i-N2
"SC(..,.HtoftC�QIWII"'"'Vf(fll
wYC�'NIICX
NOTE:
Models with dia:;;nostic light have sslf-diagnostk; capabilities.
If
the light on the
module is on continously, the fault is likely to
be
internal to the module. To make
sure, interrupt the line or
25
voir thermostat power for a few seconds and then
restore power. If internal fault is indicated again, and flame sensor is not shorted
to ground, replace control.
A
flas
�!
ng light also indica
�
es the problem is most likely
in the external components or wmng. Proceed followmg the troulbleshooting table
below. If 120 vac power wiring to furnace is reversed, module will lockout.
WHITE-RODGERS
50E47 SYSTEM TROUBLESHOOTING TABLE
Turn
the
rmos
tat
(controller) to
call for heat
Power
at transformer
(25 vac
nominal)?
YES
Venter b
e
gin
s
to
operate
YES
-
Hot surface
igniter
b
eg
i
n
s
to glow?
YES
Main burner lights?
YES
-
System ru.ns until
call for heat ends?
YES
Call for heat
ends
System
shuts
off?
YES
ends
NOTE: Before troubleshooting,
familiarize yourself
with
the
startup and checkout
procedures.
-
Check line voltage power, low voltage transformer
thermostat (controller) .and wiring
Place
jumper
on .
Place jumper
pressure switch
1
LP
on relay 3R
between
"C" & "NC"
between "1"
& "3"
venter
Venter
Venter
O
ka
y
?
YES
•
Check hoses connected to pressure s
wi
tc
h
1
LP.
•
Check for
k>oseness
of pressure tap in
burner
box.
•
Check e
l
e
c
t
ri
cal connections
between pressure
s'Nitch and plug connections.
•
If
checks are
Okay,
replace pressure switch
1
LP.
•
Check that pressure switches 2LP, 3LP& 4LP are
closed.
If
no
check
for loose hoses or loose pressure tap on burner box.
•
If checks are Okay, replace pressure switch
2LP,
3LP or 4LP.
•
Check
electrical continuity of flusible link (replace
it
open)
and continuity of tne
!mit
switch.
•
Check for cracks in hot
surface
igniter (replace if req
u
ire
d
)
•
Check for
25vac
on
S
OE4
7
acrosss
M
V
terminals. If no
voltage, replace SOE47.
•
Check electrical connections between
50E47
&
gas
vaJve.
If Okay, r
e
plac
e
ga
s
v
alv
e
.
•
Check continuity of sensor wire and ground wire.
Note:
If ground is
po<X
o
r
erratic, shutdown may
occur occasionally
even
though operation
is
normal
at
the
.time of check<;>ut.
•
If checks are Okay,
replace 50E47module.
•
Check for
proper
thermostat (controller) operation.
•
Re
mo
ve
MV lead at
SOE4
7
.
If
valve
closes, replace
SOE47. If
not.
replace gas valve
-
Repeat procec_jure until troublelree
op
e
ra
t
i
o
n
is
obtained.
