Watts Aerco Benchmark OMM-0117 Operation And Maintenance Manual page 65

Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
FAULT
INDICATION
Blower not running or running too slow.
1.
Defective Blocked Inlet switch.
2.
3. Blockage in air filter or Blocked Inlet switch.
AIRFLOW
FAULT
Blocked blower inlet or inlet ductwork.
4.
DURING
PURGE
No voltage to Blocked Inlet switch from C-More
5.
Controller.
6. Probable Causes items 3 to 12 for AIRFLOW
FAULT DURING IGNITION apply for this fault.
1. Blower stopped running due to thermal or
current overload.
Blocked Blower inlet or inlet ductwork.
2.
Blockage in air filter or Blocked Inlet switch.
3.
AIRFLOW
FAULT
4. Defective Blocked Inlet switch.
DURING RUN
Combustion oscillations.
5.
Probable causes from 3 to 16 for AIRFLOW
6.
FAULT DURING IGNITION applies for this
fault.
OMM-0118_B • GF-203 • 5/9/2019
PROBABLE CAUSES
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
CORRECTIVE ACTION
Start the unit. If the blower does not run check the blower solid
1.
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 and check the
2.
Blocked Inlet switch for continuity. Replace the switch if continuity
does not exist.
Remove the air filter and Blocked Inlet switch and inspect for signs
3.
of blockage. Clean or replace as necessary.
Inspect the inlet to the combustion blower including any ductwork
4.
leading up to the combustion blower for signs of blockage.
During the start sequence, verify that 24 VAC is present between
5.
each side of the switch and ground. If 24 VAC is not present, refer
fault to qualified service personnel.
See AIRFLOW FAULT DURING IGNITION Corrective Actions
6.
items 3 to 12.
1. Check combustion blower for signs of excessive heat or high
current draw that may trip thermal or current overload devices.
Inspect the inlet to the combustion blower, including any ductwork
2.
leading up to the combustion blower, for signs of blockage.
Remove the air filter and Blocked Inlet switch and inspect for signs
3.
of blockage, clean or replace as necessary.
Verify that 24 VAC is present between each side of the switch and
4.
ground. If 24 VAC is not present at both sides, replace switch.
Run unit to full fire. If the unit rumbles or runs rough, perform
5.
combustion calibration.
6. See CORRECTIVE ACTIONS from 3 to 12 for AIRFLOW FAULT
DURING IGNITION.
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