Thermal protection for boiler Watts Italia STS 20 with 130 cm capillary (model 0232120)

The Watts Italia STS 20 thermal protection with a 130 cm capillary is a temperature safety device engineered for domestic and commercial boilers. It monitors water or system temperature and triggers an automatic safety shutdown when preset limits are exceeded, reducing the risk of damage to heat exchangers, pumps and other boiler components. The unit is suitable for integration into existing boiler control arrangements where an overtemperature cut-out is required.

Advantages

This thermal protection device offers precise temperature sensing through its capillary probe, reliable automatic interruption of boiler operation at excessive temperatures and compact construction for straightforward installation. Its design focuses on dependable operation in fault conditions, helping to safeguard critical hydraulic and heat transfer components without requiring complex wiring or controls.

Suitable for

• Domestic central heating boilers
• Commercial small-scale heating systems
• Protection of heat exchangers and circulation pumps
• Retrofit safety upgrades and maintenance replacements

Key specifications

• Function: overtemperature cut-out / thermal safety switch
• Capillary probe length: 130 cm
• Application: boiler temperature monitoring and automatic shutdown
• Mounting: panel or boiler body integration with probe placement in thermal mass or sensor pocket
• Electrical interface: single-function safety output compatible with standard boiler control circuits

How to use

Install the capillary probe in the boiler’s designated sensor pocket or securely fasten it to the heat exchanger or pipework where representative temperature measurement is achieved. Connect the device to the boiler control wiring following the boiler manufacturer’s wiring diagram and ensuring power is isolated during installation. Set or confirm the operating threshold according to system requirements and test the safety cut-out by simulating an overtemperature condition or following the commissioning procedure specified by the boiler maker.

Usage recommendations

Position the capillary probe where it measures the medium temperature most accurately and avoid tight bends that can damage the capillary. Verify electrical connections and insulation regularly, and include this thermal protection in routine boiler maintenance checks to ensure reliable operation during fault conditions.