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 demand. This is a TPI (Time Proportional Integral) control product, which make boilers operate more efficiently and provide close accurate control. The 'OFF' setting can be used for frost or hypothermia protection, assuming the system time control is also switched on.