The Siemens 243-0018 is a non-adjustable logic relay

This HVAC compressor cooling solution ensures your 4D series semi-hermetic compressor stays within its safe operating envelope during high-compression ratio cycles

Operating at a 1755 RPM base speed

an open circuit or infinite resistance indicates a failed thermistor element

While designed for differential velocity pressure

Lochinvar & A.O. Smith 100110220 Gas Valve 340793-762 The Siemens 243-0018 is aThe Lochinvar & A. O. Smith 100110220 Gas Valve is a critical replacement component designed for high efficiency water heaters and boilers, including many models in the Lochinvar Copper Fin II and Knight series. This 1 inch NPT natural gas valve operates on a 24V control circuit and is factory set to a 3. 5" water column (WC) outlet pressure, ensuring the precise fuel to air mixture required for clean combustion. As a direct replacement for part