{"product_id":"honeywell-home-40003916-003-u-replacement-actuator-powerhead-v4073a-3-port-mid-position-5-wire-motorised-valve","title":"Honeywell Home 40003916-003\/U Replacement Actuator Powerhead V4073A 3-Port Mid-Position 5-Wire Motorised Valve","description":"\u003cdiv style=\"font-size:16px;font-family:Arial,Helvetica,sans-serif;color:#1a1a1a;max-width:900px;margin:0 auto;line-height:1.6;\"\u003e\n\n  \u003c!-- ── INTRO ─────────────────────────────────────────────────────── --\u003e\n  \u003cp style=\"margin:0 0 18px;\"\u003e\n    The \u003cstrong\u003eHoneywell Home 40003916-003\/U\u003c\/strong\u003e is the genuine replacement powerhead (actuator assembly) for \u003cstrong\u003eHoneywell V4073A 3-port mid-position motorised valves\u003c\/strong\u003e — the standard 5-wire valve used in Y-plan central heating systems across the UK. When a V4073A head develops a fault — humming motor, stuck mid-position, failure to open or close, seized manual lever — this powerhead replaces the entire electrical and mechanical assembly \u003cstrong\u003ewithout removing the valve body from the pipework and without draining the system\u003c\/strong\u003e (on post-1987 valves). Fitting requires only \u003cstrong\u003etwo screws and two locating pegs\u003c\/strong\u003e, takes around 30 minutes, and avoids the disruption and cost of a full valve replacement. Compatible with V4073A1039, V4073A1054, V4073A1062, and V4073A1088. \u003cstrong\u003e230V ~ 50Hz · 6W · 1m lead supplied\u003c\/strong\u003e. Spring-return operation. Maximum static pressure \u003cstrong\u003e8.6 bar\u003c\/strong\u003e. GTIN 5023220401476. \u003cstrong\u003e1-year manufacturer's warranty\u003c\/strong\u003e (Honeywell Home by Resideo).\n  \u003c\/p\u003e\n\n  \u003c!-- ── AMBER PRE-1987 CALLOUT ────────────────────────────────────── --\u003e\n  \u003cdiv style=\"border-left:4px solid #e67e22;background:#fef9f0;padding:10px 16px;margin-bottom:14px;border-radius:0 6px 6px 0;\"\u003e\n    \u003cstrong style=\"color:#b7580a;\"\u003e⚠ Pre-1987 Valves Require an Additional Adaptor Kit — How to Check\u003c\/strong\u003e\u003cbr\u003e\n    V4073A valves made \u003cstrong\u003eafter 1987\u003c\/strong\u003e can accept this powerhead directly, without draining — identified by a \u003cstrong\u003esmall circular bump on the top cover\u003c\/strong\u003e of the existing head and an OS suffix number of \"6\" or higher. Valves made \u003cstrong\u003ebefore 1987\u003c\/strong\u003e have a flat cover with no bump and use four screws (not two) to secure the head — these require the \u003cstrong\u003e40003918-007 adaptor kit\u003c\/strong\u003e (sold separately) before the 40003916-003 can be fitted. Fitting the new head to an old-style body without the adaptor kit will result in an insecure connection and potential water leakage. If in doubt, count the screws on the existing head: two screws = new style (no adaptor needed); four screws = old style (adaptor required).\n  \u003c\/div\u003e\n\n  \u003c!-- ── RED INSTALLER CALLOUT ─────────────────────────────────────── --\u003e\n  \u003cdiv style=\"border-left:4px solid #c0392b;background:#fff5f5;padding:10px 16px;margin-bottom:22px;border-radius:0 6px 6px 0;\"\u003e\n    \u003cstrong style=\"color:#c0392b;\"\u003e⚠ Isolate Power Before Work — Qualified Electrician for Rewiring\u003c\/strong\u003e — Switch off all power supplies to the heating system before removing the existing head. Carefully note the position and colour of each existing wire before disconnecting. The wiring diagram in the installation instructions must be followed precisely — incorrect connection of the 5 wires can result in both heating and hot water firing simultaneously, neither zone operating, or damage to thermostats. Where the old head is a 6-wire type (pre-1990 installations with external relay), specific wiring changes are required — see the Honeywell installation guide (95C-10656).\n  \u003c\/div\u003e\n\n  \u003c!-- ── STAT STRIP ─────────────────────────────────────────────────── --\u003e\n  \u003cdiv style=\"display:flex;flex-wrap:wrap;gap:10px;margin-bottom:20px;\"\u003e\n    \u003cdiv style=\"flex:1;min-width:90px;background:#008377CF;color:#fff;border-radius:6px;padding:11px 8px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:16px;font-weight:700;\"\u003eV4073A\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;margin-top:3px;\"\u003eMid-position valve\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:90px;background:#008377CF;color:#fff;border-radius:6px;padding:11px 8px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:16px;font-weight:700;\"\u003e5-wire\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;margin-top:3px;\"\u003eY-plan