Lennox LF25-045A

Page 1
INSTALLATION
INSTRUCTIONS
UNIT HEATERS
507930-01
3/2019
LF25-030/105 Compact Unit Dimensions.......................2
Compact Unit Parts Arrangement ...................................3
LF25-125/200 Standard Unit Dimensions ......................4
LF25-250/400 Standard Unit Dimensions ......................5
Standard Unit Parts Arrangement...................................6
Shipping..........................................................................7
Optional Accessory .........................................................7
Requirements in USA .....................................................7
Requirements in Canada ................................................7
Additional Requirements ................................................8
Unit Heater Installation ...................................................8
Combustion and Ventilation Air.......................................8
Rotation of Combustion Air Inducer - 125/150................9
Venting............................................................................9
Electrical Connections .................................................. 14
Gas Connection ...........................................................18
Leak Check ..................................................................18
Unit Start-Up ................................................................18
To Turn O󰀨 Gas to Unit ................................................19
Heating Sequence of Operations ................................19
Ignition Control LED ....................................................20
High Altitude Adjustments ............................................20
Gas Flow .....................................................................20
Gas Pressure Adjustments .......................................... 20
Limit Control Switch ......................................................21
Louver Vane Adjustment ..............................................21
Combustion Air Pressure Switch .................................21
Flame Rollout Switch ...................................................21
Service..........................................................................21
Start-Up and Performance Checklist ........................... 22
LF25
30,000 to 400,000 Btuh Series
Table Of Contents
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
WHAT TO DO IF YOU SMELL GAS:
Do not store or use gasoline or other
cinity of this or any other appliance.
formed by a qualified installer, service
agency or the gas supplier.
Do not try to light any appliance.
Leave the building immediately.
Do not touch any electrical switch; do not use
any phone in your building.
Immediately call your gas supplier from a
neighbor's
structions.
If you cannot reach your gas supplier, call the
fire department.
FIRE OR EXPLOSION HAZARD.
Failure to
ly could result in serious injury, death,
or property damage.
WARNING
Be sure to read and understand the
structions in this manual.
ation, service or maintenance can cause
serious injury, death or property damage.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal injury
or loss of life. Installation and service must be performed
by a licensed professional installer (or equivalent), service
agency or the gas supplier.
CAUTION
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.

Lennox LF25-045A Specifications

General

Brand	Lennox
Model	LF25-045A
Category	Heater
Language	English

Summary

Requirements in USA

Requirements in Canada

Unit Heater Installation

Venting

General Recommendations and Requirements

Venting must comply with NFPA 54, CSA-B149, and local codes.

HORIZONTAL VENTING

VENTING USING A MASONRY CHIMNEY

Single appliance venting prohibited

Prohibits single appliance venting into tile-lined masonry chimney without liner.

Electrical Connections

Gas Connection

Gas Supply Connection

Sizing piping, drip leg, shut-off valve, and plugged tap for gas supply.

Leak Check

Procedure for checking gas piping connections for leaks using soap solution.

Unit Start-Up

FOR YOUR SAFETY READ BEFORE LIGHTING

Safety warnings before lighting, including electric shock and gas hazards.

OPERATION OF WHITE RODGERS 36 H SERIES VALVE (FIGURE 9) AND WHITE RODGERS 36 G SERIES GAS VALVE (FIGURE 10)

Heating Sequence of Operation

To Turn Off Gas to Unit

Procedure to safely turn off the gas supply to the unit.

High Altitude and Gas Adjustments

Gas Flow and Pressure

Checking gas flow and adjusting manifold pressure.

Service Procedures

Burner and Flue Maintenance

Troubleshooting and Safety Tests

START-UP AND PERFORMANCE CHECKLIST