The Honeywell Home V4043H1056/U is a 22mm two-port motorised zone valve for domestic and light commercial central heating systems — the most widely installed zone valve in the UK, standard across S-plan, Y-plan, and S-plan-plus wiring configurations. Motor open and spring return, with a normally closed fail-safe position (valve closes when de-energised), a potential-free SPST end switch for boiler and pump control, and a replaceable powerhead that does not require draining the system. Manual lever for filling and draining. 1 metre heat-resistant flying lead. Compatible with all standard wiring centres, programmers, and zone controllers. Maximum static pressure 8.6 bar; fluid temperature +5°C to +88°C.
ℹ S-Plan & Y-Plan Use — In an S-plan system (the most common UK configuration), two V4043H1056 zone valves are installed: one on the heating circuit and one on the hot water circuit. Each valve's end switch fires the boiler and runs the pump only when that zone is calling, providing independent control of heating and hot water. In a Y-plan configuration a single three-port mid-position valve is used instead — the V4043H1056 is a two-port (on/off) valve, not a mid-position valve.
Features & Benefits
✔ Motor Open, Spring Return — Fail-Safe Closed
The V4043H uses a motor to open the valve and a return spring to close it. When the wiring centre calls for heat and sends power to the valve, the motor drives the valve open over approximately 12 seconds; when the call ends and power is removed, the return spring snaps the valve closed in about 5–6 seconds — no electrical power required to close. This normally closed, fail-safe design means that in the event of a power failure or wiring fault, the valve defaults to closed, preventing uncontrolled heating circulation.
✔ Potential-Free End Switch — Boiler & Pump Control
The potential-free (volt-free) auxiliary end switch closes as the valve reaches its fully open position. This switch signal is used to fire the boiler and/or start the circulating pump — ensuring the boiler only fires when at least one zone valve is fully open and water is circulating. This is the fundamental boiler interlock mechanism in S-plan and Y-plan wiring configurations. The end switch must be wired to the boiler's live connection (via the wiring centre) to achieve Part L-compliant boiler interlock.
✔ Replaceable Powerhead — No Drain-Down
The motor head (powerhead) can be removed and replaced without draining the heating system. The valve body remains in the pipework; the motorised head clips or screws on and off independently. If the motor fails — by far the most common V4043 failure — the entire valve does not need to be cut out of the pipework. The powerhead can be swapped in minutes with the system full and under pressure, making maintenance on a live system fast and cost-effective.
✔ Manual Lever — Filling and Draining
A manual lever on the valve body allows the valve to be held open manually when filling or draining the heating system — without requiring electrical power to the actuator. This is essential during commissioning (the system needs to circulate water for flushing and chemical treatment) and during drain-down for maintenance on other components. Push the lever to open manually; release to allow the return spring to close.
✔ Quiet Operation — 5W Power Consumption
The synchronous motor is designed for near-silent operation — the only noise during opening is a brief mechanical engagement, not a continuous motor whine. Once fully open, the motor stalls and the end switch holds the boiler on; there is no continuous motor running sound during the heating period. At only 5W power consumption, the valve adds negligible electrical load — far less than the boiler's control electronics.
✔ 22mm Compression — Industry Standard
Standard 22mm compression fittings — the V4043H is the most widely installed motorised zone valve in the UK and is the valve that all standard wiring centre diagrams, S-plan and Y-plan configurations, and installer training are based around. Being the default component in UK heating design means replacement availability is guaranteed and any qualified plumber or heating engineer will be able to install, wire, and commission it correctly without reference to unusual procedures.
Technical Specifications
| Manufacturer / Part No. |
Honeywell Home (Resideo) — V4043H1056/U
|
| Connection Size |
22mm compression |
| Number of Ports |
2-port (on/off) |
| De-energised State |
Normally CLOSED (spring return) |
| Action |
Motor open — spring return |
| Supply Voltage |
220–240V AC, 50/60Hz |
| Power Consumption |
5W |
| End Switch Type |
SPST — potential-free |
| Switch Rating |
250VAC, 4A |
| Opening Time |
12 seconds (nominal) |
| Closing Time |
5–6 seconds (spring return) |
| Max Static Pressure |
8.6 bar |
| Max Differential Pressure (close-off) |
0.55 bar |
| Kv Value |
6.9 |
| Fluid Temperature Range |
+5°C to +88°C |
| Max Ambient Temperature |
+50°C |
| Electrical Connection |
1.0m heat-resistant flying lead |
| Dimensions (H × W × D) |
98 × 112 × 60 mm |
| Weight |
1.0 kg |
| Flow Direction |
As per arrow on valve body |
