TPI (Time Proportional & Integral) control is an industry standard term for an On/Off control using an advanced energy saving control method that can be used by most heating systems in the UK. The controls simply switch current supplied to the boiler on or off at different times. Unlike a traditional thermostat, these rely on digital technology that matches the boiler firing to theload on the system.

The DT90E digital room thermostat has been designed to provide automatic temperature control of gas or oil fired boiler systems, underfloor heating, electric heating and zoning systems.   The DT90E has an ECO button energy saving feature which gives timed setback or boosts temperatures to reduce energy...
See how easy it is to fit a Sundial RF² Pack 1!     Sundial RF² Pack 1 (Y9120H2009) contains:   Wireless enabled timeswitch (ST9120C) Wireless room thermostat (DT92E) Ideal for adding a room thermostat to a combi boiler or an individual heating...
Sundial RF2 Pack 4 (Y9120W1000) contains:   ST9120C Wireless Timer CS92A Wireless Cylinder Thermostat   Ideal for adding a hot water timer and cylinder thermostat to new and existing Sundial systems, or upgrading a gravity hot water system.   Features Energy saving TPI (Time Proportional...
See how easy it is to fit a Sundial RF² Pack 2!     Sundial RF² Pack 2 (Y9420H1008) contains:   Wireless enabled programmer (ST9420C) Wireless room thermostat (DT92E) Ideal for adding a room thermostat to a traditional system.     Features Energy saving...
See how easy it is to fit a Sundial RF² Pack 3!     Sundial RF² Pack 3 (Y9420S2005) contains:   Wireless enabled programmer (ST9420C) Wireless room thermostat (DT92E) Wireless cylinder thermostat (CS92A) Ideal for adding a room thermostat and a cylinder thermostat to...
The DT92E wireless digital room thermostat has been designed to provide automatic temperature control of gas or oil fired boiler systems, underfloor heating, electric heating and zoning systems.   The DT92E has an ECO button energy saving feature which gives timed setback or boosts temperatures to reduce...
The Y6630D is a battery powered Wireless Room Thermostat and mains powered HC60NG Receiver Box, pre-bound to give intelligent room temperature control of a single zone. It can be used in conjunction with the Sundial Y or S Plan or as a stand alone device for room temperature control of a combi boiler system. The...