ThermoPlus PRT 1 is a programmable thermostat for controlling the temperature and schedule of central heating.  It provides up to 6 different temperatures and associated on/off periods that are applied consistently every day of the week.

ThermoPlus PRT 1 is battery powered and can directly replace an existing thermostat, programmer or both.  It can also be used for timed control of temperature for an additional zone.

ThermoPlus PRT 1 works with most domestic gas, solid fuel and oil-fired central heating and hot water systems.



  • Replacement of single-channel central heating programmer and thermostat

    Thermoplus PRT1 will replace both an existing single-channel programmer and a thermostat with a single, compact unit.  It will provide 6 daily controlled temperature periods, applied every day.

    Single device for central heating control in new builds

    Thermoplus PRT1 is ideal for use in new builds of up to 150 m2 floor area, where a combi boiler is installed with a single zone. One device can control the temperature and boiler scheduling, via a single connection.

    Improve boiler economy by replacing a single-channel programmer

    Thermoplus PRT1 can replace an existing single-channel programmer without a thermostat, to provide scheduled temperature control, together with improved economy through the use of TPI technology.

    Replace a thermostat-only system

    Thermoplus PRT1 can replace an existing thermostat-only system and provide up to 6 timed temperature values per day, combining the flexibility of a programmer with the efficiency of a TPI thermostat.

  • Key Feature

    • Single-channel programmable thermostat
      • Replaces an existing thermostat, with no need to connect to mains power (battery powered)
      • Replaces existing thermostat and/or programmer with a single device
      • For new builds with combi boilers, single zone2floor area (2 units can be used for larger areas)
      • Provides greater efficiency through time proportional integral (TPI) boiler control
    • 24-hour temperature time profiles
      • 24-hour programme operates every day of the week
      • Up to 6 scheduled periods and temperatures per day
    • Simple user operation, with visual indication
      • Choice of display options for monitoring time and temperature settings
      • Override by ‘Plus’ and ‘Minus’ buttons for immediate and direct control of temperature
    • Specification
    • Customer testimonials
    • Electrical

      Power supply

      3x AA alkaline batteries

      Contact type

      Micro-disconnection changeover

      Wiring configuration

      Volt-free powered c/o contacts (SPDT) no/nc

      Contact rating

      8 (3) A, 230 V, 50 Hz

      Battery life

      In excess of 2 years


      Double insulated

      Power supply

      3x AA alkaline batteries


      Pollution degree


      Enclosure protection


      Operating temperature range

      0 °C to +40 °C

      Technology features


      Target temperature indication, with 12 hour AM/PM clock or actual temperature

      Control technology








      Systems compatibility

      Gravity or fully pumped

      Boiler types

      Gas, oil, electric (via contactor for > 8 A), combi

      User interface


      24 hours, where each day has the same ON/OFF times

      Number of periods/temperatures per day

      6 per 24 hours (same each day)

      Temperature setting range

      +5 °C to +30 °C


      Advance to next programme (ON or OFF)

      Switched time adjustments

      10-minute steps

      Override features

      (AUTO / ALL DAY/ 24 HRS/ OFF)



      12 hour, with AM/PM

      TPI temperature differential


      Temperature measurement Accuracy at 20 °C

      -0.25 °C/+0.75 °C for wet central heating


      Dimensions (W x H x D)

      142 mm x 71 mm x 30 mm


      Directly on to a wall, or into a single or double-gang steel flush wiring box to BS4662, via a pattress (available on request)

    • Testimonial-01 dated 6th Jan 2016✰✰✰✰✰

      Excellent value thermostat

      6 Jan 2016

      By sortitmyself

      , Bolton, Lancs

      " Hadn't realised my old thermostat was failing so badly until I replaced it with this unit. After investigating most of the system I worked out it had to be a new thermostat. This unit fits over a standard junction box, but only just. The instructions give a phone no to obtain a mounting pattress so that the edges of the back box are obscured, didn't try this as old thermostat was much larger so have mounted on a plywood panel until I re-decorate. The unit is very easy to install, set up and also looks good in an older house. I particularly like the display of actual and target temperature - we've enough clocks in the house. "

      Testimonial-02, dated 6th Jan 2016 ✰✰✰✰✰

      6 Jan 2016

      By MusicRab

      , Farnham

      " Needed a replacement thermostat for a failed/ancient thermostat (external to Baxi Combi 105e). A programmable one was needed to avoid getting on knees to tweak the current-on-boiler-timings. Old control has 3 wires :- Live (wire1), Heating Load (2) and Neutral ("accelerator heater" whatever that is) (4). These mapped onto same numbered terminals on the Horstmann (more by luck than judgement I guess). Had to provide my own mounting screws for backplate. Removal of backplate from main unit was hard work (there's a side release button) but managed it in the end. Works no problem. Have to program unit next. I hope the batteries last a while...5* price, product and Screwfix. (**remember to isolate mains before performing work.**) "

      Testimonial-03, dated 31st Oct, 2015 ✰✰✰✰✰

      31 Oct 2015

      By mhin

      , London

      " My Worcester 24i timer was broken/failing. Bought this to by-pass timer. Thought wiring would be complicated but replaced my Honeywell thermostat with the centaur 7 easily...actually same two wired system.

      The programming was simpler than thought. "