Aertrim Maintenance And Troubleshooting - Watts Aerco Benchmark Series Operation And Service Manual

Benchmark Platinum-Edge: Operation-Service Manual
SECTION 9 – AERTRIM OPERATION

9.6 AERtrim MAINTENANCE and TROUBLESHOOTING

The AERtrim system, which maximizes blower efficiency, depends on the O
AERtrim system needs only minimal maintenance. It is recommended that you inspect the
oxygen sensor for accuracy every 12 months by comparing it to a sensor reading from a
properly calibrated flue analyzer. This is strongly advised because contaminated air or gas
supplies may cause impurity buildup and shift the calibration point. An offset value of ±3.0% can
be entered in the O2 Offset parameter in the AERtrim Settings screen (Main Menu 
Advanced Setup  Performance  AERtrim  AERtrim Settings) to correct the reading
during manual calibration. If the sensor has a large amount of offset, a replacement may be
required soon.
Occasional software updates to the device may be required.
TABLE 9-1: AERtrim General Warnings
Warning
O2 Percentage Low
O2 Sensor Malfunction
Warning 02 Level High
O2 Sensor Out Of
Range
O2 Warning Service
Required
OMM-0137_D • GF-211 • 7/16/2019
Cause
O Levels less than 2% for more
2
than 30 seconds (auto-reset when
valve comes back in range}
Levels less than -4% or more
O
2
than 24% for more than 10 seconds
{manual clearing of this fault is
required}
O Levels > 9% and < 24% for more
2
than 30 seconds {auto-reset when
value comes back in range}
Sensor auto calibration offset
required is more than ±3%
If the O level is outside of its limits
2
for more than 5 minutes.
For example:
1) Reading < Lower Limit
& Blower Voltage = BV Limit
OR
2) Reading > Upper Limit
& Blower Voltage = BV Limit
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
sensor. The
2
Possible Solutions
Dirty filter or poor combustion
calibration – recalibrate unit
O Offset too low – Increase
2
Offset value
Bad Sensor-Replace
Bad Sensor-Replace
Communication Issue – check
wires and connections
Gas Pressure Regulator or Air
Blower Problem, or bad
Combustion Calibration
O Offset too high
2
Bad Sensor-Replace
Reset Unit-Recalibrate Sensor
Bad Sensor-Replace
Bad ECU-Replace (Rare)
Gas Supply, Air Filter, or Air
Blower issue
Bad Sensor-Replace
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