Thermostatic three-way valve Termojet 1" male thread, kvs-2.5, temp - 20-43°C

The Termojet TMV231 thermostatic three-way valve is a passive mixer with a built-in thermostatic element and an increased flow coefficient Kvs 2,5 m³/h. Connection GZ 1" (male thread), temperature maintenance range 20–43°C, accuracy ±2°C, maximum static pressure — 10 bar. The model is designed for larger underfloor heating circuits and systems with higher coolant flow rates — where Kvs 1,6 is insufficient.

Technical Specifications

Operating Principle

Hot water from the boiler and cold mains water enter through two separate inlets. The thermostatic element in the body responds to the actual temperature of the mixed water at the outlet — mechanically shifting the shutter and restoring the set temperature without electronics or automation. Maintenance accuracy is within ±2°C of the set value. Scald protection: if cold water supply fails, the valve automatically blocks the hot flow — water at a dangerous temperature will not reach the consumer. The locking cap prevents unauthorised adjustment of the set value.

Applications

• Large underfloor heating circuits. Kvs 2,5 handles the coolant flow for a floor circuit of up to 100–120 m² and more — where Kvs 1,6 creates excessive hydraulic resistance.
• Multiple DHW draw-off points. When shower and kitchen are used simultaneously, total flow increases — Kvs 2,5 ensures stable temperature without pressure drop.
• Commercial and hotel systems. Centralised hot water preparation with scald protection at several mixing points.
• Solar systems with a large collector. Protection against overheated water during active solar irradiation — the valve meters the exact share of hot flow.
• DHW recirculation circuits. Maintaining a safe and hygienically adequate temperature in systems with continuous circulation.

Advantages of the Termojet TMV231

• Increased Kvs 2,5 with the same GZ 1" thread — greater flow capacity without increasing installation dimensions.
• Brass body CW617N — corrosion resistance and long service life in systems with potable and process water.
• No power supply required — the passive thermostatic element maintains temperature around the clock without any running costs.
• Accuracy ±2°C — comfort and safety on a par with leading European equivalents in this class.
• Sealed cap — protection of the setting against unauthorised interference at facilities with enhanced security requirements.

TMV231 and the Heat Pump

A heat pump paired with underfloor heating of more than 100 m² requires a stable supply temperature in the range of 30–43°C. The Termojet TMV231 valve with Kvs 2,5 provides sufficient flow for large floor circuits and reliably protects them from temperature peaks in bivalent or transitional system operating modes. More about designing such systems — on the Termojet heat pumps website.

Frequently Asked Questions

How to choose between TMV131 (Kvs 1,6) and TMV231 (Kvs 2,5) with the same 1" thread?
Kvs 1,6 is sufficient for a single shower or underfloor heating circuit up to 60–70 m². Choose Kvs 2,5 when flow exceeds 1 m³/h — for large floor circuits, multiple draw-off points or commercial systems. Use the formula as a guide: Kvs ≥ Q / √ΔP (Q — flow in m³/h, ΔP — pressure differential in bar). For smaller sizes in the series — TMV121 GZ ¾" and TMV131 GZ 1" Kvs 1,6.

Can the TMV231 be used for DHW and underfloor heating simultaneously?
It is not recommended to connect a single valve to two different circuits with different pressures and consumption modes. The optimal solution is a separate TMV for DHW and a separate one for the floor circuit. This guarantees stable accuracy of ±2°C in each circuit independently of the others.