AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 69)

TROUBLESHOOTING
7-6
KC1000 WATER HEATER TROUBLESHOOTING TABLE – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
IGN SWTCH CLOSED
DURING PURGE
1. Air/Fuel Valve not
rotating
2. Defective or shorted
switch
3. Switch wired incorrectly
4. Defective Power Supply
Board or fuse
5. Defective IGST Board
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.
3. Check to ensure that the switch is wired correctly
(correct wire numbers on the normally open terminals).
If the switch is wired correctly, replace the switch
4. Check DS1 & DS2 LEDs on Power Supply Board. If
they are not steady ON, replace Power Supply Board.
5. Check “Heartbeat” LED DS1 and verify it is blinking
ON & OFF every second. If not, replace IGST Board.
IGN SWTCH OPEN
DURING IGNITION
1. Air/Fuel Valve not
rotating to ignition
position.
2. Defective ignition switch
3. Defective Power Supply
Board or fuse
4. Defective IGST Board
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.
2. If the Air/Fuel Valve does rotate to the ignition position,
check the ignition position switch for continuity
between the N.O. and COM terminals when in contact
with the cam.
3. Check DS1 & DS2 LEDs on Power Supply Board. If
they are not steady ON, replace Power Supply Board.
4. Check “Heartbeat” LED DS1 and verify it is blinking
ON & OFF every second. If not, replace IGST Board.
INTERLOCK
OPEN
1. Interlock jumper not
installed or removed
2. Energy Management
System does not have
boiler 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.