Recent content by programmerstress2

Does anyone have Document EN0R8542 for the Honeywell ST6400S programmer? The one that tells you the security key sequence that gives access to the Installer Mode by using the buttons and sliders on the controller of the ST6400S? Or alternatively, the sequence alone would be much...

I also have a Honeywell ST6400S. (As with other people in the thread, I'm a homeowner and our heating system was installed a year ago. Apparently it has gone into the "Off - Service due" mode because the programmer is designed for landlords.) The service is going to happen in 2 weeks, but...