
(UHA 30 - 125 O
n
ly)
IMPORTANT:
For field wiring into service junction box, or if any of the original wire supplied with the heater
must be replaced, it must be replaced with wiring material having a temperature rating of at least 105° C
(221° F) and 600 volts. For supply connections, use No. 14 AWG or larger wires.