Aerco KC Series Installation, Operation & Maintenance Instructions Manual page 55

12. Reset the actuator onto the valve body while
observing the ohm meter
13. If continuity is now okay, reconnect wires
#21 and #22, replace the cover plate and
reassemble the actuator to the valve body
14. If there is no continuity, replace the actuator
or switch
15. Restart the unit. If the unit sequence
resumes normal operation, proceed no
further. If the Lockout persists, proceed to
Step 16.
16. Disconnect electrical power and remove
wires #21 and #22 from the proof of closure
switch. Disconnect the 15-pin connector
from the control panel.
17. Referring to system schematic 161412 in the
Appendix, locate wires #21 and #22, check
each for continuity using an ohm meter.
18. Check for loose connectors at the proof of
closure switch end.
19. Check wires #21 and #22 at the control
panel connector for worn pins and/or proper
pin insertion.
20. Repair as necessary.
21. If connections and continuity are okay,
reconnect wires #21 and #22 to the proof of
closure switch and reconnect the 15-pin
connector to the control panel ensuring it
locks into place.
22. Replace the cover plate on the actuator and
reposition the actuator on the valve body and
lock into place using the set screws.
23. Restore electrical power to the unit.
24. Restart the unit. If the condition persists,
contact a certified Aerco Service personnel
or your local Aerco representative.
7.7.6 AIR/FUEL VALVE OPEN PROVING
SWITCH
1. Remove the air/fuel valve cover.
2. Restart the unit.
3. If the air/fuel valve rotates to its full open
position and engages the valve open proving
switch, proceed to Step 5.
TROUBLESHOOTING
4. If the air/fuel valve does not rotate, proceed
to 7.7.7.
5. Disconnect electrical power to the unit.
6. Referring to system schematic 161412 in
Appendix F, locate wires #59 and #60.
Remove wires #59 and #60 from the air/fuel
valve open proving switch, noting their
location. (The air/fuel valve open proving
switch is the one closest to the blower.)
7. Connect an ohm meter across the terminals
of the switch, where wires #59 and #60 were
located
8. Manually depress the switch and check the
ohm meter for continuity.
9. If the switch does not show continuity,
replace the switch.
10. If the switch shows continuity, disconnect the
12-pin connector from the control panel.
11. Referring to system schematic 161412 in
Appendix F, locate wires #59 and #60.
Check wires #59 and #60 for continuity.
12. Check for loose connectors, at the switch
end, of wires #59 and #60.
.
13. Check the 12-pin connector end for worn
and/or properly inserted pins.
14. If connections and continuity are okay,
replace wires #59 and #60 and rconnect the
12-pin connector to the control panel and
restart the unit.
15. If the fault persists, restart the unit and
check for AC voltage at wires #59 and #60.
16. If 120 VAC is present, go to section 7.7.3.
17. If 120VAC is not present proceed to section
7.7.5.
7.7.7 AIR/FUEL VALVE NOT ROTATING
1. Disconnect electrical power to the unit.
2. Remove the air/fuel valve cover.
3. Check for loose wires at the wire nuts
connecting the air/fuel valve wiring harness
to the stepper motor.
4. Holding the coupling between the top of the
stepper motor and the potentiometer with
your thumb and forefinger, rotate the valve.
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