AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 67)

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.