The Honeywell Home MT4-230-NC is a small linear thermoelectric actuator built for precise, noiseless control of heating and cooling valves in room and zone applications. It is designed for time-controlled two-point or pulse-width modulated (PWM) regulation of fan coil units, radiators, underfloor heating manifolds, chilled ceilings and convectors, making it a reliable choice for both residential and light commercial zoning systems.
Running from a 230V AC supply and fitting standard M30 x 1.5 valve threads, this normally-closed (NC) actuator uses a wax-element drive mechanism to deliver strong, consistent stem force with no motor noise. A tool-free snap-on valve adapter and pluggable cable keep installation and future servicing straightforward, while a visual position indicator shows the actuator's current state at a glance.
230V AC
Power Supply
4 mm
Max Stroke
90 N
Stem Force
IP44
Protection Rating
M30 x 1.5
Valve Fitting
Normally Closed
Valve Action
Normally Closed (NC) Model
This is the normally-closed (NC) version: on a standard 2-way valve, A-B is shut when the actuator has no power, and the stem extends to open the valve when energised. If a normally-open (NO) action is needed for your system design, confirm you are ordering the correct MT4-230-NO variant instead.
PWM Compatibility
For pulse-width modulated (PWM) operation, Honeywell Home recommends pairing this actuator with Excel 10 or Excel 12 controllers. Use with third-party, non-Honeywell Home controllers may adversely affect PWM performance.
Qualified Installation Required
This actuator connects to a 230V AC mains supply. Electrical connection should be carried out by a competent, qualified installer in accordance with current UK wiring regulations.
Tool-Free Snap-On Mounting
A snap-on valve adapter means no tools are required for mounting, making installation and future replacement fast on standard M30 x 1.5 valve threads.
Visual Position Indicator
A red indicator behind the face window clearly shows the actuator's current stroke position and confirms its normally-open or normally-closed type of action at a glance.
Water-Protected IP44 Housing
Rated IP44 in all mounting positions, the housing is protected against splashing water, suiting installation in a wide range of orientations around heating and cooling systems.
Noiseless, Long-Life Operation
A wax-element thermal drive delivers smooth, silent stroke movement with no motor noise, backed by robust construction for reliable long-term performance.
Pluggable Cable for Easy Servicing
The plug-in cable simplifies both initial wiring and any future servicing or replacement, reducing time spent on site.
Built-In Overload Protection
230V models include 4 kV overload protection, adding a layer of electrical resilience against voltage spikes.
General
Model / MPN
MT4-230-NC
EAN Code
4019837107307
Product Family
MT4/MT8 Small Linear Thermoelectric Actuators
Valve Action
Normally closed (NC)
Maximum Stroke
4 mm
End Position
14.0 mm
Electrical
Power Supply
230 V AC +10% / -15%, 50 Hz
Power Consumption
< 2 VA
Initial Current
~0.4 A (average, first 500 ms)
Permanent Current
< 0.01 A
Overload Protection
4 kV (230V models)
Cable Length
1 m
Cable Wires
2 x 0.5 mm²
Mechanical & Environmental
Stem Force
90 N
Valve Fitting
Standard M30 x 1.5 heating/cooling valves and manifold inserts
Closing Dimension
11.5 mm ± 0.3 mm
Runtime, Full Nominal Stroke
Approx. 4.0 minutes
Protection Standard
IP44 in all mounting positions
Max Medium Temperature
120 °C
Operating Ambient Temperature
20 °C to 50 °C
Max Ambient Humidity
95% (non-condensing)
Dimensions (H x L x W)
59 x 45 x 42 mm
Approvals & Warranty
Approvals
CE, UKCA
Warranty
1 year
What does 'normally closed' mean for this actuator?
On a standard 2-way valve, normally closed (NC) means the valve stays shut when the actuator has no power, and the stem extends to open it once energised. This is the opposite of a normally-open (NO) model, so it's worth confirming which action your system design calls for before ordering.
What valves is the MT4-230-NC compatible with?
It fits standard M30 x 1.5 heating and cooling valves, thermostatic radiator valves, and valve inserts used on manifolds and compact radiators, matching the common 11.5 mm ± 0.3 mm closing dimension. Special valve adapters are available on request for other valve types.
Do I need any tools to fit this actuator?
No. The actuator uses a snap-on valve adapter, so it mounts and dismounts without tools, making installation and future servicing quick and straightforward.
Can this actuator be used for PWM (pulse-width modulated) control?
Yes, the MT4-230-NC supports both two-position (on/off) and PWM control. For best PWM performance, Honeywell Home recommends pairing it with Excel 10 or Excel 12 controllers, as third-party controllers may affect PWM operation.
What does the position indicator show?
The red indicator behind the face window shows both the actuator's type of action (NO or NC) and its current stroke position, giving a quick visual check of valve status without opening the unit.
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
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