Lennox Harmony III Installation Instructions

DUAL FUEL
Page 49
HARMONY IIIT ZONE CONTROL SYSTEM
TroubleshootingDischarge Air Upper Limit & Differential Temperatures
Discharge air upper limit is
160ºF unless 140F DAS
jumper installed
To / from the
appropriate
gas heating or
dual fuel
diagram
Furnace
energized
No
Yes
No
Yes
No
Monitor
discharge air
temperature
Is
discharge
air at upper
limit
?
3−minute
minimum run-
time com-
pleted
?
Yes
Differential is 20ºF above
heating staging jumper
setting with the following
exception:
Differential is 15ºF if the
140F DAS jumper is in
place on PIAB 1 terminals
and heating staging jump-
er is on 120 or 130.
Does
discharge air
temp. meet
heating staging
differential
?

Lennox Harmony III Specifications

General

Brand	Lennox
Model	Harmony III
Category	Control Systems
Language	English