Lochinvar Shield SWR125 Installation & Service Manual page 76

12
Troubleshooting
Table 12F (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT
OUTLET SENSOR
FAULT
(will require a manual
reset once the condition
has been corrected.
Press the RESET
button on the display to
reset.)
INLET SENSOR
FAULT
(will require a manual
reset once the condition
has been corrected.
Press the RESET
button on the display to
reset.)
SET POINT MET
ANTI-CYCLING
DELTA T HIGH
76
DESCRIPTION
One or both of the outlet sensors has
opened or shorted.
The inlet sensor is open.
The temperature has reached the set point
+ 10°F.
The main control board has received a call
for heat too quickly after the previous call for
heat has ended.
The temperature rise across the heat
exchanger has exceeded the set parameters
for the water heater.
The fan speed is being limited due to the
temperature rise across the heat exchanger
exceeding 55°F.
Installation & Service Manual
CORRECTIVE ACTION
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
• Measure the resistances of the sensors and compare
the resistances to the tables on page 70. Replace if
necessary.
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
• None
• The control board will release the call for heat after 60
seconds.
• The control board will release the call for heat if the
outlet temperature drops 10°F.
• 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 for 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 pump is the proper size.
Reference Section 5 - System Piping for water heater
pump specifications.