AERCO KC1000 Water Heater July 2011 - Manual (Page 70)

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.