• Controls valves by means of the 230VAC NC actuators
  • Control up to 12 zones

The Watts Master Control Unit has been specially designed to control underfloor heating by means of the normally closed actuators. Each control unit can control 6 zones and can be extended up to 10 or 12 zones by means of 4- or 6 zones slave modules.

  • Can be extended up to 10 or 12 zones
  • A maximum of 4 actuators per zone is advised
  • External antenna


Operating temperature: 0°C ~ 50°C
Regulation characteristics: Proportional Integral regulation with:
15 minutes cycle for 2°C
Anti-short cycle: 3 minutes OFF, 2 minutes ON
Supply voltage: 230VAC ±-10% 50Hz.

Pump or accessories: Relay => 5A / 250 VAC (free contact)
Actuators (Normally Closed) Relay => 5A / 230 VAC (L, N)
For easy installation we recommend a
maximum of 4 actuators per zone

Radio frequency: 868, 3 MHz, <10mW.
Range of approx. 180 meters in open space
Range of approx. 50 meters in residential

Certifications: EN 300220-1, -2
EN 301489-1, -3
Protection: IP30
Combination: 10 Zones => 1 Master 6 + 1 Slave 4 zones
12 Zones => 1 Master 6 + 1 Slave 6 zones

Watts Article number: 900004842


Watts Industries


Watts Industries are the leading innovators and manufacturers of thermostatic control systems for Underfloor Heating systems throughout the world. Watts thermostatic control systems have been developed to be easy to use and long lasting. Watts supply many leading companies throughout the world with thermostats including Floor Heating-Direct and Magnum Heating.

Watts Industries manufacture an extensive range of products dedicated to the comfort and safety in the area of water and heating, for domestic, commercial and industrial applications. Shop our range of Watts thermostats today. If you have any questions then get in touch and one of our specialist engineers will be on hand to answer any questions.


Buying Watts Thermostats and Control Units

  • Quick and easy ordering process, via website or telephone
  • Highest European approvals and certifications on all products ensuring quality & reliability
  • UK based technical support service, along with a full CAD design service ensures your total support along the whole design/purchase/installation process
  • Fast free delivery anywhere in the UK mainland
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