Pre-Delivery/Install Checklist

whl-648 Rev. 001 Rel. 000 Date 4.11.19
57
Table 32 - Diagnostics and Suggested Corrective Actions
Display Condition Diagnostic Possible Corrective Actions
Nothing appears on
the display control
panel and no other
boiler components are
operating
Control is not
receiving 120V
power
Ensure service switch and/or circuit
breaker to boiler is turned ON
Turn on service switch or circuit breaker to
power boiler
Is there 120V at the service switch
Troubleshoot and correct the power supply to
the manual switch
Is the ON/OFF switch inside the boiler
cabinet is turned on
Turn ON the manual power switch inside the
boiler cabinet
Check for 120V at the line voltage terminal
block located inside the boiler cabinet
Correct wiring inside the boiler cabinet using
the wiring diagram in the installation manual
Inspect the fuse. Replace as necessary
Replace the fuse with the proper part found in
the replacement part section of this manual. If
fuse blows again, recheck the wiring per dia-
gram
Nothing appears on
the display control
panel, but the boiler is
operating
Occurs when
communication
is lost from the
control to the
display
Check for loose connections and proper
pin alignment / engagement on the
control’s plug
Check for continuity on the wire harness from
the display to the control. See repair parts sec-
tion for proper replacement part.
Cycle power o and on using boiler power
switch and check for operation
Replace with new display module. See repair
parts section for proper replacement part.
Display repeatedly goes
through initialization
sequence
Occurs when
control does not
receive signal
from fan
Cycle power o and on using boiler power
switch and check for operation
Replace fan
CH Return Temperature Sensor (7855P-097)
Exhaust Temperature Sensor (7850P-070)
Storage Tank Temperature Sensor (7855P-057)
CH Supply Temperature Sensor (7855P-030)
DHW Temperature Sensor (7855P-094)
Outdoor Temperature Sensor
(7855P-084)
Temperature (
o
F) Resistance (Ω) Temperature (
o
F) Resistance (Ω) Temperature (
o
F) Resistance (Ω)
-4 62162 -4 28409 -4 99200
5 48440 5 22152 5 74229
14 38045 14 17408 14 56090
23 30107 23 13782 23 42790
32 23998 32 10990 32 32930
41 19261 41 8824 41 25550
50 15562 50 7131 50 19990
59 12655 59 5800 59 15760
68 10353 68 4747 68 12510
77 8520 77 3906 77 10000
86 7051 86 3233 86 8050
95 5867 95 2690 95 6520
104 4908 104 2250 104 5310
113 4125 113 1891 113 4350
122 3485 122 1598 122 3590
131 2957 131 1356
140 2520 140 1155
149 2157 149 989
158 1854 158 850
167 1600 167 733
176 1386 176 635
185 1205 185 552
194 1051 194 482
203 920 203 421
212 808 212 370
Table 33 - Temperature Sensor Resistance