systems\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:90px;background:#008377CF;color:#fff;border-radius:6px;padding:11px 8px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:16px;font-weight:700;\"\u003eNo drain\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;margin-top:3px;\"\u003ePost-1987 valves\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:90px;background:#008377CF;color:#fff;border-radius:6px;padding:11px 8px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:16px;font-weight:700;\"\u003e6W\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;margin-top:3px;\"\u003ePower consumption\u003c\/div\u003e\n\u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:90px;background:#008377CF;color:#fff;border-radius:6px;padding:11px 8px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:16px;font-weight:700;\"\u003e8.6 bar\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;margin-top:3px;\"\u003eMax static pressure\u003c\/div\u003e\n\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- ── FEATURES GRID ──────────────────────────────────────────────── --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;font-weight:600;font-size:15px;padding:10px 16px;border-radius:6px 6px 0 0;\"\u003eFeatures \u0026amp; Benefits\u003c\/div\u003e\n  \u003cdiv style=\"display:grid;grid-template-columns:repeat(auto-fill,minmax(255px,1fr));gap:12px;background:#e6f4f3;padding:14px;border-radius:0 0 6px 6px;margin-bottom:22px;\"\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ No System Drain — Post-1987 Direct Swap\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eOn \u003cstrong\u003epost-1987 V4073A valves\u003c\/strong\u003e (identified by the bump on the cover), the powerhead can be replaced \u003cstrong\u003ewithout draining the heating system\u003c\/strong\u003e. The valve body remains in the pipework; the existing head is removed with two screws; the replacement head is fitted with the manual lever in the MAN. OPEN position to seat it correctly, secured with the two supplied screws, and wired back. This eliminates the disruption of draining, refilling, bleeding, and recommissioning the entire system — which on a pressurised sealed system can add an hour or more to what is otherwise a straightforward component swap. The system pressure is maintained throughout; only the actuator assembly is disturbed.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ Genuine Honeywell Part — OEM Quality\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eThis is the \u003cstrong\u003egenuine Honeywell Home (Resideo) replacement powerhead\u003c\/strong\u003e — manufactured by Pittway Sarl in Hungary to the same specification as the original factory-fitted head. The motor, microswitch assembly, spring-return mechanism, and manual lever are all OEM components. Using the genuine part ensures correct torque specification for the valve stem, correct microswitch switching points for the auxiliary switch output (which signals the boiler and pump), and the spring-return force matched to the V4073A body's flow characteristic. Third-party substitute heads may not match these parameters, risking intermittent operation or incomplete valve travel.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ Spring-Return Mid-Position Operation\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eThe V4073A mid-position valve — and therefore this replacement head — uses \u003cstrong\u003espring-return action\u003c\/strong\u003e to deliver the valve's three operating states: \u003cstrong\u003ehot water only\u003c\/strong\u003e (valve in HW port, spring holds the diverter closed to CH), \u003cstrong\u003emid-position\u003c\/strong\u003e (both HW and CH ports open — motor powered against spring), and \u003cstrong\u003ecentral heating only\u003c\/strong\u003e (valve fully driven, HW port closed). The spring return ensures that on power loss, the valve defaults to the hot water position — a fail-safe behaviour built into Y-plan system design. The motor drives the valve against the spring to reach mid-position; the auxiliary microswitch fires when both circuits are satisfied by the boiler.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ Manual Lever — AUTO and MAN. OPEN Positions\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eThe powerhead incorporates a \u003cstrong\u003emanual override lever\u003c\/strong\u003e with two positions: \u003cstrong\u003eAUTO\u003c\/strong\u003e (normal electrical operation) and \u003cstrong\u003eMAN. OPEN\u003c\/strong\u003e (valve held physically open for drain-down or system filling). Moving the lever to MAN. OPEN allows water to flow through the valve regardless of whether the motor is powered — essential for filling a pressurised sealed system or bleeding the system after maintenance work. The lever must be returned to \u003cstrong\u003eAUTO before normal operation resumes\u003c\/strong\u003e; leaving it in MAN. OPEN will bypass all thermostat control. During the head replacement procedure, the lever is placed in MAN. OPEN to allow the head to seat correctly on the valve body shaft.