Lochinvar Shield SNR150-100 - Manual (Page 71)

71
13
Troubleshooting
(continued)
Table 13E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT DESCRIPTION CORRECTIVE ACTION
Parameters
Progr
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
After downloading parameters from a laptop,
the main control board must be reset.
• Press the ENTER/RESET button on the display
panel.
Blocked Drain
SW
(will retry after 5
minutes. RESET may be
pressed after condition is
corrected.)
The blocked drain switch has detected
excessive condensate build up inside the
unit.
• 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.
Service Blk
While the unit is in Service Mode, the outlet
temperature has exceeded 185°F.
• 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.
Low 24 VAC 120 VAC input to the main control board has
dropped below 80 VAC.
• 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.
Watch Dog Error
The main control board has detected an
internal fault.
• Replace the main control board.
Write EEProm The main control board has detected an
internal fault.
• Replace the main control board.
CRC Parameters The main control board has detected an
internal fault. • Replace the main control board.
Installation & Service Manual TM