Optional Remote Outdoor Sensor

The outdoor sensor (X2658) may be required, especially when using Humiditrol® EDA applications. In addition to measuring and displaying outdoor temperature, the outdoor sensor provides dew point adjust- ment and control for all models. If used with this thermostat, the sensor enables optimal heating equipment operation via programmable bal- ance points. The screen will display NO OUTDOOR SENSOR until the outdoor sensor is installed, the feature is turned on in the USER SET- TINGS, in the DISPLAY INFO option. The outdoor temperature is dis- played in the information display (lower center of the screen).

NOTE − For proper operation of Humiditrol® EDA applications, the outdoor sensor MUST be installed.

In many applications, the ComfortSense® Model L7742U thermostat displays the temperature sensed by the remote outdoor sensor. With the heat pump system, the remote outdoor sensor helps determine when to turn on the second stage of heating for optimal comfort.

When the outdoor sensor is connected, the temperature displays in the information display area (below the indoor temperature display).

Memory Protection

The thermostat stores all the information concerning its programming (state, mode, program information, last temperature measured) in a nonvolatile memory.

This function avoids the loss of the state of the thermostat when a pow- er−down occurs. The only thing that might be lost is the clock, however, a lithium battery will remember clock information for as long as it has charge (approximately 30 days). When power down occurs (due to a power outage) the thermostat is able to switch off all relays. The O and B relay will maintain their last state.

Service Reminders

The user may turn on and turn off the following service reminders (all of which default to OFF) in either chronological time and/or run time and may be reset (to default) or delayed (snooze) at any time:

Replace Media Filter

Routine Sys (System) Check−up

Replace Hum (Humidifier) Pad

Replace UV Lamp

PureAirt Maintenance

NOTE − When chronological time is selected, the timer runs based on the calendar. When time is selected in run time, the timer runs based on the time the specific output is ON (e.g. Fan output for Media Filter).

When the reminder time (either calendar time or run time) has elapsed, the system displays a screen from which the user can either RESET or DELAY the reminder.

The user can reset the timer either before it has expired (i.e. reminder is set to 6 months and user decides to reset it to 6 months or change it to different value at the end of 4th month) or when the time has expired and a reminder message has been displayed.

When a reminder is turned off, the indicator will not be activated even if the timer is expired. Note that setting filter reminder to 0 (OFF) will not reset the timers, but will deactivate the filter indicator.

In the case of a power interruption:

Slithium battery has charge

tained (i.e. the counter does not recycle to zero).

Slithium battery has NO charge tained.

Page 15

ComfortSenset Model L7742U Touch Screen 7−Day Programmable Thermostat

l7742u, comfortsense 7000 series touch screen programmable thermostat specifications

Lennox International Inc. is renowned for its innovative heating, ventilation, and air conditioning (HVAC) solutions, and the ComfortSense 7000 Series Touch Screen Programmable Thermostat, model L7742U, stands as a testament to its commitment to energy efficiency and user-friendly design. This advanced thermostat combines cutting-edge technology with an intuitive interface, making it an ideal choice for homeowners looking to enhance comfort while managing energy costs.

One of the standout features of the ComfortSense 7000 Series is its large, easy-to-read, full-color touch screen display. This enables users to navigate the thermostat’s settings and programming options effortlessly. The interface is designed to provide clear visibility, even in low light conditions, ensuring that managing your home’s climate is straightforward at any time of day.

The thermostat allows for flexible programming, accommodating up to four separate time periods in a single day, which can be customized for heating and cooling settings. This programmable feature means users can optimize their HVAC usage according to their daily schedules, leading to potential energy savings and increased comfort when they need it most.

Another significant characteristic of the L7742U model is its compatibility with a wide range of heating and cooling systems. This versatility enables homeowners to integrate the thermostat with both conventional and advanced HVAC systems, including heat pumps and multi-stage units, which enhances its appeal across various applications.

The ComfortSense 7000 Series also includes smart features that allow for remote access. When connected to Wi-Fi, users can adjust their home’s temperature settings from their smartphones or tablets using the Lennox mobile app. This feature is particularly valuable for homeowners who want to make adjustments while away from home, ensuring that indoor conditions remain pleasant upon their return.

Moreover, the thermostat is designed with energy efficiency in mind. It utilizes advanced technologies, such as energy usage reports and reminders for regular maintenance checks, empowering users to take charge of their energy consumption. This can lead to reduced utility bills and a smaller environmental footprint.

In conclusion, the Lennox ComfortSense 7000 Series Touch Screen Programmable Thermostat, model L7742U, is a sophisticated yet user-friendly device that enhances the overall efficiency and comfort of home environments. Its advanced programming capabilities, smart technologies, and compatibility with various HVAC systems make it a smart choice for today’s energy-conscious homeowners. With Lennox’s commitment to quality, users can expect reliability and performance that meets the demands of modern living.