Lennox International Inc Complete Lennox Thermostat Instructions and Manual for Optimal Temperature Control
Page 27

E2005 Lennox Industries Inc.

Dallas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

51M39 Merit® Series Thermostat

The Lennox Merit® Series 7 day programmable electronic

thermostat 51M39 provides excellent temperature control

and a large, easy-to-read display. This product includes a

programmable filter change reminder, an equipment

maintenance reminder, and a system check indicator to

notify the user when the equipment requires service.

Thermostat 51M39 is suitable for non-heat pump, two- stage heat/two-stage cool applications using a gas or elec- tric furnace. Also, the thermostat provides autochange- over capability.

OPERATION

MANUAL

51M39 Merit® Series

7 Day Programmable Thermostat

CONTROLS

505,068M

 

 

Litho U.S.A.

07/05

 

 

Table of Contents

51M39 Series Thermostat . . . . . . . . . . . . . . . . . . . . . . 1

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

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Initial Thermostat Power-up . . . . . . . . . . . . . . . . . . . . . 1

Buttons, Backlight, Timers & Settings . . . . . . . . . . . . 2

DAY/TIME − Set Day and Time . . . . . . . . . . . . . . . . . . 2

HEAT − Heat Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

COOL − Cool Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

AUTO − Using the Autochangeover Mode . . . . . . . . . 4

HOLD − Temperature Hold Mode . . . . . . . . . . . . . . . . 4

PROG − Thermostat Programming . . . . . . . . . . . . . . . 4

COPY − Copy a Program . . . . . . . . . . . . . . . . . . . . . . . 6

FAN − Controlling Fan Operation . . . . . . . . . . . . . . . . . 5

Displaying Outside Temperature . . . . . . . . . . . . . . . . . 6

SETTINGS − Filter /Maintenance Reminder . . . . . . . 6

Service Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Thermostat RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Removing/Installing Thermostat . . . . . . . . . . . . . . . . . 7

Default Thermostat Settings . . . . . . . . . . . . . . . . . . . . 7

Thermostat Output Table . . . . . . . . . . . . . . . . . . . . . . . 7

Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . 8

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.

Introduction

This document describes the operation of Lennox thermo-

stat 51M39. Refer to the installation manual for instructions

regarding installation and wiring of the thermostat.

Initial Thermostat Power-up

When power is initially applied to the thermostat, the dis-

play will appear as shown in figure 1.

Initial Power−Up Display

Copy tofrom MO TU WE TH FR SA SU

PROG

AM

 

 

A B C D

 

 

HOLD

PM I8:88

FAN ON

COOL SETPOINT

 

AUTO

 

 

°

 

FILTER SERVICE

 

COOL

MAINTENANCE

 

 

 

OFF

 

 

 

OUTROOM

 

AUTO

HEAT SETPOINT

EMG.

 

°

 

°

HEAT

i88

 

Hi

 

Lo

Figure 1

All display segments are momentarily activated. This oc-

curs as a normal part of thermostat initialization.

07/05

Page 1

505,068M

*2P0705*

*P505068M*

 

