Lennox Harmony III Installation Instructions Manual page 26

(0−off;1−on)
Code Diag LED Fault
1234
# Indicated
4 0010 Defrost while
gas heat
selected
5 1010 Discharge Air
Sensor (DAS)
detects high
heating
temperature
6 0110 Zone air
jumper not
selected
7 1110 Open or
shorted DAS
8 0001 Simultaneous
heat and cool
call from
same
thermostat
9 1001 Open
pressure
switch
10 0101 Insufficient
heating
11 1101 DAS sensed
frozen coil
12 0011 Multiple
jumper
selection
13 0111 Dual−fuel
furnace use
lock−in
505023M 04/06
Diagnostics Codes
Remedy
System detected defrost signal at W1−Def terminal block while the jump-
er is selected for the furnace. May be caused by:
S
Wrong selection for INDOOR UNIT jumper.
S
OUTDOOR UNIT terminal block misfired.
S
Zone control system failure.
Check unit installation instructions for correct wiring. If no signal is pres-
ent at W1, then replace zone control board.
This condition may occur any time the discharge probe senses air
warmer than 160_F for furnace or 135_F for heat pump. If system is in
zone mode when this code is set, the system continues in zone mode,
shuts off equipment, and runs continuous blower to satisfy demand. The
heat pump or furnace will remain off for a minimum of 5 minutes and
until the DAS senses 130_F.
Add more air to zone or redistribute zones to divide air more evenly.
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 a PIAB of
100 is required to service the zone.
Make a zone air jumper selection. If jumpers are in place, replace the
zone control board.
If system is operating, system will be forced into central mode. The com-
pressor will cycle from high to off in cooling. The compressor will cycle
from high to off in heating. The furnace will operate normally in gas heat.
Replace discharge probe. If error persists, replace zone control board.
(Or inconsistent thermostat signals) Make sure the thermostats are cor-
rectly connected to the zone control board. If error persists after you
check the thermostats and jumper selections, try another thermostat
model or brand. Demand will be ignored from the zone sending bad
signals. See Table 9.
Displayed when the pressure switch opens and does not necessarily
mean there is anything wrong. However, try increasing the air delivered
to the smallest zone. An open pressure switch will stage the heat pump
down to first stage only, if after 90 seconds the switch does not close,
the heat pump is shut off and backup heat is used to satisfy the call.
Occurs when unable to maintain desired temperature in heating. Dis-
plays code and no further action is taken.
When sensed, the condensing unit will stop and as long as the cooling
demand is present the ID blower will continue to run until the 5 minute
timed off timer expires and the discharge air sensor senses 55_F.
Each jumper block on zone control board is allowed only one jumper,
except for the system setup block. Remove extra jumper.
Heat pump was not able to maintain desired discharge air temperature;
furnace will be used to satisfy heat calls for the next 3 hours. After 3
hours, the heat pump will be used again.
Page 26
Fail-safe
(System
Shut Down)
Yes
No
No
No
No
No
No
No
No
No