Lennox LHT/LDT024, Installation Instructions Manual

Page: 1 / 45


2022
WARNING
To prevent serious injury or death:
1-
Lock-out/tag-out before performing maintenance.
2-
If system power is required (e.g., smoke detector mainte­
nance), disable power to blower, remove fan belt where
applicable, and ensure all controllers and thermostats are
set to the “OFF” position before
performing maintenance.
3-
Always keep hands, hair, clothing, jewelry, tools, etc.,
away from moving part
s.
Table Of Contents
Dimensions Page 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Arrangements Page 3 . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping and Packing List Page 4 . . . . . . . . . . . . . . . . . . . .
General Page 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Requirements Page 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Support Page 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Duct Connection Page 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rigging Unit For Lifting Page 6 . . . . . . . . . . . . . . . . . . . . . . .
Horizontal Air Discharge Page 6 . . . . . . . . . . . . . . . . . . . . . .
Condensate Drains Page 7 . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Piping Page 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Test Gas Piping Page 9 . . . . . . . . . . . . . . . . . . . . .
High Altitude Derate Page 10 . . . . . . . . . . . . . . . . . . . . . . . . .
Download Mobile Service App Page 10 . . . . . . . . . . . . . . . . .
Electrical Connections Page 10 . . . . . . . . . . . . . . . . . . . . . . .
Blower Operation and Adjustments Page 13 . . . . . . . . . . . .
Diagnostic Sensors Page 26 . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION
INSTRUCTIONS
LHT/LDT024
LHT/LDT036
LHT/LDT048
LHT/LDT060
2-Ton
3-Ton
4-Ton
5-Ton
HEAT PUMP AND DUAL-FUEL PACKAGED UNITS
508303-01
10/2022
Cooling Operation Page 32 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Heat Start-Up Page 34 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heating Operation and Adjustments Page 35 . . . . . . . . . . . .
Electric Heat Start-Up Page 35 . . . . . . . . . . . . . . . . . . . . . . . .
Service Page 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Factory Unit Controller Settings Page 42 . . . . . . . . . . . . . . .
WARNING
Improper installation, adjustment, alteration, ser­
vice or maintenance can cause property damage,
personal injury or loss of life. Installation and ser­
vice must be performed by a licensed professional
HVAC installer or equivalent, service agency, or the
gas supplier
RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE
Use this QR code to download the mobile service app. Follow the prompts
to pair the app with the unit control system and configure the unit. Refer to the
“Download Mobile App” section in this manual and the Setup Guide provided
with this unit. The QR code is also available in the unit control area.
The app can be downloaded from the appropriate iOS or Android store.
Look for the following icon.
Attention!