Kromschroder Air pressure switch DL 5K-3W 84444700

The Kromschroder DL 5K-3W air pressure switch (SKU 84444700) is a German-made device designed to monitor air and non-combustible gas pressure in ventilation, air conditioning, heating, and air exchange systems. It operates within a pressure range of 0.4 to 5 mbar, detecting positive, negative, or differential pressure. When the pressure deviates from the set point, the switch automatically opens or closes electrical contacts to prevent equipment malfunction. The switch features manual adjustment via a built-in hand wheel and electrical connection through screw terminals.

When selecting a replacement air pressure switch of this kind, verify that the adjustable pressure range covers the required set point and that the electrical rating matches the burner control's input. Check the connection type (thread or hose spigot) and physical dimensions to ensure compatibility with existing mounting. Confirm the impulse line is clear and correctly routed before installation.

Failures in air pressure switches of this kind often manifest as repeated burner lockouts that mimic ignition faults. Common causes include a torn diaphragm, a blocked impulse tube, or drift in the setpoint. Check the diaphragm, impulse line, and setpoint calibration when such symptoms occur.