The Honeywell Home V4044C1288 22mm 3 Port Diverter Valve is a motorised valve designed to control the flow of water between heating and hot water circuits in domestic fully pumped central heating systems, allowing flow to only one zone at a time.
Manufactured by Resideo under the Honeywell Home brand, this valve is the standard control component for the Sundial W Plan hot water priority system, directing boiler output either to the radiator circuit or the hot water cylinder. It features a 3-wire, spring return powerhead that can be replaced without draining down the system, making servicing straightforward for installers.
8.6 bar
Max Operating Pressure
88°C
Max Media Temperature
⚠ Important Safety Information
This valve
must not be fitted on the return pipework under any circumstances. Boiler flow connects to port AB, the radiator circuit to port A, and the hot water cylinder circuit to port B. It must also not be mounted with the valve head below the horizontal level of the pipework.
Key Features
Spring Return Powerhead
The spring return action ensures the valve fails safely, defaulting the ball position when power is removed.
Powerhead Replaceable Without Draindown
The motorised head can be removed and replaced without draining the system, significantly reducing service time and disruption.
Manual Lever for Filling and Draining
A built-in manual override lever allows the ball to be centred manually to assist with system filling and draindown procedures.
Two-Position Diverter Operation
Controls flow between AB-A and AB-B ports, directing the boiler's output to either the heating circuit or the hot water cylinder — never both simultaneously.
Quiet, Low-Power Operation
Draws just 6W of power during operation, with quiet running suited to domestic installations near living spaces.
Complete With 1 Metre Flying Lead
Supplied with a 1 metre, 5-core heat-resistant cable ready for connection to a Resideo junction box on a 230V AC supply.
Technical Specification
Electrical
Supply voltage230-240V AC ~ 50Hz
Power consumption6W
Lead supplied1 metre, 5-core
ControlLine voltage, single pole single throw
Mechanical & Connections
Valve typeMid-position / 3-port diverter valve
Pipe connection22mm compression fitting
Number of ports3 (AB, A, B)
Body materialBrass
Ball materialNBR
Valve seat materialZinc
Width112mm
Height133mm
Depth60mm
Performance
Maximum operating pressure8.6 bar
Maximum close-off differential pressure0.69 bar
Maximum media temperature88°C
Minimum media temperature5°C
Maximum ambient air temperature52°C
Minimum ambient temperature5°C
System capacityUp to 90,000 Btu/h (26kW)
Application & Compatibility
System typeDomestic fully pumped central heating
Compatible system planSundial W Plan hot water priority
Manufacturer part numberV4044C1288/U
Replacement motor40002737-003
Replacement powerhead40003916-002
Ball & O-ring kit272742A CARD
ℹ Please Note
Wiring must connect boiler flow to
port AB, the radiator circuit to
port A, and the hot water cylinder circuit to
port B. Installation must be carried out by a competent person in accordance with I.E.E. Regulations and the Electricity at Work Regulations, with a Class A isolating switch incorporated in the fixed wiring.
Frequently Asked Questions
What system is this valve designed for?
The V4044C1288 is built for the Sundial W Plan hot water priority system, used in domestic fully pumped central heating systems up to 26kW (90,000 Btu/h).
Can the powerhead be replaced without draining the system?
Yes — the powerhead is replaceable without draining down, allowing faster servicing compared with valves that require a full system drain.
Which port does the boiler connect to?
Boiler flow connects to port AB. The radiator circuit connects to port A, and the hot water cylinder circuit connects to port B. The valve must never be fitted on the return pipework.
What is the manual lever used for?
The manual lever centres the internal ball to assist with filling and draining down the system. It should be returned to the 'AUTO' position for normal operation.
Can this valve be installed at any angle?
It may be plumbed in at any angle, but must not be mounted with the valve head below the horizontal level of the pipework, as this could create a safety hazard in the event of a leak.
