Watts AERCO Edge CFR 3000 Operator's And Service Manual page 50

SECTION 9 TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Defective Blocked Inlet switch.
6.
Bad inlet air temperature sensor.
7.
Defective temperature sensor.
8.
Loose wire connection between
9.
the Blower and the Controller.
Defective Air-Fuel Valve
10.
potentiometer.
Hard light.
11.
Blower not running or running too
1.
slow.
Defective Blocked Inlet switch.
2.
Blockage in air filter or Blocked Inlet
3.
switch.
Blocked blower inlet or inlet
4.
AIRFLOW FAULT
ductwork.
DURING PURGE
No voltage to Blocked Inlet switch
5.
from Edge Controller.
PROBABLE CAUSES from 3 to 12 for
6.
AIRFLOW FAULT DURING IGNITION
apply for this fault.
Missing or improperly connected
7.
Blocked Flue jumper.
Blower stopped running due to
1.
thermal or current overload.
AIRFLOW FAULT
DURING RUN Blocked Blower inlet or inlet
2.
ductwork.
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Corrective Action
Turn off unit and check the continuity of the
6.
Blocked Inlet switch. If there is an erratic
resistance reading or the resistance reading is
greater than zero ohms, replace the switch.
Check the actual inlet air temperature reading
7.
and measure resistance at the Sensor Harness
connection P1. Verify that the reading conforms
to the values shown in the reference manual.
Refer to CORRECTIVE ACTION 7 and verify that
8.
the voltage conforms to the values shown in the
manual
Check wire connection from the Blower motor to
9.
the Secondary Power Panel.
Check Air/Fuel Valve position at 0%, 50% and
10.
100% open positions. The positions on the
Valve Position bar graph should match the
readings on the Air/Fuel Valve dial.
Check igniter-injector for soot or erosion of
11.
electrode. Check injector solenoid valve to
insure proper open/close operation.
Start the unit. If the blower does not run check
1.
the blower solid state relay for input and output
voltage. If the relay is OK, check the blower.
Start the unit. If the blower runs, turn off unit
2.
and check the Blocked Inlet switch for continuity.
Replace the switch if continuity does not exist.
Remove the air filter and Blocked Inlet switch
3.
and inspect for signs of blockage. Clean or
replace as necessary.
Inspect the inlet to the combustion blower
4.
including any ductwork leading up to the
combustion blower for signs of blockage.
During the start sequence, verify that 24 VAC is
5.
present between each side of the switch and
ground. If 24 VAC is not present, refer fault to
qualified service personnel.
See CORRECTIVE ACTIONS for AIRFLOW FAULT
6.
DURING IGNITION, items 3 to 12.
Check auxiliary box to be sure Blocked Flue input
7.
is jumpered and properly connected.
Check blower for signs of excessive heat or high
1.
current draw that may trip thermal or current
overload devices.
Inspect the inlet to the blower, including any
2.
ductwork leading up to the combustion blower,
for signs of blockage.
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