USER’S INFORMATION USER’S INFORMATION 
MANUALMANUAL
©
2020 Lennox Industries Inc. 
Dallas, Texas, USA
508002-01 
03/2020
 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 
HVAC installer or equivalent, service agency, or the 
gas supplier.
 WARNING
FIRE OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly 
could result in serious injury, death, or 
property damage.
Do not store or use gasoline or other ammable 
vapors and liquids in the vicinity of this or any 
other appliance.
Installation and service must be performed 
by a qualied installer, service agency or the 
gas supplier.
•   Do not try to light any appliance.
•   Do not touch any electrical switch; do not
•  use any phone in your building.
•   Immediately call your gas supplier from a
•  neighbor’s phone. Follow the gas supplier’s
•  instructions.
•   If you cannot reach your gas supplier, call
•  the re department.
WHAT TO DO IF YOU SMELL GAS:
SLP99DFV SERIES
VARIABLE CAPACITY
GAS FURNACE