Hydronic accessories

Thermal Actuator

Two-wire 24V slow opening thermal actuator (without end switch) for radiant cooling and heating manifolds.

It is compatible with most common manifolds using a standard threaded ring adapter. It comes with a VA10 ring adapter that also works with the Messana manifold (other adapters are available).

The actuator mounts on the manifold loop by snapping onto the pre-installed ring adapter. It is normally closed (NC), when energized, it opens the loop valve to activate the related zone.

The actuator mechanism is based on a PTC resistor-heated elastic element and a return compression spring. When the elastic element is heated by applying the nominal 24V voltage to the PTC resistor, it expands and moves an integrated plunger to open the valve. When the PTC resistor is no longer energized, the elastic element shrinks and
the return compression spring moves the plunger back and closes the valve.

Messana Thermal Actuator

Technical specifications

Table Header
Two-wire thermal actuator (without end switch)
Part number
Easy snap-on installation on standard ring valve adapter (VA10 adapter included)
360° installation position and rotation
Compatible with the majority of manifold on the market
Normally closed (NC) 5 ft of cable compared to standard 3ft
Visible blue ring to visually indicate the actuator status (blue ring is shown when open)
First-open function (actuator comes partially open, until the first activation, for 6 minutes minimum)
5 ft of cable (compared to standard 3 ft)
Compact modern design and quite operation
Superior reliability with long life expectancy and maintenance-free
Over-voltage protection

Size and weight

Thermal Actuator

Nominal size (closed)

W178" [48.4 mm]
L8′ [2438 mm]
H2" [38 mm]

With VA10 adapter (closed)
H 2 316" (55.2 mm)

With VA10 adapter (opened)
H 2 316" (55.2 mm)
H +14" (7 mm)

0.27 lbs (123 g) with connection cable

Table Header
Valve adapter
VA 10 spacer ring (M30x1.5) (included with the product)
Color and finishing
Light gray (RAL 7035)
Thermal Actuator

Power cable

Pop-up blue ring
status indicator

Thermal actuator
Disconnect button

Ring valve adapter
VA 10 (M30x1.5)

Table Header
Operating voltage
24V AC/DC, +20%...-10%, 0-60Hz
Electrical connection
20 AWG (0.75 mm2) 2 conductors, blue (0 V) and brown (24 V) with 5 ft gray cable
Operating power
1 W (to maintain the valve open)
Max. inrush current
< 300 mA during max. 2 min. (Max power 6W)
Max temperature
200 °F @ 40 psi [90 °C @ 3 bar]
Voltage surge strength
15 - 60 psi [1-4 bar]2.5 kV (according to EN 60730)
14″ (7.0 mm)
Actuation force
100 N +5%
Closing and opening times
Approximately 3 minutes
Fluid temperature range
36 °F to 210 °F (2 °C to +100 °C)
Flow gauge range:
0 to 1.32 gpm [0 to 5 l/min] with marks every 0.25 gpm [1 l/min]
Storage temperature
0 °F to 140 °F (-18 °C to 60 °C)
Operating temperature
32 °F to 140 °F (0 °C to +60 °C)
Min. height clearances
2 12 (65 mm)
Ingress protection
IP 54 (class III) in all installation positions (equivalent to Nema 3s)
Size (LxWxH): 3" x 2" x 312 (75x50x90 mm)
Weight: 0.3 lb (140 g)
Instruction are printed inside the box
Size, weights and technical characteristics may vary without prior notice.

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