HHP PBNU-LD20N140 Installation Instructions Manual - Page 19

Browse online or download pdf Installation Instructions Manual for Furnace HHP PBNU-LD20N140. HHP PBNU-LD20N140 20 pages. Gas-fired furnaces high-efficiency upflow condensing models

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"SC(..,.HtoftC�QIWII"'"'V f (fll
wYC�'NII CX
WHITE-RODGERS
tat
Turn the
rmos
(controller) to
call for heat
Power at transformer
nominal)?
(25 vac
YES
Venter begins
to operate
YES
-
Hot surface
i
igniter beg
n
s
to glow?
YES
Main burner lights?
YES
-
System ru. n s until
call for heat ends?
YES
Call for heat ends
System shuts off?
YES
ends
NOTE: Models with dia:;; n ostic 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
in the external components or wmng. Procee d followmg the troulbleshooting table
below. If 120 vac p ower wiring to furnace is reversed, module will lockout.
50E47 SYSTEM TROUBLESHOOTING TABLE
NOTE: Before troubleshooting, familiarize yourself
with the startup and checkout procedures.
-
Check line voltage power, low voltage transformer
thermostat (controller) . a nd wiring
Place jumper
on
.
1
pressure switch
LP
between "C" & "NC"
Venter Okay?
Check hoses connected to pressure switch
•
Check for k>oseness of pressure tap in burner
•
l
ri
cal connections between pressure
Check e
ct
e
•
s'Nitch and plug connections.
If checks are Okay, replace pressure switch
•
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 cont inuity of flusible link (replace
•
and continuity of tne
!mit
Check for cracks in hot surface igniter (replace if required)
•
Check for 25vac
S
on
•
voltage, replace SOE47.
Check electrical connections between 50E47
•
If Okay, replace gas v
Check continuity of sensor wire and ground wire.
•
po<X
Note: If ground is
occur occasionally even though operation
normal
is
at the .time of check<;>ut.
If checks are Okay, replace 50E47module.
•
Check for proper thermostat (controller) operation.
•
Re
ve MV lead at
SOE4
mo
•
not.
SOE47. If
replace gas valve
Repeat procec_jure until troub lelree
�!
�
ng light also indica
es the problem is most likely
Place jumper
on relay 3R
between "1"
& "3"
?
Venter Okay
YES
1
LP.
box.
1
LP.
switch.
OE4
7 acrosss MV terminals. If no
&
alv
e
.
or erratic, shutdown may
If
7
valve closes, replace
.
-
e
t
n
i
is
op
ra
o
obtained.
venter
it
open)
gas vaJve.