Hydraulic balancing of a flow-meter manifold does not, by itself, create room-by-room temperature control. A thermostat, zone controller, electrothermal actuator and circulation pump must work as a coordinated system. Otherwise a circuit may respond in the wrong direction, a room may heat slowly, or the pump may continue to operate against closed zones. This guide focuses on electrical interfaces and commissioning, not manifold flow calculations.
1. Separate the thermostat, controller and actuator roles
A thermostat senses room temperature and issues heat demand. A zone wiring centre allocates the demand to suitable outputs. A thermal actuator gradually moves a manifold valve pin to open or close a water circuit. None of these functions automatically establishes hydraulic flow balance.
The ATLAS wired thermostat page describes an associated controller with eight outputs/eight zones. This does not mean one thermostat measures eight independent rooms. Specify the sensor and demand logic for every zone and the quantity of actuators per output.
2. NC versus NO and mechanical M30×1.5 checks
A normally closed (NC) actuator is designed to keep its associated valve closed when de-energised; a normally open (NO) version differs. Determine the actual valve-pin mechanics and the required power-loss state. These slow electrothermal elements are not equivalent to fast modulating 0–10 V rotary valve drives.
The ATLAS product page lists M30×1.5 threads, 100 N force, 4 mm travel, NC/NO variants and 24 V/230 V options. These details require confirmation for the order code. Matching the thread alone does not prove seating height, sufficient stroke or universal manifold compatibility.
3. Do not mix 24 V and 230 V circuits
Read the thermostat supply, wiring-centre supply and actuator output voltage independently. A 240 V AC thermostat specification does not imply that every connected actuator is a 230 V version. Check whether the output is a voltage-switched contact or a dry relay contact, and distinguish 24 VAC from 24 VDC.
Apply the manufacturer’s wiring drawing, protection requirements, relay ratings, wire sizing and separation of mains from extra-low-voltage circuits. Mains work beside wet pipework requires a qualified installer.
4. What should happen when the last zone closes?
All zones closed is a design condition for the circulation pump and heat source. If a controller provides a pump output, verify its signal type, allowable relay load and required pump overrun delay from the actual wiring diagram. The term “pump protection” alone is not proof of direct mains switching capability.
Review variable-speed pumping, differential-pressure behaviour, the minimum-flow route, bypass arrangements and boiler/heat-pump demand signalling together. A wrong sequence can create high differential pressure or starve the heat source of minimum flow.
5. Sizing example: six zones, two actuators each
In an illustrative six-zone layout with two actuators per zone, there are twelve electrical loads. Assume an example steady consumption of 2 W per actuator: steady power totals 24 W, equivalent to 1 A at 24 V or roughly 0.104 A at 230 V under ideal power-factor assumptions. These are not measured ATLAS product ratings.
Initial current and simultaneous energisation can exceed simple steady-state estimates. Determine the permissible actuators per channel and transformer/relay sizing from controller and actuator data sheets, with appropriate design margin.
6. Commission from heat demand to valve motion
Raise demand in one room only, then verify the correct controller LED/output, measured actuator voltage and physical valve response. The ATLAS product family notes an approximately 120-second response figure for a specified 230 V variant; never assume an instantaneous full stroke. Next verify pump and heat-source behaviour when all zones become satisfied.
EN 1264 addresses surface heating design and comfort constraints; a thermostat’s published 5–60 °C setting span does not mean every value is suitable for occupied rooms. Include restart, mains-loss, manual override and disconnected-cable tests in the handover report.
Frequently asked questions
Does an eight-zone controller need only one thermostat?
Not necessarily. Each room’s temperature signal and heat demand must be designed; eight outputs do not equal eight sensors in one thermostat.
Does M30×1.5 guarantee valve compatibility?
No. Pin geometry, closing dimension, stroke and force must also match.
Ask ATLAS to review your manifold loop count, room-to-zone matrix, thermostat model, supply voltage and pump control requirements.
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Electrical quantities and response times are variant-specific or illustrative; installation must follow verified schematics and qualified practice.