Modine SPST Pressure Switch WC

The Modine SPST pressure switch is a genuine Modine replacement part for gas-fired unit heaters. It is a single-pole, single-throw (SPST) switch that senses air pressure. Depending on the heater, it may be called a vent pressure switch, combustion air proving switch, or blocked vent switch. Each model in this line has its own pressure setting, which is rated in inches of water column ("WC).

Key Features:

• SPST switch design: single-pole, single-throw contacts that open or close in response to pressure.
• Pressure-sensing safety control: Modine's automatic reset vent pressure switch is designed to stop the main burner from running if flue products can't vent properly.
• Rated in inches of water column: each model has its own calibrated switching point, so it suits the heater it was designed for.
• OEM Modine part: made to Modine specifications for heater controls.

Restricted venting can come from an improper vent diameter, long vent runs, an unapproved vent terminal, high winds, or high negative pressure in the space. The switch is intended to help keep the heater from running in those conditions. Check that you are ordering the model with the correct water column rating for your heater.