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ 1 Metre Pre-Wired Lead Supplied\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eThe replacement head is supplied \u003cstrong\u003efactory-wired with a 1 metre lead\u003c\/strong\u003e terminated in the standard 5-wire colour code used in UK Y-plan heating systems. The five conductors are: \u003cstrong\u003eneutral (blue), live 230V in (brown), orange (HW demand — drives motor to mid-position), white (CH demand — drives motor fully open), grey (auxiliary switch output — fires boiler and pump)\u003c\/strong\u003e. The supplied lead length is sufficient for most installations where the junction box is located adjacent to the valve; where longer runs are needed, the existing junction box wiring is retained and only the short tail from head to junction box is replaced.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"background:#f0faf9;border:1px solid #c8e6e3;border-radius:6px;padding:13px;\"\u003e\n      \u003cdiv style=\"font-weight:700;color:#008377CF;margin-bottom:5px;\"\u003e✔ Save vs Full Valve Replacement\u003c\/div\u003e\n      \u003cdiv style=\"font-size:14px;\"\u003eWhen a V4073A motorised valve fails, the instinctive response is often to replace the entire valve — body, connections, and all. In the majority of cases, \u003cstrong\u003eonly the powerhead has failed\u003c\/strong\u003e: the valve body, seats, and pipework connections are sound and have decades of remaining service life. Replacing only the powerhead with this genuine part avoids cutting into the pipework, replacing compression fittings or solder joints, and the associated risk of joint failure after reassembly. The cost and labour saving over a full valve replacement is significant, and the result is functionally identical — the same new motor and microswitch assembly is installed in either case.\u003c\/div\u003e\n    \u003c\/div\u003e\n\n  \u003c\/div\u003e\n\n  \u003c!-- ── COMPATIBILITY TABLE ────────────────────────────────────────── --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;font-weight:600;font-size:15px;padding:10px 16px;border-radius:6px 6px 0 0;\"\u003eCompatible V4073A Valve Models\u003c\/div\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;margin-bottom:22px;font-size:14px;\"\u003e\n    \u003cthead\u003e\n      \u003ctr style=\"background:#005c54;color:#fff;\"\u003e\n        \u003cth style=\"padding:9px 12px;text-align:left;font-weight:600;border-bottom:2px solid #008377CF;\"\u003eValve Model\u003c\/th\u003e\n        \u003cth style=\"padding:9px 12px;text-align:left;font-weight:600;border-bottom:2px solid #008377CF;\"\u003eNotes\u003c\/th\u003e\n        \u003cth style=\"padding:9px 12px;text-align:left;font-weight:600;border-bottom:2px solid #008377CF;\"\u003eAdaptor Required?\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eV4073A1039\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003ePost-1987 — bump visible on cover\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003eNo — direct fit\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eV4073A1054\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003ePost-1987 — bump visible on cover\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003eNo — direct fit\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eV4073A1062\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003ePost-1987 — bump visible on cover\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003eNo — direct fit\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eV4073A1088\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003ePost-1987 — bump visible on cover\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border-bottom:1px solid #c8e6e3;\"\u003eNo — direct fit\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:8px 12px;font-weight:600;\"\u003ePre-1987 V4073 (OS suffix \u0026lt;6, no bump, 4 screws)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003eFlat cover, four-screw attachment\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e\u003cstrong\u003eYes — 40003918-007 adaptor kit required\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003c!