Lennox L3011C, L3021H Installation Instructions Manual

INSTALLATION

E2017 Lennox Industries Inc.

THIS MANUAL MUST BE LEFT WITH THE HOMEOWNER

Dallas, Texas, USA

FOR FUTURE REFERENCE

WARNING

This product contains a chemical known to the State of
California to cause cancer, birth defects, or other
reproductive harm.

WARNING

Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.

Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.

INSTRUCTIONS

ComfortSense® 3000 Series
Models L3011C/L3021H
Non‐Programmable
Thermostats

CONTROLS

506080-02
5/2017
Supersedes 506080-01

Table of Contents

L3011C /L3021HThermostats 1...................

General 1......................................

Shipping & Packing 1............................

Requirements 2.................................

Installation 2....................................

Thermostat Operation 3..........................

DIP Switch Settings 3...........................

Wiring Diagrams 5..............................

Thermostat model L3011C is suitable for non‐heat pump,
single-stage heat/single-stage cool applications that are
matched with a gas or electric furnace.

Thermostat model L3021H is suitable for single-stage heat
pump applications that are matched with a gas or electric
furnace as the auxiliary heat source. An optional outdoor
temperature sensor provides auxiliary heat lockout/bal
ance point operation and dual-fuel compatibility.

General

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

L3011C/L3021H Thermostats

These are non‐programmable electronic thermostats
which are easy‐to‐use, have a large, easy‐to‐read display,
and provide excellent temperature control. Both thermo
stat models also includes a programmable filter change re
minder, and a system check indicator which will notify the
user of the need for equipment service.

Shipping and Packing List

1 - Thermostat (L3011C or L3021H)
2 - Plastic wall anchors
2 - Screws

Optional Accessories

Outdoor Sensor (used with L3021H only): X2658
Wall Plate: X2659

Requirements

IMPORTANT

Read all of the information in this manual before using
this thermostat.

All wiring must conform to local and national building
and electrical codes and ordinances.

This is a 24VAC Class II voltage thermostat. Do not
install on voltages higher than 30VAC.

Be sure that power routed to the thermostat has been pow
ered off before beginning installation.

This thermostat should be used only as described in this
manual.

Do not install the thermostat on outside walls (where there is
unconditioned space on opposite side of wall) or in locations
where direct sunlight may be present.

Install thermostat about 5 feet up from the floor.

CAUTION

Do not short (jumper) across terminals on the gas
valve or at the system control to test installation.
This will damage the thermostat and void the war
ranty.

Installation

NOTE - If this thermostat is replacing an existing thermo
stat, carefully label the existing thermostat wires so that
they can be identified later.

1. If a previously‐installed thermostat exists, remove it;
if none exists, identify the location for installation (lo
cate, or install wiring as necessary). To facilitate instal
lation, enlarge the hole where the thermostat wires
protrude through the wall to about 1-1/2” wide by 3/4”
high.

2. Pull about 3 inches of the thermostat wiring through
the wall opening. Strip 1/4” of the insulation from the
ends of the thermostat wires to be used.

3. Use a screwdriver to remove the thermostat subbase
from the body. Carefully pry the subbase away from
the body along the bottom edge of the base near the
two mounting snaps; then lift the subbase upward.

4. Use the subbase as a template to mark the desired
mounting hole locations on the wall.

5. Drill two 3/16” holes at the marked locations on the
wall. Insert the provided plastic wall anchors provided
into the holes. Press the anchors into the holes until
anchors are flush with the wall.

6. Align the subbase over the plastic anchors and secure
it to the wall using the provided screws.

7. Use a small slotted screwdriver to secure all wires to
the subbase terminal block. Make thermostat connec
tions as follows:

D L3011C - See table 1 and figure 1.
D L3021H - See table 2 and figure 2.

8. Thermostat L3021H Only

D For most applications, E will be jumpered to W1. If

separate wires are not provided for both E and
W1, jumper the E terminal to the W1 terminal on
the thermostat subbase.

D For dual-fuel applications (heat pump with gas fur

nace), OR for auxiliary heat lockout applications,
the optional outdoor sensor (part number X2658)
MUST be installed.

D Connect the outdoor temperature sensor wires to

the T terminals on the subbase terminal strip. (The
sensor connections are not polarity-sensitive.)

9. After wiring is complete, thoroughly seal the hole in the
wall with a suitable material to prevent unconditioned
air in the wall space from entering the thermostat.

10. Set the thermostat DIP switches as required for the
application. See table 3 for DIP switch settings.

11. Carefully attach the thermostat to the subbase by first
engaging the hinges at the top of the unit, then pivoting
the thermostat downward until the thermostat snaps
into place.

The thermostat is now ready for operation. Turn on
power to the thermostat and refer to the appropriate
thermostat operation manual: 504,865M for L3011C
or 504,931M for L3021H.

12. Remove the clear protective film from the face of the
thermostat display.

Note: After this film is removed, some dark streaks or
lines may temporarily appear on the display. These
are normal and should disappear within a few minutes.

Removing Thermostat

The thermostat hinges on tabs on the top of the subbase.
After installation is complete, no tool is needed to remove
the thermostat from the subbase. Pivot the bottom of the
thermostat outward (releasing the snaps), then lift up to re
move.

Table 1. L3011C Terminal Designations

Terminal Description

R 24VAC

G Fan control

Y1 First stage cooling

W1 First stage heating

L Service Indicator

C 24VAC common

506080-02 5/2017

Page 2