McDonnell & Miller 304400 Cover for DC applications

for DC applications

Contractor-Grade Reliability: An essential Watts replacement part that meets original equipment manufacturer (OEM) standards for long-term field performance

but it is typically utilized in series with the 24V gas valve or contactor coil circuit

Industrial-Grade Built: High-quality materials resist housing cracks and contact pitting for consistent electrical performance

the switch is calibrated to open at 150°F to prevent heat exchanger damage and close at 120°F once safe operating temperatures are restored

McDonnell & Miller 304400 Cover for DC applicationsThe McDonnell & Miller 304400 is a genuine replacement flow switch cover (Model FS4 3COV) engineered specifically for Xylem FS4 3 liquid flow switches and the AF 1, AF 2, and AF 3 airflow switch series. In demanding commercial boiler and process piping environments, maintaining the integrity of the switch housing is critical for protecting the single pole, double throw (SPDT) snap switch and internal sensitivity adjustments from dust, moisture, and