-- ── SPEC TABLE ─────────────────────────────────────────────────── --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;font-weight:600;font-size:15px;padding:10px 16px;border-radius:6px 6px 0 0;\"\u003eTechnical Specifications — 40003916-003\/U\u003c\/div\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;margin-bottom:22px;font-size:14px;\"\u003e\n    \u003ctbody\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;width:44%;border-bottom:1px solid #c8e6e3;\"\u003eManufacturer \/ MPN\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003eHoneywell Home (by Resideo) — \u003cstrong\u003e40003916-003\/U\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eGTIN\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e5023220401476\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eApplication\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003eReplacement powerhead for V4073A 3-port mid-position motorised valves — 5-wire Y-plan systems\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003ePower Supply\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e230V ~ 50Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003ePower Consumption\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e\u003cstrong\u003e6W\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eLead Supplied\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e\n\u003cstrong\u003e1 metre\u003c\/strong\u003e — 5-wire colour-coded\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eValve Operation\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003eSpring-return — mid-position (3-port)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eMax. Load (Inductive)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e2.2A\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eMax. Load (Resistive)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e2.2A\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eMax. Static Pressure\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e8.6 bar\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eOperating Temperature Range\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e+5°C to +88°C (fluid)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eMax. Ambient Temperature\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e+52°C\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eManual Override\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003eYes — AUTO \/ MAN. OPEN lever\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eFixing Method\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e2 screws + 2 locating pegs (new-style bodies)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eGross Weight (inc. packaging)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e0.522 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003eHungary (manufactured by Pittway Sarl for European region)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;border-bottom:1px solid #c8e6e3;\"\u003eBritish Gas Reference\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;border-bottom:1px solid #c8e6e3;\"\u003e378454\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;\"\u003e\n\u003cstrong\u003e1 year\u003c\/strong\u003e — Honeywell Home manufacturer's warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003c!-- ── FAQ ────────────────────────────────────────────────────────── --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;font-weight:600;font-size:15px;padding:10px 16px;border-radius:6px 6px 0 0;\"\u003eFrequently Asked Questions\u003c\/div\u003e\n  \u003cdiv style=\"border:1px solid #c8e6e3;border-top:none;border-radius:0 0 6px 6px;margin-bottom:8px;\"\u003e\n\n    \u003cdetails style=\"border-bottom:1px solid #c8e6e3;\"\u003e\n      \u003csummary style=\"padding:13px 16px;cursor:pointer;font-weight:600;background:#f0faf9;\"\u003eWhat is the difference between the \"-003\" and \"-001\" suffix — can I use \"-001\" on a 3-port valve?\u003c\/summary\u003e\n      \u003cdiv style=\"padding:11px 16px;font-size:14px;\"\u003e\n\u003cstrong\u003eNo\u003c\/strong\u003e — the suffix matters. The \u003cstrong\u003e40003916-003\/U\u003c\/strong\u003e is the \u003cstrong\u003e5-wire head for the V4073A mid-position (3-port) valve\u003c\/strong\u003e used in Y-plan systems — it contains the motor, spring, and microswitch wired for both heating and hot water demand signals plus the auxiliary boiler output. The \u003cstrong\u003e40003916-001\u003c\/strong\u003e is the 2-wire head for 2-port zone valves (V4043\/V4044 series) used in S-plan systems — different internal wiring, different microswitch function, different mechanical travel. Fitting a \"-001\" head to a 3-port body, or vice versa, will result in incorrect valve function and potential wiring damage.\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails style=\"border-bottom:1px solid #c8e6e3;\"\u003e\n      \u003csummary style=\"padding:13px 16px;cursor:pointer;font-weight:600;background:#fff;\"\u003eMy valve is humming but not moving — is the powerhead definitely the cause?