Industrial-Grade Build: Features a rugged zinc die-cast housing that protects internal components from debris and environmental stress

Always verify the incoming terminal voltage before installation to prevent burnout from improper electrical characteristics

this outdoor temperature sensor is the likely culprit

This unit is built with sleeve bearings and a totally enclosed non-ventilated (TENV) enclosure

It must be paired with the 6003 gas valve and is not compatible with Robertshaw components

Lochinvar & A.O. Smith 100093811 Door Switch 319847-401 Industrial-Grade Build: Features a ruggedWhen you're troubleshooting a natural gas water heater that won't ignite or is throwing intermittent error codes, the Lochinvar & A. O. Smith 100093811 Door Switch is a critical safety component to inspect. Designed specifically for the NAT FG40T40 series, this OEM replacement door switch serves as a definitive safety interlock, ensuring the burner assembly is correctly isolated and the access door is fully secured before allowing the ignition