Central heating timers

Advice on how to use heating controls.

A combination boiler only heats up water when you turn on a hot tap, so you don’t need to programme it. If you have a hot water cylinder however, the water in the cylinder will need to be heated up during the course of the day.

In most cases the functions on your programmer are:

  • Auto’ or ‘Twice’ means the heating goes on and off during the day at the times it has been programmed to do so
  • ‘24hrs’ or ‘On’ means the heating stays on all the time
  • ‘Off’ means the heating will remain off all the time
  • ‘All day’ or ‘Once’, means the heating will switch on at the first ‘on’ setting you have programmed and then remain on until the last ‘off’ setting of the day
  • ‘Boost’ or ‘+1hr’ switches the heating on for a one hour ‘boost’ of heat
  • ‘Advance’ moves the programmer to the next ‘on’ or ‘off’ setting in the daily cycle

For more information on your particular programmer see the links below:

This is a 24 hour time switch with four switching options, along with:

  • Boost & advance
  • Holiday mode
  • Automatic summer/winter time change
  • Built-in standard programme - 3 on/off settings

Download User instructions


 The Horstmann CentaurPlus C17 timeswitch will allow:

  • up to 3 ON/OFF settings per day for each day of the week
  • has a 1 hour manual boost
  • advance button to temporarily override current settings
  • a programming switch allowing permanent selection of OFF/ON/AUTO/ALL DAY.

Download user instructions

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