Honeywell CM907 - Manual (Page 18)

18 42010943-703 R1
...an explanation for householders
A programmable room thermostat is both a programmer and a room thermostat. A
programmer allows you to set ‘On’ and ‘Off’ time periods to suit your own lifestyle.
A room thermostat works by sensing the air temperature, switching on the heating
when the air temperature falls below the thermostat setting, and switching it off once
this set temperature has been reached.
So, a programmable room thermostat lets you choose what times you want the
heating to be on, and what temperature it should reach while it is on. It will allow you
to select different temperatures in your home at different times of the day (and days
of the week) to meet your particular needs.
Turning a programmable room thermostat to a higher setting will not make the room
heat up any faster. How quickly the room heats up depends on the design of the
heating system, for example, the size of boiler and radiators.
Neither does the setting affect how quickly the room cools down. Turning a
programmable room thermostat to a lower setting will result in the room being
controlled at a lower temperature, and saves energy.
The way to set and use your programmable room thermostat is to find the lowest
temperature settings that you are comfortable with at the different times you have
chosen, and then leave it alone to do its job. The best way to do this is to set low
temperatures first, say 18°C, and then turn them up by one degree each day until
you are comfortable with the temperatures. You won’t have to adjust the thermostat
further. Any adjustments above these settings will waste energy and cost you more
money.
If your heating system is a boiler with radiators, there will usually be only one
programmable room thermostat to control the whole house. But you can have different
temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on
individual radiators. If you don’t have TRVs, you should choose a temperature that
is reasonable for the whole house. If you do have TRVs, you can choose a slightly
higher setting to make sure that even the coldest room is comfortable, then prevent
any overheating in other rooms by adjusting the TRVs.
WHAT IS A PROGRAMMABLE ROOM THERMOSTAT?