Since safety circuits in modern HVAC systems rely on precise resistance and thermal response

keeping the system running at peak efficiency

The ZoneFirst PIRR is a 24Vac 4PDT Plug-In Relay engineered as a direct high-performance replacement for RR and RMABS relays

protecting the new components

York S1-024-18785-700 Control Relay Since safety circuits in modernThe York S1 024 18785 700 Control Relay is an OEM replacement part designed for precise electrical circuit management in commercial and residential HVAC systems. Functioning as a heavy duty electromechanical switch, this 24V service relay is engineered to interface between low voltage control circuits and high voltage load components. This allows for the reliable activation of motors, compressors, and heating elements while isolating sensitive control