Heating pump controller TECH ST-21, anti-stop, antifreeze, thermostat function, black

TECH ST-21 is a heating pump controller designed for central heating systems. The device integrates anti-stop and antifreeze functions and can operate as a thermostat to switch the pump on or off based on measured temperature. Finished in black, the controller is intended for reliable management of circulating pumps in residential and small commercial heating installations, helping to prevent pipe freezing and reduce the risk of pump seizure during infrequent operation.

Advantages

The controller combines temperature-controlled switching with an anti-stop routine that periodically activates the pump to avoid mechanical seizing after long idle periods. An antifreeze function monitors ambient temperature and starts the pump when temperatures approach freezing, protecting pipework. The compact black housing allows easy installation in typical boiler rooms or pump cabinets and the straightforward thermostat operation simplifies configuration and daily use.

Suitable for

• Circulating pumps in residential central heating systems
• Small commercial or utility heating circuits
• Seasonal properties or rarely used systems that need anti-freeze protection
• Situations where periodic anti-stop activation is required to maintain pump operability

Key specifications

• Functions: temperature thermostat control, anti-stop periodic activation, antifreeze protection
• Control principle: switch based on measured ambient or system temperature
• Housing: compact form factor in black finish suitable for indoor installation
• Intended application: management of circulating heating pumps in small to medium systems

How to use

Mount the TECH ST-21 in a dry, accessible location close to the pump or in the boiler/pump cabinet according to local electrical rules. Connect the controller to the pump power circuit and to any required temperature sensor or local temperature point following the installation manual and national wiring regulations. Set the desired temperature threshold and, if available, configure the anti-stop intervals so the pump is periodically activated during long idle periods. Verify correct operation by observing pump switching in response to temperature changes and the anti-stop routine.

Usage recommendations

For reliable performance, install the controller in a frost-free location away from direct heat sources and moisture. Ensure electrical connections are made by a qualified electrician and check periodic operation during seasonal transitions. Regularly inspect the pump and controller for signs of wear or corrosion and follow manufacturer guidance for maintenance.