\u003c\/summary\u003e\n      \u003cdiv style=\"padding:11px 16px;font-size:14px;\"\u003eA continuous hum with no valve movement is a strong indicator of a \u003cstrong\u003emotor winding failure or seized motor\u003c\/strong\u003e — typically the powerhead. However, before replacing, it is worth checking: (1) the manual lever — if it has been left in MAN. OPEN, the valve won't respond to electrical signals; (2) the wiring connections — a loose or corroded terminal can cause erratic behaviour; (3) the valve body itself — in rare cases the spindle can seize in the body rather than the motor failing. To test the body independently, move the manual lever to MAN. OPEN and check if water flows through the correct port. If the body appears free and the wiring is sound, the powerhead is almost certainly the fault. Replacing the powerhead first is the correct diagnostic step before considering full valve replacement.\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails style=\"border-bottom:1px solid #c8e6e3;\"\u003e\n      \u003csummary style=\"padding:13px 16px;cursor:pointer;font-weight:600;background:#f0faf9;\"\u003eAfter fitting, my central heating and hot water both come on together — what's wrong?\u003c\/summary\u003e\n      \u003cdiv style=\"padding:11px 16px;font-size:14px;\"\u003eThis is the most common post-installation symptom and is almost always a \u003cstrong\u003ewiring error\u003c\/strong\u003e, not a faulty head. The five wires from the valve connect to: neutral (blue), live (brown), hot water demand (orange — drives motor to mid-position), central heating demand (white — drives motor fully open), and auxiliary output (grey — fires the boiler\/pump). If orange and white are swapped, both zones will fire simultaneously. Cross-reference your wiring against the Honeywell installation guide 95C-10656, paying particular attention to the auxiliary switch output on grey — this wire must only be connected once the valve reaches its end position. If replacing a 6-wire valve with an internal relay, specific additional wiring changes are required — the brown wire from the old relay is omitted and the cylinder thermostat C and 1 terminals must be reversed.\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails style=\"border-bottom:1px solid #c8e6e3;\"\u003e\n      \u003csummary style=\"padding:13px 16px;cursor:pointer;font-weight:600;background:#fff;\"\u003eDo I need to isolate the boiler before replacing the head?\u003c\/summary\u003e\n      \u003cdiv style=\"padding:11px 16px;font-size:14px;\"\u003eYes — \u003cstrong\u003eall electrical power to the heating system must be isolated\u003c\/strong\u003e before starting work. This means switching off at the programmer\/time control, at the system's unswitched fused spur, or at the consumer unit's heating circuit. The valve operates at 230V and is connected to the wiring centre alongside the boiler, pump, and thermostats — live conductors are present in the junction box and at the valve terminals even when the heating is not actively calling. A shock from incorrectly isolated wiring at a junction box is a serious risk. Isolation must be confirmed with a voltage tester before any electrical connections are disturbed.\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary style=\"padding:13px 16px;cursor:pointer;font-weight:600;background:#f0faf9;\"\u003eCan this head convert a 3-port diverter valve to a mid-position valve?\u003c\/summary\u003e\n      \u003cdiv style=\"padding:11px 16px;font-size:14px;\"\u003eYes — in principle. A 3-port diverter (V4043 body) and a 3-port mid-position valve (V4073A body) use a similar physical construction, and the 40003916-003 powerhead can be fitted to a V4043 body, converting it electrically from a diverter to a mid-position configuration. The full Y-plan wiring (5-wire: neutral, live, orange HW, white CH, grey auxiliary) must then be connected correctly. However, \u003cstrong\u003ebefore doing this, confirm the V4043 body valve seats are compatible with mid-position operation\u003c\/strong\u003e — a diverter valve is designed to fully route flow to one port or the other, while a mid-position valve is designed to allow partial flow through both ports simultaneously. If the body seating is not designed for this, mid-position flow balance may not be correct. Consult the Honeywell installation guide and a qualified heating engineer before proceeding.\u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":64292701602141,"sku":"40003916-003\/U","price":99.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/head-40003916-003-honeywell.webp?v=1776842078","url":"https:\/\/qualityheating.co.uk\/products\/honeywell-home-40003916-003-u-replacement-actuator-powerhead-v4073a-3-port-mid-position-5-wire-motorised-valve","provider":"AIZO Quality Heating","version":"1.0","type":"link"}