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WHAT IS A TIMER?
General Description
Your Honeywell ST9100S provides timing control for your central heating system,
letting you set ON and OFF periods to suit your own lifestyle.
The ST9100S does not directly control the temperature but works together with other
temperature controls, such as room thermostats, to control your heating system in
your home.
ST9100S has 1-day programming and 2 on/off periods per day, making it very simple
to use.
ST9100S also has a Boiler Service Reminder / Shut-down feature, which helps
ensure your gas boiler is regularly serviced in compliance with UK Gas Safety
Regulations. For more details see pages 16, 17.
The following instructions explain how to programme and use the ST9100S to provide
the most home comfort at the least cost.
The way to use a Timer
Think about the time periods when you are typically in the house and when you are
not. These are the times you should use as the basis for the programmes. It will be
necessary to allow some heat-up time for the heating system after periods when it
has been off – this would typically be 1 - 1½ hours, depending on your house and
your preferences.
Other features are commonly available on the Timer to enhance comfort and
convenience, for example, OVERRIDE, EXTRA HOUR, and MODE buttons.
A typical use of the OVERRIDE feature is when you return home unexpectedly for
the rest of the day and the heating is off. Just press the OVERRIDE button and the
heating will come on until the next programme time, at which point it will follow the
normal programme. The advantage here is that you do not have to remember to
switch off because the normal time programme does this for you.
A typical use of the EXTRA HOUR button would be if you returned to the house for
a short period when t he heating was off. Pressing the EXTRA HOUR button gives
you 1, 2, or 3 hours of heating, exactly when you need it. Another typical use is when
the heating is already on and you want it to stay on a little longer - just press EXTRA
HOUR and, for that day only, an hour will be added to the end of the time at which
heating normally goes off.
The MODE button allows you to select how you want to operate your heating. The
most obvious use is to switch heating OFF during the summer months, but you may
also use this feature if you take a mid-week day off work, you can then set the MODE
to ONCE to keep the system ON during the day from the first programmed ON time
till the last programmed OFF time.
