Radiator Thermostat DANFOSS RTW-K 8–28 °C mechanical (MPN 013G6505)

The mechanical radiator thermostat DANFOSS RTW-K 8–28 °C is a manually operated valve head designed to regulate room temperature by controlling the flow of hot water through radiator valves. The unit provides a simple and reliable way to maintain temperatures between 8 and 28 °C without the need for electricity or electronic control. Constructed for direct mounting on standard radiator valves, the RTW-K offers intuitive rotary adjustment and a visible temperature scale for straightforward operation in residential and light commercial heating systems.

Advantages

The DANFOSS RTW-K thermostat delivers stable temperature control using a robust mechanical sensing element that responds directly to ambient room temperature. Its operation is independent of power supply and electronics, which reduces installation complexity and long-term maintenance. The compact design and clearly marked temperature range make it easy to set desired comfort levels and avoid overheating. Durable materials and a straightforward mechanical mechanism contribute to long service life and predictable performance.

Suitable for

• Individual room temperature control on panel radiators
• Retrofit replacement of existing mechanical thermostat heads
• Residential apartments, houses and small commercial spaces
• Basic zoned heating setups without electronic thermostatic control

Key specifications

• Adjustment range: 8–28 °C
• Type: mechanical, manually operated thermostatic head
• Mounting: direct fit to standard radiator valve bodies
• Control method: rotary knob with marked temperature positions
• Power: no external power or batteries required
• Intended application: hot-water radiator heating systems

How to use

Attach the RTW-K thermostat head directly to a compatible radiator valve according to the valve manufacturer’s mounting instructions. Once mounted, rotate the control knob to align the indicator with the desired temperature mark within the 8–28 °C scale. The mechanical element inside the head senses room temperature and modulates the valve position to maintain the setpoint. Periodically check the mounting and clean the exterior to ensure the sensing element is not obstructed by curtains, furniture or dust.

Usage recommendations

For accurate room regulation, install the thermostat head on a radiator where airflow is not blocked and away from direct sunlight, drafts or heat sources. When replacing an existing head, confirm compatibility with the valve spindle and follow safe isolation of the heating system if required. Use the RTW-K in conjunction with a sensible heating schedule to reduce energy waste and avoid setting overly high temperatures that can lead to overheating.