Honeywell Sundial RF2 Pack 3 Y9420S2005

Item code
Lead time
1-2 working days
Delivery cost
Honeywell Sundial RF2 Pack 3 Y9420S2005


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£216.66 Excl VAT £259.99 Inc VAT

Product details

The Honeywell Sundial RF2 Pack 3 (Y9420S2005) contains:

  • Wireless enabled programmer (ST9420C)
  • Wireless room thermostat (DT92E)
  • Wireless cylinder thermostat (CS92A)

This pack is ideal for adding a room thermostat and a cylinder thermostat to a traditional system.

In a stored hot water heating system which has no room thermostat or cylinder thermostat the existing wiring can be used to provide Boiler Interlock by fitting Sundial RF2 Pack 3. This has a full programmer, with independent heating and hot water and a built in wireless transceiver to enable the wireless room thermostat and cylinder thermostat, maintaining the traditional layout of separate time control and thermostats. It can also be used on new systems. Because the thermostats and the programmer communicate, energy saving and operating benefits are also enabled:

Programmer override from the thermostat.

Cylinder thermostat controlled from the programmer.

†TPI control: Time Proportional and Integral (TPI) control is a method of calculating the demand from a room thermostat, controlling the boiler so that it fires for shorter periods as the temperature approaches the set point. This can offer savings of up to 10% of energy consumption (in a single cycle steady state test).

*Optimum Start: To save energy, let the controls work out when to come on to suit when you want to be warm. Every day the boiler will start at the latest possible moment depending on the weather.

**Delayed Start: Once you have programmed your earliest start time, the controls will delay the boiler firing time on warmer days, when it is possible to save energy.

***Optimum Stop: Saves energy and money by switching off before the normal programme time whenever possible.

Sundial RF2 Pack 3Features:

  • Energy saving TPI control (see FAQ TPI Control)
  • Wireless enabled upgrade
  • Two way wireless communication
  • Wireless signal strength indicator
  • Built in Economy or Comfort programmes on ST9420C
  • LoT display for easy programming on ST9420C
  • ST9420C fits on industry standard backplate
  • ST9420C is a direct replacement for ST9400 and ST6400 models
  • ECO setback function on DT92E
  • Frost protection on DT92E
  • Tabletop stand supplied for DT92E
  • CS92A set and controlled from programmer
  • DT92E and CS92A both battery powered - no wiring.


Show VAT?

£216.66 Excl VAT £259.99 Inc VAT


  • Lead Time
    1-2 working days
  • Type
    Heating Control Pack
  • Wireless
  • Interface
  • Channels
  • Program Options
    7 Day
  • Manufacturer Part No:
  • GTIN