It will automatically re-engage the circuit once the sensed temperature falls back within the safe operating range

What is the difference between this and a normally closed valve in a power failure

The most common signs are repeated ignition failures (Lockout)

Engineered with a 1/2" NPT standard shank

Hydrotherm BM-8073 Pilot Assembly 320788-702 It will automatically re-engage theThe Hydrotherm BM 8073 Pilot Assembly is a critical OEM replacement component engineered specifically for liquid propane (LP) boiler systems. As a veteran grade standing pilot assembly, the BM 8073 ensures consistent ignition and flame monitoring for Hydrotherm gas fired units. This robust assembly features the LP Q314ALB pilot burner configuration, designed to provide a stable, high efficiency pilot flame for reliable main burner ignition. When