AERCO Innovation (G-14-2265 and above) - Manual (Page 103)

Innovation Water Heaters Installation, Operation & Maintenance Manual
CHAPTER 7 – TROUBLESHOOTING GUIDE
OMM-0078_0L AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 103 of 206
GF-128
Phone: 800-526-0288
PRI: 11/25/2014
TABLE 7-1. WATER HEATER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
HIGH WATER TEMP
SWITCH OPEN
1. Faulty Water temperature switch.
2. Incorrect PID settings.
3. Faulty shell temperature sensor.
4. Unit in Manual mode
5. Unit setpoint is greater than Over
Temperature Switch setpoint.
6. System flow rate changes are
occurring faster than units can
respond.
1. Test the temperature switch to insure it trips at its actual
water temperature setting.
2. Check PID settings against Menu Default settings in Chapter
3. If the settings have been changed, record the current
readings then reset them to the default values.
3. Using the resistance charts in Appendix C, measure the
resistance of Shell sensor and BTU sensor at a known water
temperature.
4. If unit is in Manual Mode switch to Auto Mode.
5. Check setpoint of unit and setpoint of Temperature Switch;
Ensure that the temperature switch is set higher than the
unit’s setpoint.
6. If the system is a variable flow system, monitor system flow
changes to ensure that the rate of flow change is not faster
than what the units can respond to.
HIGH WATER
TEMPERATURE
1. See HIGH WATER TEMPERATURE
SWITCH OPEN.
2. Temp HI Limit setting is too low.
1. See HIGH WATER TEMPERATURE SWITCH OPEN.
2. Check Temp HI Limit setting.
IGN BOARD
COMM FAULT
1. Communication fault has occurred
between the PMC board and
Ignition/Stepper (IGST) board 1. Press CLEAR button and restart unit. If fault persists,
contact qualified Service Personnel.
IGN SWTCH CLOSED
DURING PURGE
1. Air/Fuel Valve not rotating
2. Defective or shorted switch
1. Start the unit. The Air/Fuel Valve should rotate to the purge
(open) position. If the valve does not rotate at all or does not
rotate fully open, check the Air/Fuel Valve calibration. If
calibration is okay, the problem may be in the Air-Fuel Valve
or the Control Box. Refer to qualified service personnel
2. If the Air/Fuel Valve does rotate to purge, check the ignition
switch for continuity between the N.O. and COM terminals. If
the switch shows continuity when not in contact with the cam
replace the switch.