Lochinvar ARMOR 150 - 800 Service Manual page 31

3
Troubleshooting
Table 3E (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
No Error Stored
(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.
The main control board has detected an
internal fault.
CORRECTIVE ACTION
• Establish a heating load to remove the heat from the
water heater loop.
• 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
of the Armor Water Heater Installation and Operation
Manual for the proper piping methods for the Armor
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 of the
Armor Water Heater Installation and Operation
Manual 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.
• Replace the main control board.
Service Manual
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