The Honeywell Home V4073A1088/U 28 mm Mid‑Position Mid‑Position Valve is a robust 28 mm motorised 3‑port valve built to manage flow in domestic central heating systems where both the radiator and hot‑water cylinder circuits are pumped. With compression connections, spring‑return action, manual lever for filling/draining and removable power‑head without system drain‑down, it’s designed to simplify installation and improve system performance.