Honeywell Digital Timeswitch 24 Hour Single Channel ST9100S1007

The Honeywell ST9100S1007 is a 24-hour single channel digital timeswitch with a service interval reminder, supplied as part of Honeywell's residential heating controls range. It controls one heating or hot water circuit, switching it on and off to a set daily schedule rather than running continuously. Two on/off periods per day are available, so the circuit can be timed around occupancy instead of left running.

Setup is carried out on the unit itself. The large, high-contrast display is readable from a distance, and on-screen instructions give feedback as settings are entered, which keeps programming quick on a first fix or a straight swap.

• The heating or hot water circuit does not switch on at the programmed times
• The circuit stays on permanently and ignores the schedule
• The display is blank, flickering or unreadable
• Buttons do not respond, or settings are lost after programming
• The service interval reminder cannot be reset or cleared

• Confirm the existing timeswitch part number and the wiring arrangement at the wallplate before ordering.
• Check the appliance model against the compatibility list below.
• Cross-reference the alternative part number 4201070 when matching against older documentation.
• This item is not classified as a gas part.