Stiebel Eltron part number 326394 is an official OEM Expansion Valve Assembly used in several Stiebel Eltron heat‑pump systems. 

Details
•     Component type: Expansion Valve Assembly
•     Manufacturer: Stiebel Eltron
•     Part number: 326394
•     Function: Regulates refrigerant flow in the heat‑pump circuit to maintain correct operating pressures and temperatures.

Compatible 
•     WPL 17 ACS Classic
•     WPL 07 & 09 ACS Classic

Part Details
•     OEM Stiebel Eltron replacement part
•     Category: Compressor & F‑gas components
•     Typical dimensions listed: 40 × 16 × 13 mm
•     Suitable for authorised installer replacement only.