What Does A Motorised Valve Do?
If you’ve ever worked on a zoned heating system, you’ll already know how important motorised valves are. In simple terms, a motorised valve opens or closes in response to a signal from the heating controls, allowing hot water to flow to heating circuits, hot water cylinders, or both.
They’re commonly used to control individual heating zones, separate heating and hot water demands and improve efficiency and comfort in larger or zoned properties. Different systems use different valve layouts, which is why choosing the right type of motorised valve matters.
Types Of Motorised Valves Explained
Looking to control one heating zone or a hot water cylinder separately? A 2-port zone valve is usually the go-to choice. These valves have one inlet and one outlet and will control the flow of water to a single circuit. They are most commonly found in S-Plan systems, where heating zones and hot water are controlled independently. We stock 2-port motorised valves in 22mm and 28mm, as well as BSP options, from leading manufacturers.
A 3-port mid-position valve has one inlet and two outlets and is designed to direct water to heating, hot water or both at the same time. These valves are typically used in Y-Plan systems and are a popular choice where a single valve manages both heating and hot water demand, offering flexibility without multiple zone valves. Standard sizes include 22mm and 28mm, with well-known options such as the Honeywell Home V4073A.
A 3-port diverter valve also has one inlet and two outlets, but unlike a mid-position valve, it directs water to one outlet at a time, not both simultaneously. These valves are used in specific system designs where heating and hot water are not required at the same time. BES stocks Drayton diverter valves in 22mm and 28mm sizes.
Our Range Of Motorised Valves & Replacement Parts
As a long-established trade supplier, BES stocks not only a wide choice of motorised valves, but also the parts needed to maintain and repair them.
Our range includes reliable 2-port motorised valves in standard sizes from trusted brands, as well as cost-effective alternatives for straightforward installations. Popular options include Drayton Motorised Zone Valve - 2 Port 22mm, Honeywell Home V4043B Motorised Zone Valve - 2 Port 22mm and Honeywell Home V4043B Motorised Zone Valve - 2 Port 22mm.
Our 3-port mid-position valves are ideal for Y-Plan systems and are available in both standard and rotary shoe designs. Top choices include Drayton Motorised Mid-position Valve - 3 Port 22mm, ZVM22 Motorised Mid-position Valve - 3 Port 22mm and Honeywell Home V4073A Mid-Position Valve - 3 Port 22mm.
For systems that require directional control rather than mid-position operation, our 3-port diverter valves offer a dependable solution. Our selection includes Drayton Motorised Diverter Valve - 3 Port 22mm and Drayton Motorised Diverter Valve - 3 Port 28mm.
If the valve body is still sound, a replacement motorised valve head can often be fitted without draining the system, making repairs quicker and less disruptive. Motorised Zone Valve Replacement Head - 2 Port and Motorised Valve Replacement Head - 3 Port Mid-Position are among the most popular in the range.
Working with an older valve body? Valve head conversion kits allow compatible older valves to be upgraded so they can accept modern, replaceable heads. Choose from Honeywell Home Power Head Conversion Kit for P/N 12130, Honeywell Home Power Head Conversion Kit P/N 12131 & 12132 and Powerhead Replacement Kit.
When only the motor has failed, replacement synchronous motors provide a cost-effective way to restore operation without replacing the full valve. Popular choices include the Replacement Synchronous Motor and Drayton Replacement Synchron Motor - 230V.
To support installation and maintenance work, we also stock wiring connectors, such as Wiring Connector - 3 to 5 Way, helping keep connections tidy and secure inside wiring centres.
Choosing The Right Size & Compatibility
Motorised valves are most commonly supplied in 22mm and 28mm, selected to match existing pipework. Some systems may also use BSP connections, particularly in older or specialised installations. When replacing a valve or component, it’s important to check the pipe size and connection type, whether the system uses a 2-port or 3-port layout and compatibility between valve bodies, heads and motors. If you’re unsure, replacing like-for-like is often the safest option.
Better Deals On Motorised Valves
BES has been the choice of many in the trade for over 50 years – our knowledge and experience ensure we stock everything needed, no matter the project at hand.
And with an Excellent rating from reviews.co.uk, you can trust us too for all your central heating needs – our range includes heating pumps, expansion vessels, valves, controls, boiler equipment, and so much more.
Prompt Delivery Of Your New Motorised Valve
As with most equipment, parts, or tools, there are a few things you need to consider before buying a motorised valve, including ensuring your heating system can use them. If you have any questions about any of our products, just get in touch, and the BES team will be happy to provide expert advice.
Motorised Valves FAQs
What’s the difference between a 2-port and 3-port motorised valve?
A 2-port valve controls flow to a single circuit, while a 3-port valve directs flow between two circuits, such as heating and hot water.
What’s the difference between a mid-position and a diverter valve?
A mid-position valve can supply heating, hot water or both at the same time. A diverter valve sends water to one outlet at a time.
Can I replace just the motorised valve head without draining the system?
In many cases, yes. Many modern valves are designed with replaceable heads, provided the valve body is compatible.
Are motorised valves interchangeable between brands?
Not always. While sizes may match, heads, motors and wiring can differ between manufacturers.
Do you sell replacement motors and accessories?
Yes, BES stocks replacement motors, heads, conversion kits and wiring accessories to support repairs and maintenance.
Can I replace just the motorised valve head without draining the system?
In many cases, yes. Many modern motorised valves are designed with replaceable actuator heads, allowing the head to be changed without draining down the system. Compatibility depends on the valve body and manufacturer, so it’s always best to check before replacing.
What is a motorised valve conversion kit used for?
A motorised valve conversion kit allows certain older valve bodies to be upgraded so they can accept modern, replaceable actuator heads. This can be a practical option when maintaining older heating systems, provided the valve body is suitable.
What’s the difference between a mid-position valve and a diverter valve?
A mid-position valve can supply heating, hot water, or both at the same time and is commonly used in Y-Plan systems. A diverter valve directs water to one outlet at a time, switching between heating and hot water depending on demand.
How do I choose the correct size motorised valve?
Most domestic central heating systems use 22mm motorised valves, with 28mm valves typically used where higher flow rates are required. The correct size should match the existing pipework to maintain system performance.
Are motorised valves interchangeable between brands?
Motorised valves are not always interchangeable between brands. While pipe sizes may match, actuator heads, motors and wiring arrangements can differ. Replacing like-for-like or checking manufacturer guidance is recommended.
Do you stock replacement motors and accessories for motorised valves?
Yes, BES supplies replacement motors, actuator heads, conversion kits and wiring accessories to support the repair and maintenance of motorised valves across a range of popular brands.
