Lennox International Inc 51M37 P505048M, 51M34 Merit Series Thermostat, I8, 2P0505, General

E2005 Lennox Industries Inc.

Dallas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

51M34 Merit® Series Thermostat

The Lennox Merit® Series 5/2 day programmable electronic thermostat 51M34 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 51M34 is suitable for non−heat pump, single- stage heat/single-stage cool applications with either gas or electric furnace.

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 thermostat 51M34. Refer to the installation manual for instructions re- garding 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.

OPERATION

MANUAL

51M34 Merit® Series

5/2 Day Programmable Thermostat

CONTROLS

505,048M

05/05Litho U.S.A. Supersedes 03/05

Table of Contents

51M34 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

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

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

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

SETTINGS − Filter /Maintenance Reminder . . . . . . . 5

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

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

Removing/Installing Thermostat . . . . . . . . . . . . . . . . . 6

Default Thermostat Settings . . . . . . . . . . . . . . . . . . . . 6

Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . 7

Thermostat Output Table . . . . . . . . . . . . . . . . . . . . . . . 8

	Initial Power−Up Display
MO	TU WE TH	FR SA SU	MAINT
	I8:88		FILTER
AM			SERVICE
PM			FAN
PROG A B C D HOLD			ON
			AUTO
	ROOM	SETPOINT	SYSTEM
	°		COOL
			OFF
88		88 °
			EMG.	Hi
			HEAT	Lo

Figure 1

All display segments are momentarily activated. This oc-

curs as a normal part of thermostat initialization.

05/05	Page 1	505,048M
*2P0505*		*P505048M*