AERCO Innovation (G-10-1350 to G-11-0563) - Manual (Page 79)

Chapter 7 Innovation Series Water Heaters
GF-128
Troubleshooting Guide USER MANUAL OMM-0079_0B
PR1 - 07/21/11 AERCO International, Inc.
· 100 Oritani Dr. · Blauvelt, NY 10913 · Ph: 800-526-0288
Page 79 of 200
TABLE 7-1. WATER HEATER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
HIGH GAS
PRESSURE
1. Incorrect supply gas pressure.
2. Defective SSOV Actuator.
3. Defective High Gas Pressure Switch
1. Check to ensure gas pressure at inlet of SSOV is 2 psig
maximum.
2. If gas supply pressure downstream of SSOV Actuator cannot be
lowered, to 1.5” W.C. using the gas pressure adjustment screw
(see para. 4.3, step 10), the SSOV Actuator may be defective.
3. Remove the leads from the high gas pressure switch and
measure continuity across the common and normally closed
terminals with the unit not firing. Replace the switch if it does
not show continuity.
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 the
Appendix. If the settings have been changed, record the current
readings then reset them to the default values.
3. Using the resistance charts in the 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.