AERCO KC1000 Heater Mar 2011 - Manual (Page 72)

TROUBLESHOOTING
7-8
KC1000 WATER HEATER TROUBLESHOOTING TABLE – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
(continued) 4. Defective Power Supply
Board or fuse
5. Defective IGST Board
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.
PRG SWTCH OPEN
DURING PURGE
1. Defective purge switch.
2. No voltage present at
switch.
3. Switch wired incorrectly.
4. Defective Power Supply
Board or fuse
5. Defective IGST Board
1. If the air-fuel valve does rotate, check the
purge switch for continuity when closing.
Replace switch if continuity does not exist.
2. Measure for 24 VAC from each side of the
switch to ground. If 24VAC is not present, refer
fault to qualified service personnel.
3. Check to ensure that the switch is wired
correctly (correct wire numbers on the normally
open terminals).
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.
REMOTE SETPT
SIGNAL FAULT
1. Remote setpoint signal not
present:
Not yet installed.
Wrong polarity.
Signal defective at source.
Broken or loose wiring.
2. Signal is not isolated
(floating) if 4 to 20 mA.
3. Control Box signal type
selection switches not set
for correct signal type
(voltage or current).
1. Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and
boiler.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is
set correctly for the type of signal being sent.
Check control signal type set in Configuration
Menu.
RESIDUAL
FLAME
1. SSOV not fully closed.
2. Defective Flame Detector.
1. Check open/close indicator window of Safety
Shut-Off Valve (SSOV) and ensure that the
SSOV is fully closed. If not fully closed, replace
the valve and or actuator.
Close gas shut-off valve downstream of SSOV.
Install a manometer or gauge in a gas test port
between the SSOV and the gas shut off valve.
If a gas pressure reading is observed replace
the SSOV valve and or actuator.
2. Replace Flame Detector.
SSOV FAULT
DURING PURGE
1. See SSOV SWITCH OPEN