DIFF Pressure Switch

DIFF brand mechanical pressure switch. Cuts the heating element when internal boiler steam pressure exceeds threshold; restarts when pressure drops below — core control of the thermal cycle. Standard on KL-01..04 and KM-02..08. Premium Danfoss alternative ($45) kept in service stock; DIFF $5 is the economical day-to-day option. Test every 6 months; replace immediately if stuck, cracked, or out of calibration.