Displayed - Lochinvar Shield SNR150-100 Installation & Service Manual

12
Troubleshooting
Table 12E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT
Parameters
After downloading parameters from a laptop,
Progr
the main control board must be reset.
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
Blocked Drain
SW
The blocked drain switch has detected
excessive condensate build up inside the
(will retry after 5
unit.
minutes. RESET may be
pressed after condition is
corrected.)
While the unit is in Service Mode, the outlet
temperature has exceeded 185°F.
Service Blk
120 VAC input to the main control board has
Low 24 VAC
dropped below 80 VAC.
Watch Dog Error
The main control board has detected an
internal fault.
The main control board has detected an
Write EEProm
internal fault.
The main control board has detected an
CRC Parameters
internal fault.
(continued)
DESCRIPTION
Installation & Service Manual
TM
CORRECTIVE ACTION
• Press the ENTER/RESET button on the display
panel.
• Check condensate tube from unit to floor drain for
proper installation and obstructions.
• Inspect condensate trap for blockage. Clean if
necessary.
• Check for loose wiring connection at wire harness
plug.
• Bad blocked drain switch. Replace switch.
• 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 5 - 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 5 - 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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