The new DT90 family of digital room thermostats is a range of market leading products designed to provide comfort with economy in modern heating systems. Its large display and simple button interface make DT90 extremely easy to use. Energy efficiency is addressed by state-of-the-art TPI control performance and an ECO button energy saving feature. Applications include control of gas or oil-fired boiler systems, underfloor heating, electric heating and zoning systems. With a modern fresh look that complements any style of décor, and a range of valued features for users and installers alike, DT90 sets the standard for simple environmentally-friendly room thermostats.
The DT90 digital room thermostat offers a large high‑contrast display, simple button interface, and energy‑saving TPI control with an optional ECO button. It is battery powered (2 × AA cells) and suitable for gas, oil, electric, or under‑floor heating systems, as well as cooling applications.
The manual covers installation guidelines, wiring diagrams, and the Installer Mode where parameters such as minimum on/off time, cycle rate, proportional band, and setpoint limits can be configured. It also explains the off/standby function with frost protection and the ECO energy‑saving feature.
| Power supply | 2 × 1.5 V AA alkaline cells |
|---|---|
| Battery life | Typically 4 years, minimum 2 years |
| Setpoint range | 5 °C to 35 °C in 0.5 °C steps |
| Electrical rating | 230 V 50‑60 Hz, 0.01 A‑8 A resistive, 0.1 A‑3 A inductive |
| Switch type | SPDT potential‑free |
| Dimensions (unit) | 90 × 92 × 27 mm |
| Weight (unit) | 165 g |
| IP class | IP30 |
| Storage temperature range | -20 °C to 55 °C |
| Humidity range | 10 % to 90 % RH non‑condensing |
| Relay life | ≥ 100 000 operations |
| Proportional band | 1.5 °C to 3 °C |
| Minimum on/off time | 1‑5 minutes |
| Cycle rate | 3, 6, 9, or 12 cycles per hour |
Press the up or down buttons (labeled A and ¥) to increase or decrease the setpoint in 0.5 °C steps.
The thermostat is powered by two AA alkaline cells and typically lasts up to four years, with a minimum of two years before a low‑battery warning appears.
It switches the heating or cooling system off and activates frost protection at a default setpoint of 5 °C, which can be adjusted between 5 °C and 16 °C.
The ECO button lowers the setpoint for a user‑selected period (1‑24 hours) and shows a countdown timer while in energy‑saving mode.