AERCO KC Series Equipped with C-More version 3.04 - Manual (Page 71)

TROUBLESHOOTING
7-4
KC1000 WATER HEATER TROUBLESHOOTING TABLE – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
FFWD TEMP
SENSOR FAULT
1. Loose or broken
wiring.
2. Defective Sensor.
3. Incorrect Sensor.
1. Inspect feed forward (BTU transmitter) sensor for
loose or broken wiring.
2. Check resistance of sensor to determine if it is within
specification.
3. Ensure that the correct sensor is installed.
FLAME LOSS
DURING RUN
1. Worn Flame Detector
or cracked ceramic.
2. Defective Differential
Regulator.
3. Poor combustion
calibration.
4. Debris on burner.
5. Blocked condensate
drain.
1. Remove and inspect the Flame Detector for signs of
wear or cracked ceramic. Replace if necessary.
2. Check gas pressure readings using a gauge or
manometer into and out of the Air/Fuel Valve to
ensure that the gas pressure into and out of the valve
is correct.
3. Check combustion calibration. Adjust as necessary.
4. Remove the burner and inspect for any carbon or
debris. Clean and reinstall.
5. Remove blockage from condensate drain.
HEAT DEMAND
FAILURE
1. The Heat Demand
Relays on the
Ignition/Stepper
(IGST) board failed to
activate when
commanded
2. Relay is activated
when not in Demand
1. Press CLEAR button and restart the unit. If the fault
persists, replace IGST Board.
2. Defective relay. Replace IGST Board.
HIGH EXHAUST
TEMPERATURE
1. Defective exhaust
sensor.
2. Carboned heat
exchanger due to
incorrect combustion
calibration
1. Measure the actual exhaust temperature and
continuity of the exhaust sensor. If the exhaust
temperature is less than 500 o F and the exhaust
sensor shows continuity replace the sensor.
2. If exhaust temperature is greater than 500 o F, check
combustion calibration. Calibrate or repair as
necessary.
HIGH GAS
PRESSURE
1. Incorrect supply gas
pressure.
2. Defective Supply
Regulator or Wrong
Style Regulator
1. If using a non-lock up style regulator for the gas
supply, measure static gas pressure downstream, it
should be 14”WC or less. Adjust as necessary.
2. If gas supply pressure cannot be lowered, a lock-up
style regulator may be required or the supply regulator
may be defective.