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Honeywell ST9400C 7 Day Programmer

Posted: Mon Oct 07, 2024 12:10 pm
by Hansel
I have a Honeywell ST9400C 7 day programmer & have realised it is coming on at times prior to those I have set on the timer. I now realise this must be to do with the Installer parameters.

I have tried to follow the instructions:
To Enter Installer Mode:a. Ensure the slider is in the RUN position, then press ok & minus buttons and hold 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 'SETINSTALLER OK ?' which are easy enough to change, BUT after the NOT VALID message, I am not getting the SET UP MENU & cannot proceed.

Please can anyone assist?