Lennox Harmony III Installation Instructions

GAS FURNACE
Page 36
505023M 08/11
TroubleshootingGas Heating Operation
3−Minutes
since completion
of last heating
demand
?
Energize W1 @
furnace; Ramp
indoor blower to
minimum CFM
setting
Discharge
air above
100°F
?
Discharge
air below heating
staging jumper
setting
?
Ramp indoor
blower to
heating staging
jumper setting
3−Minutes
minimum run time
in 1st stage
completed
?
3−Minutes
minimum run time
in 2nd stage
completed
?
No
Yes
No
Yes
No
No
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
No
De−energize
W2
Energize W2
@ furnace
Monitor
discharge air
temperature
HEATING
DEMAND
RECEIVED
BLOWER
SHUTDOWN
Yes
No
Yes
No
Yes
No
De−energize
W1 @ furnace
Hold dampers
open for 3½
minutes
Monitor
discharge air
temperature
REFER TO DISCHARGE AIR
UPPER LIMIT DIAGRAM
(Page 37) FOR UPPER LIMIT
AND DIFFERENTIAL DETAILS.
Shut down all
heat stages
Is
discharge
air at upper
limit
?
Does
discharge air
temp. meet
heating staging
differential
?
Is
discharge
air at upper
limit
?
Heating
demand
satisfied
?
Heating
demand
satisfied
?
Heating
demand
satisfied
?
Discharge
air falls to
130°F
?
No
Yes
Continuous air
delivered to
calling zones
Yes
5 min
delay
complete
?
No

Lennox Harmony III Specifications

General

Brand	Lennox
Model	Harmony III
Category	Control Systems
Language	English