Honeywell heating systems with a combination boiler or added zones with no room thermostat. The existing wiring can be used to provide boiler interlock by fitting Sundial RF2 Pack 1. This has a timer to control heating and a built-in wireless transceiver to enable a wireless room thermostat, maintaining the traditional layout of separate time control and room thermostat. It can also be used on new systems. Because the room thermostat and the timer communicate, energy-saving and operating benefits are also enabled.

• Energy saving time proportional and integral (TPI) control
• Wireless enabled upgrade
• Two way wireless communication
• Wireless signal strength indicator
• Built in economy or comfort programmes on ST9120C
• LoT display for easy programming on ST9120C
• ST9120C fits on industry standard backplate
• ST9120C is a direct replacement for ST9100 and ST6100 models
• ECO setback function on DT92E
• Frost protection on DT92E