Lennox Harmony III Installation Instructions

HEAT PUMP
Page 22
505023M 08/11
TroubleshootingHeat Pump Heating Operation
De−energize
W1 & W2
@furnace
Discharge
air below
130ºF
?
Discharge
air above than
135ºF
?
Discharge
air above than
135ºF
?
Discharge
air 20ºF above
heating staging
jumper setting
?
Discharge
air below heating
staging jumper
setting
?
4−minute
minimum runtime
in 1st stage
completed
?
2−minute
minimum runtime
in 2nd stage
completed
?
Energize 1st compres-
sor stage; ramp indoor
blower to heating stag-
ing jumper setting
Energize next heat stages
Multiple stages stage on
and off to maintain heating
staging jumper setting
5−minutes
since completion
of last heating
demand
?
HEATING
DEMAND
RECEIVED
Shutdown
compressor
stages 1 and 2
and blower fan
Yes
No
No
Yes
No
Yes
Yes
No
Yes
No
No
Yes
No
Yes
No
Yes
No
Yes
Shutdown all
compressor stages
and electric heat
Yes
No
Monitor
discharge air
temperature
Monitor
discharge air
temperature
REFER TO DEFROST
DIAGRAM DIAGRAM
(Page 23).
Heating
demand
satisfied
?
Heating
demand
satisfied
?
Yes
5 min
delay
complete
?
No
Continuous air
delivered to
calling zones
ORDER OF STAGING:
HP stg 1 (Y1)
HP stg 2 (Y2)
Elec strip stg 1 (W1)
Elec strip stg 2 (W2)
The maximum discharge air tempera-
ture at which the heat pump/electric
heat is allowed to run is fixed at 135°F.
When the zone control system is ap-
plied to a heat pump with electric heat,
the electric heat will be staged ON to
maintain the discharge air temperature
set by the heating staging jumper posi-
tion.
5

Lennox Harmony III Specifications

General

Brand	Lennox
Model	Harmony III
Category	Control Systems
Language	English