The NIBE Low Pressure Switch (Part No. 718137) is a safety component used primarily in classic NIBE Fighter series ground-source heat pumps.

Key Technical Specifications

• Operating Pressure Range: 0.8 to 1.5 Bar

• Function: Monitors low-side refrigerant pressure. If pressure drops below 0.8 bar (often due to a refrigerant leak, extremely low source temperature, or a fan/brine flow failure), it cuts power to the compressor to prevent mechanical burnout or freezing damage.

Primary Model Compatibility

Used in NIBE’s commercial and high-capacity ground source heat pumps, most notably:

• NIBE F1345 Series (e.g., F1345-24 kW / F1345-30 kW and related commercial variants)

You typically need to replace or test this component if: 

1. The heat pump’s display shows a persistent Low Pressure Alarm / Defrost Fault even when refrigerant charge and brine/air flow are completely normal.

2. The internal microswitch has failed open, preventing the controller from starting the compressor.