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
81
of
200
TABLE 7-1. WATER HEATER TROUBLESHOOTING – Continued
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
INTERLOCK
OPEN
1. Interlock jumper not installed or
removed
2. Energy Management System does
not have unit enabled.
3. Device proving switch hooked to
interlocks is not closed.
1. Check for a jumper properly installed across the interlock
terminals in the I/O box.
2. If there are two external wires on these terminals check any
Energy Management system to see if they have the units
disabled (a jumper may be temporarily installed to see if the
interlock circuit is functioning).
3. Check that proving switch for any device hooked to the interlock
circuit is closing and that the device is operational.
LINE VOLTAGE
OUT OF PHASE
1. Line and Neutral switched in AC
Power Box.
2. Incorrect power supply transformer
wiring.
1. Check hot and neutral in AC Power Box to ensure they are not
reversed
2. Check transformer wiring, in AC Power Box, against the power
box transformer wiring diagram to ensure it is wired correctly
LOW GAS
PRESSURE
1. Incorrect supply gas pressure.
2. Defective Low Pressure Gas Switch
1. Measure gas pressure upstream of the SSOV Actuator(s) with
the unit firing. For FM gas trains, ensure it is between 4.0” W.C.
and 2 psig. For IRI gas trains, ensure it is between 4.2" W.C.
and 2 psig (see para. 2.7.1).
2. Measure gas pressure at the low gas pressure switch. If it is
greater than 2.6” W.C., measure continuity across the switch
and replace if necessary.
LOW WATER
LEVEL
1. Insufficient water level in system
2. Defective water level circuitry.
3. Defective water level probe.
1. Check system for sufficient water level.
2. Test water level circuitry using the Control Box front panel LOW
WATER TEST and RESET buttons. Replace water level
circuitry if it does not respond.
3. Check continuity of probe end to the shell, change probe if
there is no continuity.
MODBUS COMM
FAULT
Unit not seeing information from
Modbus network
Check network connections. If fault persists, contact qualified
Service Personnel.
PRG SWTCH CLOSED
DURING IGNITION
1. A/F Valve rotated open to purge and
did not rotate to ignition position.
1. Start the unit. The Air/Fuel Valve should rotate to the purge
(open) position, then back to ignition position (towards closed)
during the ignition cycle. If the valve does not rotate back to the
ignition position, check the Air/Fuel Valve calibration. If
calibration is okay, the problem may be in the Air/Fuel Valve or
the Control Box. Refer fault to qualified service personnel.
