Ma-Ter Pressure switch DR2 DR7AB1AA080290

This pressure switch from Ma-Ter, model DR2, is a safety device for burner and boiler systems, with a designation that includes 800 mbar. It confirms that pressure or airflow is within the permitted band and gives the burner control permission to continue operation. This item can serve as an air or gas pressure switch.

When selecting a replacement pressure switch of this kind, match the medium (air or gas), switching range and differential, connection thread or hose spigot, contact rating, and applicable approval class. During installation, verify that the impulse line is clear and correctly routed, and that the pressure tapping point is in a region of stable pressure. Adjust the setpoint with a manometer to the value required by the burner specification, and ensure the electrical contacts are rated for the control voltage and current.

Typical failure modes include a torn diaphragm, a blocked impulse tube, or a drifted setpoint. These faults cause lockouts that are often mistaken for ignition problems. Check that the impulse line is clear and correctly routed, and confirm the setpoint with a manometer.