Hydrotherm BM-8785 Rollout Switch

The Hydrotherm BM-8785 Rollout Switch is a critical safety component engineered for high-temperature thermal protection in industrial and commercial heating systems. Designed as a 350F M/R rollout switch, this device monitors combustion chambers and heat exchangers for dangerous flame rollout conditions. When temperatures exceed the 350°F threshold, the precision snap-action mechanism interrupts the electrical circuit, requiring a manual reset to restore operation after the fault is cleared. This specific HVAC rollout limit switch features a robust corrosion-resistant steel enclosure, making it suitable for high-cycling applications and harsh environments often found in boilers, furnaces, and ovens.

For technicians and contractors, the BM-8785 provides a reliable 15A at 120VAC contact rating, ensuring seamless Hydrotherm boiler part compatibility and integration into existing control circuits. Its durable construction minimizes nuisance failures while maintaining strict adherence to safety protocols during high-demand operation.

Key Benefits

• Precision Thermal Sensing: Designed to trigger at exactly 350°F to prevent heat exchanger damage and hazardous rollout.
• Manual Reset Capability: Ensures professional inspection of the heating appliance before the system can be restarted.
• Robust Build Quality: Features a steel housing with a corrosion-resistant finish for long-term performance in industrial settings.
• High Electrical Rating: 15A @ 120VAC rating supports integration into standard commercial HVAC control loops.

Common Questions

Can this switch be used as an automatic reset limit?
No, the BM-8785 is a manual reset (M/R) device. This is a safety requirement for rollout applications, ensuring a technician identifies why the flame migrated before the unit resumes operation.

What causes a 350 degree rollout switch to trip?
Tripping is typically caused by a cracked heat exchanger, soot buildup, or improper venting, which forces the flame or hot gases out of the combustion chamber.

Is this compatible with non-Hydrotherm units?
While designed for Hydrotherm systems, it can function in other heating appliances requiring a 350°F manual reset rollout protection, provided the mounting and electrical ratings match the original specification.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.