Drayton 28mm Motorised 3 Port Mid-Position Valve & Snap-On Actuator

Drayton 28mm Motorised 3 Port Mid-Position Valve & Snap-On Actuator (6 Wire SPDT Switch) – MPN: 27206 is a high-quality, UK-manufactured mid-position valve assembly for domestic wet central heating systems. It features a 3-port brass valve body with 28mm compression connections and a 230V snap-on actuator with 6-core SPDT switch wiring, allowing the system to supply central heating, hot water, or both simultaneously in a classic Y-Plan configuration.

Key Features

• 3-port mid-position control – directs flow to hot water only, heating only or both circuits together, ideal for Y-Plan systems with a cylinder and radiators.
• 28mm compression connections – larger-bore valve body with 28mm compression fittings for higher flow rates and reduced pressure drop on bigger systems.
• Snap-on actuator – actuator can be removed and replaced at the push of a button, without draining the system, simplifying maintenance and upgrades.
• 6-wire SPDT switch – industry-standard 6-core wiring (SPDT microswitch) for straightforward connection to most modern wiring centres.
• Spring-return mechanism – power-to-open / spring-return design fails the valve back to a safe position on power loss.
• 100% tight shut-off – engineered for positive closure, helping to prevent unwanted flow and bypassing.
• Manual lever & position indicator – allows manual operation and visual confirmation of valve position during filling, testing or emergency use.
• Replaceable motor and actuator – both actuator and motor can be replaced as spare parts, extending system life and reducing disruption.

Technical Highlights

• Manufacturer: Drayton (Motorised Valves range).
• Model / Part: MA1/779-3 28mm 3-port mid-position valve, complete with actuator (Part No. 27206).
• Valve type: 3-port mid-position (heating, hot water, or a combination of both).
• Connections: 28mm compression.
• Body material: brass forging.
• Standard motor voltage: 230V AC, 50Hz, approximately 5W.
• Action: Type 1.C, power to open, spring return.
• Max static pressure: 8.6 bar.
• Max differential pressure: approx. 0.7 bar (28mm mid-position).
• Water temperature range: 2°C to 93°C.
• Max ambient temperature: 52°C.
• Flow characteristic (Kv): approx. 7.0 for 28mm mid-position model.
• Lead length: 1 metre, 6-core cable.
• Switch rating: 24–230V AC, 3(1)A.
• Approx. dimensions (28mm mid-position): height ~150mm, valve body length ~105mm, overall width ~150mm (see Drayton datasheet for exact A–F dimensions).
• Standards: conforms to EN 60730-1 and related control standards.

Typical Applications

• Traditional Y-Plan domestic heating systems with one heating zone and one stored hot water cylinder.
• Upgrades and replacements where an existing 28mm 3-port mid-position valve is fitted and industry-standard wiring is already in place.
• Larger domestic properties or small commercial systems requiring higher flow through 28mm primary pipework.

Installation Notes

• Valve body should be installed by a competent heating engineer, observing correct flow direction (usually from bottom port) and system flushing/cleaning best practice.
• The snap-on actuator can often be fitted or replaced without draining the system, but always follow Drayton’s installation instructions and isolate power before work.
• Use the standard 6-wire SPDT wiring diagram (Y-Plan) in the wiring centre, ensuring correct connections to room stat, cylinder stat and boiler.
• Ensure the valve is accessible for future servicing, with space to remove the actuator and view the position indicator and manual lever.