The Honeywell V4073A1039 Mid‑Position Valve is a 22 mm compression three‑port motorised valve designed for conventional pumped central‑heating systems. It features a manual lever for filling/down‑filling, spring‑return operation, and a replaceable powerhead without system drainage, making it a reliable choice for installers seeking efficient flow‑diversion in Y‑Plan or S‑Plan configurations.