Honeywell CM921 manual Using the Special Functions, Temperature Override, Holiday Function

Page 10

opERATING THE CM921

•Temperature Override

During normal operation (AUTO mode) the programmed temperature can be

adjusted manually by pressing the or buttons. The ‘target‘ temperature

will be displayed and lash for 5 seconds – during this time the or buttons can be used to modify the set value.

Note: This temperature override is cancelled at the next programmed temperature change.

Using the Special Functions

•HOLIDAY Function

The holiday function allows you to set a constant temperature (default = 10°C) for a speciied number of days (from 1 - 99 days). This lets you save energy and related costs when you are away from home, but resumes normal operation on the day of your return.

To set the Holiday function:

a.Move the slider switch to the AUTO or MAN position.

b.Press the button to display the holiday days counter and temperature setting, along with the holiday indicator .

c.The day after the current day will be selected and ‘RETURN DATE OK?’ will be

displayed. Press the or time buttons to set the holiday time (1 – 99 days). Note: (The day and date will update according to the number of days selected).

d.Press the green button to conirm the setting.

e.‘CHANGES SAVED’ will be displayed for a moment followed by ‘TEMP OK?’.

Press the or buttons to set the holiday temperature (5°C - 35°C)

f.Press the green button to conirm the setting. ‘HOLIDAY MODE’ will now be displayed on the screen until the return date is reached or the holiday mode is cancelled.

The thermostat will now control to the new temperature for the set number of days that your home is vacant. At midnight the holiday counter will be reduced by one until the selected number of days have passed. The thermostat will then return to normal operation as set by the slider switch position (AUTO or MAN position). To cancel the

HOLIDAY setting or to exit the function at any time press the button a second time or move the slider switch to a different position.

9

Page 9 Page 11
Image 10
Page 9 Page 11
Contents CM921 User Guide Plumbnation.co.uk Controls Layout Installing the Batteries To install the BatteriesRunning the Built-in Heating Program Setting the Date and TimeTo set the Date and Time Reviewing the Heating Program Built-in Heating ProgramModifying the Heating Program To press or buttons To enable time periods To disable time periodsDisabling / Enabling Time Periods Adjusting the Time Choosing the Operating ModeDuring Normal Operation Holiday Function Using the Special FunctionsTemperature Override To set the Holiday functionChanging the User Parameters To change any of these user’s parametersIi Reset the built-in program to the factory default Iii Enable or disable summer/winter time changeTroubleshooting Guide Symptom Possible Cause RemedyCheck that there is power to the heating system How do I set one temperature for the whole day? What is Optimum Start?Wall bracket HC60NG Relay Box Controls LayoutCan I use my CM921 to control my air-conditioning system? An explanation for householders Following explanation applies to heating applications only42011077-103 R1

CM921 specifications

The Honeywell CM921 is a versatile and highly efficient programmable room thermostat designed to enhance comfort and energy management in residential and light commercial applications. This product exemplifies modern heating control technology, making it an excellent choice for users looking to optimize their heating systems while maintaining user-friendly operation.

One of the key features of the CM921 is its ability to program multiple heating schedules. Users can customize settings for different days of the week, allowing for unique heating profiles that can adapt to varying daily routines. This programming capability helps to reduce energy consumption by ensuring that heating is only active when needed, ultimately lowering energy bills.

The CM921 is equipped with an advanced, easy-to-read digital display that provides clear and concise information about the current room temperature and the set temperature. This intuitive interface simplifies user interaction, enabling quick adjustments when necessary. Additionally, the thermostat features a backlit screen, which facilitates usage even in low-light conditions.

Another notable technology integrated into the Honeywell CM921 is its compatibility with various heating systems. It supports both conventional and combi boiler types, making it a flexible solution for diverse heating requirements. The thermostat can also be connected to a 2-wire system, providing an easy installation process and reducing the need for complex wiring modifications.

Energy-saving features are a significant characteristic of the CM921. The thermostat includes an intelligent frost protection setting, which ensures that the temperature does not fall below a pre-defined level when the home is unoccupied for extended periods. This prevents pipes from freezing and potential damage to the system. Furthermore, the device offers a 'holiday mode', allowing users to save energy during extended absences by automatically adjusting the heating schedule.

In terms of characteristics, the Honeywell CM921 boasts a sleek and modern design, ensuring it fits seamlessly into any home décor. Its compact size makes it suitable for installation in various locations, providing flexibility for homeowners.

Overall, the Honeywell CM921 stands out for its blend of advanced technology, user-friendly features, and energy efficiency. It is an ideal solution for anyone seeking to improve their home’s heating management while enjoying comfort and convenience.
Top Page Image Contents