Weil McLain 512 200 055 Burner This SPDT Relay is commonly This SPDT Relay is commonly utilized for fan speed switching or as an isolation relay for low voltage thermostats to protect circuit boards from higher amperage draws The System Sensor 5621 is a commercial grade dual circuit mechanical heat detector designed for high reliability fire detection in environments where traditional smoke sensors are prone to nuisance alarms Replacing with a tubular steel burner restores the correct venturi action for a clean burn The Weil McLain 512 200 055 Burner is a precision engineered tubular steel burner specifically configured with an integrated pilot bracket to ensure stable ignition and consistent flame patterns across the heat exchanger