Page 26 Page 28
Image 27
Page 26 Page 28
Contents 51M37 Merit Series Home Screen Buttons, Backlight, Timers & SettingsDAY/TIME − Setting the Day and Time Thermostat ButtonsFAN Heat − Using the Heat ModeTurn Cool ON/OFF Cool − Using the Cool ModeEnabling and Disabling Cool Mode Cool Mode DisabledPM I036 FAN I036 FANFAN − Controlling the Fan Operation Settings − Filter/Maintenance RemindersRemoving/Installing Thermostat Settings − Balance PointService Indicator Thermostat ResetTechnical Specifications Default Thermostat SettingsMaintenance Reminder Smart Setback Recovery via DIP switch #6Equipment Protection Timers Over−Temperature ProtectionThermostat Output Table Cooling DemandsHeating Demands 51M35 Merit Series Thermostat 51M35 Merit Series505049M 5/1/05 Turn Heat ON/OFF Heat − Using the Heat Mode Cool − Using the Cool ModeEnabling and Disabling Heat Mode Heat/Cool Mode DisabledHold − Using Temperature Hold Modes 1st press I0i4 Removing and Installing Thermostat51M35 Terminal Designations Electric Heat, Auto Fan Thermostat OutputsGas Heat, Auto Fan Gas Heat, Continuous Fan51M34 Merit Series Thermostat 51M34 Merit Series505048M 5/1/05 51M34 Series 5/2 I036 FAN OFF I0i4 51M34 Terminal Designations Heat Demand Cool Demand No Demand 51M39 Merit Series Thermostat 51M39 Merit SeriesI026 Heat/Cool Mode Disabled Cooling Demand 530I030 Auto − Using the Autochangeover Mode Copy a Programmed Day to An other Day Service Indicator Flashing Displaying Outside TemperatureCheck Outside Temperature Filter Maintenance IndicatorsDefault Program Settings Time & Temp 51M39 Terminal Designations Indoor Temperature Measurement RangeOutdoor Temperature Measurement Range Autochangeover Deadband Selection via DIP switch #7Thermal-mechanical switch opens W1 and W2 at 93F+/−6F Page 51M42 Merit Series 51M42 Merit Series Thermostat−Day Programmable Thermostat 505069M 07/05 Large Heat Heating Demand FAN Auto MID Reminder Settings Display Using Fan on I026 With Electric Backup no outdoor sensor Default Program Settings − Time & TempTechnical Specifications 51M42 Terminal Designations 51M38 Merit Series Thermostat 51M38 Merit SeriesY/TIME button 51M38 Series 5/2 Hold − Using Temperature Hold Modes Repeat steps a and B for as many days as you Settings Thermostat Output Table 51M38 Terminal Designations

51M37 specifications

Lennox International Inc, a prominent player in the heating, ventilation, and air conditioning (HVAC) market, has made significant strides in innovation and technology in recent years. Among its notable offerings is the Lennox 51M37, a well-engineered component designed to enhance HVAC efficiency and reliability.

The 51M37 is primarily known for its advanced motor technology, incorporating ECM (Electronically Commutated Motor) design, which significantly reduces energy consumption compared to traditional motor systems. This motor type is key to Lennox's commitment to sustainability, as it not only maintains optimal performance but also minimizes the carbon footprint associated with residential and commercial heating and cooling tasks.

A standout feature of the 51M37 is its intelligent control system, which allows for more precise management of airflow and temperature. This technology can adapt to specific environmental conditions and consumption patterns, optimizing performance and providing substantial cost savings on energy bills. The integration of smart technology aligns with modern demands for energy efficiency and control, making the 51M37 a vital component in achieving higher energy ratings for HVAC systems.

In terms of compatibility, the 51M37 is engineered to work seamlessly with a variety of Lennox heating and cooling units, ensuring versatility for both new installations and retrofits. This compatibility enhances system integration, resulting in improved overall performance.

The construction of the 51M37 emphasizes durability and reliability, featuring high-quality materials that withstand the challenges of constant operation. Its robust design is perfect for diverse environments, ensuring that it functions reliably in both residential settings and commercial applications.

Another characteristic worth noting is the user-friendly installation process, allowing HVAC technicians to install the 51M37 with relative ease. This not only reduces labor costs but also ensures that the system can commence operation quickly without extensive downtime.

Overall, Lennox International's 51M37 embodies innovation, efficiency, and reliability in HVAC technology. With its advanced ECM motor, intelligent controls, and durable construction, it stands as a prime example of how modern HVAC solutions can lead to enhanced performance and energy savings. As the industry continues to evolve, products like the 51M37 will play a critical role in shaping the future of heating and cooling, aligning with sustainability goals and meeting the needs of consumers.
Top Page Image Contents