UHA S
TANDARD
U
NIT
H
EATER
I
NSTALLATION
O
PERATION
AND
S
ERVICE
M
ANUAL
24 of 51
10.5 UHA[X][S] Series Internal Wirin
g
Dia
g
ram
Bl
u
e
Black
Black
O
r
a
n
ge
Yellow
B
r
ow
n
Black
White
White
L2
L1
Black
Black
G
r
ee
n
White
White
G
r
ee
n
G
r
ee
n
Bl
u
e
Black
Black
Black
White
G
r
ee
n
Bl
u
e
G
r
ee
n
24 V
AC
HOT
GROUND
Flame
Black
Black
Black
6
3
4
5
2
1
4
5
3
1
SENSE
ELECTRODE
LIMIT
SWITCH
PRESSURE
SWITCH
AXIAL FAN
GAS VALVE
IGNITION
MODULE
TRANSFORMER
AXIAL FAN (UHA 300,
350, 400) ONLY)
LIMIT
S
WITCH
(UHA
300,350,
400 ONLY)
MANUAL RE
S
ET LIMIT
S
WITCH
(UHA 30 - 125 ONLY)
THERMOSTAT INPUT:
FIELD SUPPLIED
R
= 24 VAC TO THERMO
S
TAT (RED)
G
= MANUAL FAN INPUT FROM THERMO
S
TAT (GREEN)
W
= HEAT DEMAND INPUT FROM THERMO
S
TAT (WHITE)
C
= COMMON
S
IDE OF TRAN
S
FORMER
FLUE
BLOWER
R
G
W
C
ACC
L1
CMB
Blowe
r
Yellow
O
r
a
n
ge
O
r
a
n
ge
O
r
a
n
ge
NOTE:
For field
w
iring into service j
u
nction box, or if any of the original
w
ire s
u
pplied
w
ith the heater
m
u
st be replaced, it m
u
st be replaced
w
ith
w
iring material having a temperat
u
re rating of at least 105° C
(221° F) and 600 volts. For s
u
pply connections
u
se No. 14 AWG or larger
w
ires.