it will not generate the vacuum needed to close the pressure switch

If 24V is present but the contacts do not pull in

Whether you are retrofitting an older mechanical room or servicing an existing I/A Series pneumatic loop

For contractors managing HVAC gas valve troubleshooting

Lochinvar & A.O. Smith 100271315 Limit Switch 30067439-890 it will not generate theThe Lochinvar & A. O. Smith 100271315 Limit Switch is a critical safety component engineered for high performance hydronic and water heating systems. As a veteran technician knows, maintaining the integrity of the safety loop is non negotiable. This OEM high limit switch is designed to monitor outlet water temperature and provide a positive safety shutdown by interrupting the electrical circuit if temperatures exceed the factory set threshold,