Aerco Benchmark G-00-711, User Manual

Page: 52 / 79

TROUBLESHOOTING
8-12
17. Referring to system schematic 161453 in
Appendix H, locate wires #148 and #149,
check each for continuity using an
ohmmeter.
18. Check for loose connectors at the proof of
closure switch end.
19. Check wires #148 and #149 at the control
panel connector end for worn pins and/or
proper pin insertion.
20. Repair as necessary.
21. If connections and continuity are okay,
reconnect wires #148 and #149 to the proof
of closure switch and reconnect the 1 "
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 setscrews.
23. Reconnect AC power to the unit.
24. Start the unit. If the condition still persists,
proceed to section 8.6.6.
8.7.6 AIR/FUEL VALVE OPEN, PROVING
SWITCH
1. Remove the air/fuel valve cover.
2. Start the unit.
3. If the air/fuel valve rotates to its full open
position, and engages the air/fuel valve
open switch, proceed to step 5.
4. If the air/fuel valve does not rotate, proceed
to section 8.6.7.
5. Disconnect AC power to the unit.
6. Referring to system schematic 161453, in
Appendix H, locate wires #171 and #172.
Remove wires #171 and #172 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 #171 and #172
were located
8. Manually depress the switch and check the
ohmmeter for continuity.
9. If the switch shows continuity, proceed to
Step 11.
10. If the switch does not show continuity,
replace the switch.
11. Disconnect the 1 ¼" connector from the
control panel.
12. Referring to system schematic 161453 in
Appendix H, locate wires #171 and #172.
Check wires #171 and #172 for continuity.
13. Check for loose connectors at the switch
end of wires #171 and #172.
14. Check the 1 ¼" connector end of wire #171
and #172 for worn and/or improperly
inserted pins.
15. If connections and continuity are okay,
reconnect wire #171 and #172 to the air/fuel
valve open switch. Reconnect the 1 ¼"
connector to the control panel and start the
unit.
16. If the fault still persists, remove the cover
from the combustion safeguard.
17. Measure the AC voltage between terminal 6
and terminal 2 after starting the unit.
18. If 120VAC is present between terminals 6
and 2, but the fault persists replace the
combustion safeguard.
8.7.7 AIR/FUEL VALVE NOT ROTATING
1. Disconnect AC 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.
NOTE:
Do not rotate the air/fuel valve with power
applied to the unit.
5. If the air/fuel valve does not rotate or is
extremely difficult to rotate, replace the
air/fuel valve.
6. Disconnect the 1 ¼" connector from the
control panel. Referring to schematic