53
5.3.
Zoning System with Dual Fuel Troubleshooting - Option 3
5.3.1. Troubleshooting Diagram
Do dampers respond to demand? 0
volts AC = open. 24 volts AC =
closed. Dampers should drive closed
when 24 volts is jumpered to damper
motor.
Is wiring correct & in good condition?
Are thermostats wired correctly?
Does zone control system respond appropriately to demand?
tion relays may need to be used.
24VAC supplied to each thermostat terminal R from zone control system?
Check each thermostat for output signal when calling. Heating output W1? Cooling output Y1?
Error code present?
shooting/diagnostic
section of this
manual.
ing?
Does outdoor unit respond to demand?
Is it operating properly?
Test Defrost. Does outdoor unit initiate and
terminate defrost correctly?
Check defrost tempering switch, if installed.
Does zone control system respond
appropriately during defrost?
Are appropriate outputs energized in
response to demand?
Does zone control system energize appropriate outputs? During Cooling? During
Heating? During Defrost? During Emer. Heating?
24VAC from furnace transformer to R?
Does indoor unit respond to outputs? Cooling? Heating? Defrost? Emer. Heating?
Does blower speed change as zone demand changes? If no, does DS output vary
from 0 to 25VDC?
Line Voltage to transformer?
24VAC from transformer to zone control panel?
Are all wire connections good? Are all wire connections correct?
Pressure Switch installed. in correct position?
Does switch open when high pressure condition is simulated (temporarily
blocking airflow in heating mode)?
tion is simulated (temporarily disconnecting switch simulates high pressure).
Balance Point Sensor Installed and correctly wired?
Contacts close on temperature fall?
DAMPERS
Heating
Cooling
120
VAC
24
VAC
THERMOSTATS
rectly?
Only 1 jumper per Zone?
er Settings
NOTE:
Zone 1 may have a second
jumper on 140F DAS pins
)
Has 140F DAS jumper been
installed
Are continuous & heating air
ly? On heat pumps, Heating
Air Reduction must be 0%.
ate speed reduction? If no,
placing zone control panel.
Have heating and cooling
staging jumpers been set
eration?
PRESSURE
SWITCH
Y R B
BALANCE
POINT
SENSOR
R
C
Y1
Y2
O
W1
R
G
W1
W2
C
DS
Y1
Y2
HEAT PUMP
VARIABLE
SPEED
FURNACE
DT2 (S89)
tional, for
defrost
tempering
kit)
Is discharge
probe installed?
Is probe located
in discharge air
rectly?
DISCHARGE
AIR SENSOR
HUMIDITROL ZONING
ACCESSORY CONTROL
“C” connected
to “C”?
Fuses OK?
TO FURNAC
E
POWER
SUPP
LY
Verify Furnace jumpers/
links cut or removed
(see Pages 29 - 25)
Verify NO connections
made to Y1 or Y2.
Air
reduction
jumper
settings -
page 9.
ZONE PANEL TRANSFORMER
Figure 34. Option 3 - Typical Lennox Heat Pump and Lennox Variable-Speed Gas Furnace (Dual Fuel) (Troubleshooting
Summary of Contents for Harmony III
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