BRV Bonetti Rubinetterie Valduggia S.r.l.


Regolare e distribuire energia pulita

726 - Basic Series

Anti-scald thermostatic mixing valve for medium and small applications. Compact size. Available Kvs: 1.5, 1.8 and 3.4.

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ModvFresh Basic

Compact heat exchange unit to deliver fresh domestic hot water (DHW).

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Modular multi-zone distribution box for wall-mounted gas boilers or heat pumps. Three types of available pump units: direct, mixed motorized, mixed fixed point.

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Full bore 2-way zone ball valve, with bidirectional actuator with quick connection. Dimensions from 1/2" DN15 to 1"1/4 DN32.

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Multifunctional compact hydraulic module for the management of a direct circuit, a mixed circuit and the production of domestic hot water (DHW)

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DomvS Clima

Control unit for manifolds of heating and cooling radiant panels up to 200 m2. Fixed point thermostatic mixer or motorized rotary mixing valve. LCD room control unit.

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Mixing kit for ModvFresh Basic

35÷60°C thermostatic mixing kit designed for ModvFresh Basic, with anti-scald thermostatic mixing valve for small applications.

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°Caleon Thermostat - Wi-Fi

Elegant chrono-thermostat with TFT capacitive touch panel. Wi-Fi N 2.4 Ghz connection for remote control by °Caleon app.

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Technical part

Technical part:
Thermostatic Radiator Valves

How the TERMOSTAR valve works

The first operation performed by the valve is to take a 'reading' of the existing room temperature. A sensor fitted up  inside the adjustment knob is able to increase or reduce proportionally the rise or fall in temperature, recording even slight variations. It controls the valve working by closing or opening the valve lock. This system allows the complete exploitation of the heat produced independently from other heat sources such as the sun, other household electrical appliances, light sources and even the body heat emitted by people in the room. Therefore, the temperature set remains constant as the diagram below clearly shows.


How to use TERMOSTAR valve

Setting the required temperature is extremely simple. Turn the knob to coincide with the required value marked by the indicator. You must turn the selector switch clockwise to reduce the temperature and anticlockwise to increase it. The selector, which is marked with numbers 1-5, enables the reading of the value corresponding to the temperature set by means of the indicator. To enable maximum output both in terms of comfort and energy savings, the plumbing system should have devices suitable for Termostar working. The most important is a differential valve to restrict rises in pressure or a self-adjusting circulating pump; the use of a temperature delivery regulator that is sensitive to the various external temperatures is also recommended.

Installation and service

Directions for a correct installation

The sensor inside the knob reacts to the surrounding room temperature. For this reason the thermostatic valve should not be installed behind curtains, covers, forniture or in a niche. Direct exposure to sunlight or draughts is also to be avoided. The valve is supplied with a cap to protect it from damages during fitting and it also serves as manual control. The valve flow rate can be adjusted by turning the protection cap. 1K temperature variation corresponds to 52.8° cap rotation (2K=7 prominences). Installation should be carried out in accordance with the direction of the flow indicated on the valve body. However, the thermostatic head should be fitted in horizontal position, never vertically. Fitting of the thermostatic head can be facilitated by turning the knob to the maximum opening level (pos. 5) and making the four raised parts on the head coincide with the four notches on the valve body, and then screwing down the locknut.


Termostar requires no preventive service. However, replacement of the termostatic Kv-cartridge nut (in accordance with EN 215 requirements) may be necessary and it is sold as a spare part with relative O-ring.


Art. N°
Weight Gr.
750H - 755H
3/8" 1/2"

Technical Features

Head losses in the fixed model:


The liquid gas element has high sensitivity to the variations of temperature (0.3-0.4°C).


The amount of heat that 1 kilo of mass should yield so that the temperature will be reduced by 1K (For water the value is 4200).

[ kPa ] 
The pressure difference existing at the valve ends.
The temperature difference between the radiator entry and exit.
The difference in temperature between the set value and the heat sensitive element value.
kv [ m3 / h ] FLOW COEFFICIENT:
Flow rate in m3/h for a pressure drop across the valve of 1 bar.
The radiator's heating power in working conditions.
qm [ kg / h ] FLOW RATE:
The valve's flow rate with a determined differential pressure.

The ratio between the headloss of the thermostatic valve and the total headloss of the whole: valve+radiator+lockshield valve

Temperature setting range 6 – 28 °C
Response time of liquid gas element ~22 [Min]
0,34 [K]
Marking on temperature selector * - 5
Resolution 1 [°C]
Minimum setting temperature by
selector (Frost protection)
* (~6 [°C])
Locking device at any position
Setting range restriction minimum and maximun limitation available contemporaneously
Maximum torsion to the
temperature selector
according to EN 215
Maximum bending moment to the temperature selector according to EN 215
Storage temperature -20°C / +50°C. Within this range of temperature the physical features of the thermostatic head remain unchanged.
Maximum working temperature 120 [°C]
Maximum permissible
differential pressure
1 [bar]
Maximum permissible static pressure 10 [bar]
Effect of water temperature 0,45 [K]
Differential pressure influence 0,5 [K]
Calculated coeffcient "Variation Temporelle" 0,29 [K]
CA value 0,2 [K]
Spindle movement in mm/K 0,22 [mm/K]
Seat authority

Approximate ambient temperature


As stated by Norm EN 215, we declare as follows:

qm NH     190 Kg/h ± 10% for all models.
Nominal value of flow coefficient 'Kv': 0,60 m3/h

Art.       qm max Kv max
750H 3/8" 360 Kg/h ± 10% 1,14
750H 1/2" 370 Kg/h ± 10% 1,17
755H 3/8" 330 Kg/h ± 10% 1,04
755H 1/2" 370 Kg/h ± 10% 1,17

Qm NH is the theoretical flow rate obtained with the temperature of S - 2K point and with a 10 kPa (0.1 bar) differential pressure, as read from below diagram (the example is referred to Art. 755H 1/2"):

qms: 188 [ kg / h ] (-1%)

Besides, we define a as the seat authority in correspondance with nominal flow rate.
a is calculated as follows:

a = ( p1 - p2 ) / p1

p1 = 10 kPa differential pressure;
p2 = differential pressure in correspondence with nominal flow rate with valve fully open.

a = 0.72 ± 10% for all the models.


Here below picture of methodology carried out to define above diagrams:

Up-to-date 18/11/2020