Thermostatic Valves

Thermostatic Mixing Valves (TMVs) play a vital role in maintaining safe and stable water temperatures across domestic, commercial, and industrial hot water systems. By blending hot and cold water to a controlled temperature, they help protect users from scalding, support system efficiency, and ensure compliance with UK safety and water regulations.

At Pipestock, our range includes thermal balancing valves, 2-in-1 mixing valves, and advanced 4-in-1 service valves - each designed for reliable temperature control, long-term durability, and ease of maintenance. With WRAS, TMV2 and TMV3 approvals (model dependent), these valves offer dependable performance for washrooms, healthcare facilities, education buildings, commercial premises, and general hot water distribution systems.

A thermostatic mixing valve (TMV) is a safety device that blends hot and cold water to a pre-set, stable temperature before it reaches the tap or outlet. It automatically adjusts to changes in pressure or temperature on either supply line, ensuring the mixed water remains consistent and safe for users.

By preventing water from reaching scalding temperatures and maintaining reliable temperature control, TMVs are widely used in domestic hot water systems, commercial washrooms, care facilities, schools, and anywhere user protection is essential.

• Protect users by maintaining stable outlet temperatures
• Improve energy efficiency by regulating hot water distribution
• Support compliance with safety standards such as TMV2 and TMV3
• Suitable for a wide range of DHW (domestic hot water) applications
• Available with isolation features for easy servicing and system upkeep

Designed to optimise hot water circulation, this automatic thermal balancing valve ensures consistent temperatures throughout DHW systems. Its built-in temperature gauge provides at-a-glance visual monitoring, while the 70°C thermal disinfection function helps combat Legionella risk. Manufactured from high-quality DZR brass and WRAS approved, it is ideal for commercial and domestic recirculation loops.

Features

• Automatically regulates flow and temperature to maintain balanced DHW circulation
• Integrated temperature gauge for quick, accurate system checks
• Anti-Legionella activation at 70°C for thermal disinfection cycles
• High-grade DZR brass construction for corrosion resistance
• WRAS approved for potable water applications
• Available in 1/2", 3/4", and 1" BSP parallel threads

This compact 2-in-1 valve blends hot and cold water to a safe, stable outlet temperature, even with fluctuating supply pressures. Designed for both domestic and commercial installations, it offers precise control, strong outlet stability, and excellent corrosion resistance thanks to its DZR brass construction. TMV2, TMV3 and WRAS approvals make it suitable for environments where user protection and reliable temperature management are essential.

Features

• Thermostatically blends hot and cold water to a controlled temperature
• TMV2, TMV3 and WRAS approved for safety-critical washrooms
• Maintains ±2°C temperature accuracy under varying operating conditions
• Suitable for hot supplies up to 85°C and cold supplies down to 5°C
• Adjustable outlet temperature from 30°C to 48°C
• DZR brass body for long-term resistance to dezincification
• Compression end connections to BS EN 1254-2

Combining thermostatic mixing with integrated isolation valves, this 4-in-1 solution allows for quick servicing, maintenance, and system checks without the need for a full drain down. Offering the same safety, performance and approvals as the 2-in-1 model, it reduces installation time and improves operational efficiency - making it ideal for high-demand commercial systems and facilities requiring regular maintenance.

Features

• Integrated isolation valves for easy servicing and maintenance
• TMV2, TMV3 and WRAS approved for regulated applications
• Maintains stable outlet temperature within ±2°C
• Suitable for hot inlets up to 85°C and cold down to 5°C
• Adjustable mixed water temperature between 30°C and 48°C
• DZR brass body provides strong corrosion and dezincification resistance
• Compression connections to BS EN 1254-2

Adjusting a thermostatic mixing valve is a straightforward process, but it should always be carried out carefully to ensure safe and accurate temperature control. Although specific steps may vary slightly between manufacturers, the general procedure is as follows:

• Identify the adjustment mechanism
  • Most TMVs feature a removable cap or protective cover that conceals the temperature adjustment screw or dial
• Remove the cap
  • Gently lift or unscrew the cap to expose the adjustment point
  • Note: Some valves require a small tool or screwdriver
• Turn to adjust the temperature
  • Clockwise usually reduces the outlet temperature
  • Anticlockwise usually increases it
  • Make small adjustments - typically a quarter turn at a time
• Allow the temperature to stabilise
  • Run the tap or outlet for at least 30–60 seconds before re-measuring, as TMVs need a short settling period
• Check with a thermometer
  • Use a reliable digital thermometer at the outlet to confirm the new temperature. The recommended safe setting for most applications is around 38°C, depending on system requirements
• Replace the cap
  • Once the correct temperature is achieved, refit the protective cover to prevent accidental adjustment