The B240 series provides a close-off pressure of 200 psi

Rated for a maximum working pressure of 125 PSI

meaning it completes the 24V circuit only when the required vacuum threshold is reached

It utilizes a 24V bimetal heater disc to activate high-voltage contacts

The 137000 includes a quick-change replaceable cartridge valve and strainer

Williams 9940 Converter 321702-401 The B240 series provides aThe Williams 9940 Hard Wire Converter is a critical component for integrating modern electronic thermostats with older 24V furnace systems that lack a dedicated C wire. This HVAC power interface converts 115V line voltage into the 24V supply necessary to power digital controls, ensuring stable operation without battery drain. Designed specifically for compatibility with Williams furnace models and wall heaters, this 10VA rated converter facilitates a