Honeywell thermostat ST9400C 7 Day 2 Channel Programmer User Manual
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11 OPERATING YOUR ST900C The Extra Hour Function (for Heating and/or Hot Water) The EXTRA HOUR buttons allow you to switch the heating or hot water ON for up to 3 extra hours without altering the programme. Pressing either button once will give one extra hour. The LoT™ Display will display the message ‘+ 1 HOUR’, to confirm the button has been pressed. When the green INDICATOR LAMP is OFF, pressing an EXTRA HOUR button switches the heating or hot water ON for just one hour....
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12 FINE TUNING YOUR ST900C Changing from AM/PM Time Display to the 2 Hour Clock Your ST9400C can operate on the 12 hour AM/PM or 24 hour clock formats. To change the format, ensure the slider is in the RUN position then press and hold the and buttons together for about 2 seconds. Ignore the ‘NOT VALID’ message that will appear briefly. All the displayed times will be automatically changed to the new format. Repeating this procedure will change the clock display back to the...
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1 FINE TUNING YOUR ST900C To Enter Installer Mode: a. Ensure the slider is in the RUN position, then press and hold and buttons together for 8 seconds. Ignore the ‘NOT VALID’ message that is displayed for a few seconds. The message ‘SET UP MENU’ will show briefly, followed by ‘SET INSTALLER OK ?’ b. Press the button to take you into the Installer Mode Parameter Menu. c. Parameter 1 is now available to change. This is to allow you to change the clock format...
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1 FAQ AND TROUBLESHOOTING How do I set the time only, if the ST900C clock is not correct? Your ST9400C contains a very accurate digital clock that is factory pre-set. Should you ever need to change the time, just follow this procedure: a. Move the slider to the DAY/TIME position. b. Keep pressing the green button until the message ‘SET THE TIME’ is displayed. To change the time, press the or buttons until the correct time is shown. The message ‘IS TIME...
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1 SymptomPossible CauseRemedy ST9400C has a blank LCD displayNo power to the heating systemCheck that there is power to the heating system Fault in ST9400CCall Installer ST9400C indicates that Heating and/or Hot Water are ON, but radiators are cold and/or taps are running with cold water. Temperature controls are switched off or set too low Check that the temperature controls in the system are set to appropriate levels Boiler or other system controls have malfunctioned Call Installer ST9400C shows...
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1 MINI-PROGRAMMER OPERATING INSTRUCTIONS You need only refer to this section if: • The Mini-Programmer box is ticked on the Contents page of this booklet, or • The ST9400C Configuration Data (page 18) indicates it is set as a Mini- Programmer. What is a Mini-Programmer? In a poorly controlled gravity circulation hot water system, whenever the boiler comes on to service the heating, there will inevitably be some circulation though the hot water storage tank, which will then...
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1 Disabling / Enabling Time Periods To disable any of the time periods ON 1 to OFF 1, ON 2 to OFF 2, or ON to OFF , simply set the ON time and its paired OFF time to the same time, and the programme will just ignore them. To re-enable the time period, simply set the two ON and OFF times to be different. Choosing the Operating Mode In a Mini-Programmer, some Operating Modes are not possible. For example, HEATING in AUTO mode and HOT WATER in OFF mode is not allowed....
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150022737-005 A CONFIGURATION & SERVICE DATA Configurable FeaturesOptionsInstaller Configured (tick appropriate box) 24hr or am/pm clock displayam/pm display 24hr display Display backlight operationOff On if button pressed On continuously Automatic time changeEnabled Disabled 1-day or 5/2-day or 7-day operation1-day operation 5/2-day operation 7-day operation Number of ON/OFFs per day2 on/offs per day 3 on/offs per day Default programmeA = standard b = at home C = economy Set as Mini-Programmer...