Feb 25, 2025
A Capillary Thermostat in an underfloor heating system works by regulating the floor temperature to ensure comfort and energy efficiency. It operates using a liquid-filled sensing bulb and a capillary tube, which detects temperature changes and controls the heating circuit accordingly. Here's how it functions in detail:
Temperature Sensing
The capillary thermostat consists of a sensing bulb filled with an expanding liquid (such as gas or fluid).
This bulb is placed within the heated floor or near the heating element to monitor the floor temperature.
Thermal Expansion & Activation
As the floor temperature increases, the liquid inside the bulb expands, creating pressure within the capillary tube.
The pressure acts on a diaphragm or bellows, which triggers a mechanical switch.
Controlling the Heating Element
When the floor reaches the preset temperature, the thermostat switch opens to cut off the power supply, stopping the heating.
If the temperature drops below the set point, the liquid contracts, the switch closes, and the heater turns back on.
Precise Temperature Control – Ensures floor temperature does not exceed comfortable levels.
Energy Efficiency – Prevents overheating, reducing energy consumption.
Simple and Reliable – Mechanical operation without the need for complex electronic controls.
Wide Temperature Range – Can be adjusted to suit different flooring materials (tile, wood, laminate, etc.).
Failsafe Mechanism – Provides overheat protection, preventing floor damage and improving system longevity.
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