Lennox Harmony II Zone Control System Installation Instructions Manual page 36

LED Display
Diags
Service Light
(Control Center)
(Control Panel)
Off On
Code #8
DIAG
1
DIAG
2
DIAG
3
DIAG
4
FLASHING
Code #9
DIAG
1
DIAG
2
DIAG
3
DIAG
FLASHING
4
Code #10
DIAG
1
DIAG
2
DIAG
3
DIAG
FLASHING
4
Code #11
DIAG
1
DIAG
2
DIAG
3
DIAG
FLASHING
4
Code #12
DIAG
1
DIAG
2
DIAG
3
DIAG
FLASHING
4
Table 8
Fail safe Fail-safe
Error
(System Shut
Description
Down)
Zone Air Jumper No
Control Panel
No
Error
Thermostat No
Discharge Air
Probe Has Sensed
No
Discharge Air Less
Than 0_F.
Discharge Air
Probe Has Sensed
Discharge Air No
Warmer Than
150_F.
Page 36
Remedy
1) Air selected for fewer than two zones or
2) No air is selected for zone 1 or
3) If a zone air selection jumper is left off of a zone that issues
a heat or cool demand. In this case the system will assume that
95% air is required to service the zone.
Make a zone air jumper selection. If jumpers are in place, re-
place the control center.
Simultaneous HEAT/COOL or ZONE/OFF commands re-
ceived from the control panel. Control panel will revert to Auto
changeover, Central control, and Fan Auto if this occurs.
1) Make sure the control panel is correctly wired to the control
center.
2) If the error is still reported, replace the control panel.
3) If the error is still reported, replace the control center.
NOTE− A general control panel failure or loss of connection will
not be reported as an error.
1) Simultaneous heat/cool from any stat or
2) Inconsistent thermostat signals.
See Table 2.
Demand will be ignored from the zone sending bad signals.
Make sure the thermostats are correctly connected to the control
center. Make sure heat pump thermostats are not being used if the
G21V or GAS INDOOR UNIT jumper has been selected. If error
persists after you check the thermostats and jumper selections, re-
place the control center or try another model or brand of thermo-
stat.
This condition should not occur, no matter how cold the probe.
If system is operating, system will be forced into central mode.
The compressor will cycle from high to off in cooling. The com-
pressor will cycle from low to off in heating. The furnace will op-
erate normally in gas heat or FM21 systems.
Replace discharge probe. If error persists, replace the control
center.
This condition will occur any time the discharge probe senses
air warmer than 150_F. This error is locked out (should not oc-
cur) when running a gas furnace or during the cool down phase
after running gas heat or electric strip heat. If system is in zone
mode when this code is set, the system will continue in zone
mode.
Replace discharge probe. If error persists, replace the control
center.