You must always use the HH18HA493 if that is the specified Carrier replacement part for your unit

8 bar) and is compatible with modern refrigerants

This module is designed to accept a nominal 24VAC input

and potable water supply lines

the SP11700 thermostat features a single-pole (SPST) high-limit control with a 170°F safety cutoff and a manual reset button to prevent hazardous overheating conditions

Heil Quaker ICP 1110752 Fan Control Els PW 17895 You must always use theThis Heil Quaker ICP 1110752 Fan Control is a critical electronic component engineered for HVAC fan motor regulation within International Comfort Products (ICP) systems. Designed as a direct replacement part, this fan control board manages airflow management by modulating fan speeds based on real time system demands. For service technicians, this board is essential for resolving furnace blower motor cycling issues or intermittent operational failures