Troubleshooting Chart - Fault Messages Displayed - Lochinvar Shield SNR200-100 Installation And Service Manual

13
Troubleshooting
Table 13E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT
Service Blk
Low 24 VAC
Watch Dog Error
Write EEProm
CRC Parameters
(continued)
DESCRIPTION
While the unit is in Service Mode, the outlet
temperature has exceeded 185°F.
120 VAC input to the main control board has
dropped below 80 VAC.
The main control board has detected an
internal fault.
The main control board has detected an
internal fault.
The main control board has detected an
internal fault.
Installation & Service Manual
TM
CORRECTIVE ACTION
• Establish a draw to remove HW heat from the
water heater.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the water heater is piped properly into the
heating system. Refer to Section 6 - System Piping
for the proper piping methods for the Shield water
heater.
• Check 120 VAC to the water heater pump motor on
a call for heat. If voltage is not present, check the
wiring back to the main control board. Replace the
main control board if necessary.
• If 120 VAC is present on a call for heat and the water
heater pump is not operating, replace the pump.
• Verify that the water heater pump is set to the proper
speed or that the water heater pump is the proper
size. Reference Section 6 - System Piping for water
heater pump specifications.
• Check 120 VAC supply to the transformer.
• Check wiring connections at the low voltage terminal
strip.
• Check the wire size/length to remote devices.
• Replace the transformer.
• Replace the main control board.
• Replace the main control board.
• Replace the main control board.
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