910075NT Horizontal Thermostatic Mixing Valve
The Legom 910075NT Horizontal Thermostatic Mixing Valve is an inline mixing valve that automatically blends hot and cold water to deliver a constant outlet temperature, using an internal thermal element to continuously adjust the mixing ratio with no electrical connection required. Available in four temperature variants covering 20–43°C, 20–55°C, 35–60°C, and 30–70°C, the 910075NT suits both domestic hot water anti-scald applications and underfloor heating supply control. The pull-and-turn handle sets the target temperature and presses down to lock, preventing accidental adjustment after commissioning.
Built around a brass valve body with a Stainless Steel 304 spring, EPDM rubber seals, a copper thermal element, and a nylon internal cartridge, the 910075NT connects via G1″ external thread and delivers a flow capacity of KVS 2.5 m³/h. It maintains temperature control accuracy of ±3°C across a wide working range, operating from low-pressure gravity systems (0.2 bar) up to 5 bar mains pressure, with a 10 bar maximum static rating. A built-in anti-scald function shuts off the hot water inlet completely if the supply temperature spikes, resuming normal operation once conditions stabilise.
Key Benefits
- Temperature lock to prevent misoperation – After the target temperature is set, the handle presses down to mechanically lock the setting, stopping users from accidentally changing the outlet temperature in shared or public installations
- Anti-scald overheat shutoff – If the incoming water temperature spikes abruptly, the valve fully closes the hot water inlet as a fail-safe and automatically resumes mixing once the temperature stabilises, protecting users, floor heating pipes, and flooring from scalding or heat damage
- Four temperature range variants – Model options of 20–43°C, 20–55°C, 35–60°C, and 30–70°C allow the valve to be matched to the application, from low-temperature underfloor heating loops to higher-temperature domestic hot water delivery
- No electricity required – Fully self-acting thermostatic operation driven by the differential temperature of the hot and cold supplies, with no sensor, controller, or power connection needed
- Durable brass and stainless construction – Brass valve body and cover, Stainless Steel 304 spring, EPDM seals, and a copper thermal element provide corrosion resistance, anti-scaling, and anti-wear performance for long service life
- Wide working pressure range – Operates on both high-pressure systems (1–5 bar) and low-pressure gravity-fed systems (0.2–1 bar), with a 10 bar maximum static pressure rating
- High flow capacity of KVS 2.5 m³/h – A generous flow coefficient supports both single-fixture and central distribution duties without excessive pressure drop
- Suitable for hot water and floor heating – A single valve platform serves domestic hot water anti-scald outlets and constant-temperature underfloor heating supply, simplifying specification across project types
Model Variants
| Model | Temperature Range | KVS Value | Connection |
|---|---|---|---|
| 910075NT-1 | 20–43°C | 2.5 m³/h | G1″ external thread |
| 910075NT-2 | 20–55°C | 2.5 m³/h | G1″ external thread |
| 910075NT-3 | 35–60°C | 2.5 m³/h | G1″ external thread |
| 910075NT-4 | 30–70°C | 2.5 m³/h | G1″ external thread |
Technical Specifications
| Parameter | Specification |
|---|---|
| Model Series | 910075NT (variants -1 / -2 / -3 / -4) |
| Valve Body Material | Brass |
| Spring | Stainless Steel 304 |
| Seals | EPDM Rubber |
| Internal Cartridge | Nylon |
| Thermal Element | Copper |
| Adjustment Handle | Plastic, with temperature lock |
| Connection | G1″ external thread (3x) |
| KVS Value | 2.5 m³/h (max) |
| Temperature Control Accuracy | ± 3°C |
| Factory Temperature Setting | 20°C / 35°C |
| Mixing Water Temperature Range | 20–43°C / 35–60°C |
| Cold Water Temperature | 5°C – 15°C |
| Hot Water Temperature | 55°C – 75°C |
| Flow Pressure (High Pressure) | 1 – 5 bar |
| Flow Pressure (Low Pressure) | 0.2 – 1 bar |
| Maximum Static Pressure | 10 bar |
| Dimensions | 70mm width, Ø40 body, Ø39.2 handwheel, 101.6mm height |
| Primary Use | Domestic hot water systems, underfloor heating systems |
Application & Use Cases
- Underfloor heating supply control – Maintains a constant, lower supply temperature to underfloor heating loops, protecting heating pipes and floor finishes from high-temperature damage while keeping room comfort stable. The 20–43°C and 20–55°C variants are well suited to this duty
- Domestic hot water anti-scald protection – Installed at the water heater outlet or central distribution point to cap delivered hot water temperature, preventing scalding at showers, baths, and basins regardless of storage tank temperature
- Storage water heater outlets with heat trap – Installed downstream of a domestic hot water storage tank using a heat trap to prevent thermosiphon overheating during non-draw periods, holding outlet temperature at the set point
- Low-pressure gravity-fed systems – The 0.2 bar minimum low-pressure rating allows operation in gravity-fed hot water systems found in older buildings and rural installations without mains pressure
- Facilities requiring locked temperature control – The press-to-lock handle suits homes, apartments, and accommodation facilities where a fixed, tamper-resistant outlet temperature must be maintained for all users
Installation Notes
- Flush all supply pipework before installation to clear debris that could enter the valve and damage the thermal cartridge
- Connect according to the body markings: the red end is the hot water inlet, the blue end is the cold water inlet, and the arrow points to the mixed water outlet
- The G1″ external thread connections require matching female-threaded fittings on the supply and outlet pipes. Apply appropriate thread sealant and do not over-tighten, as excessive force can cause damage or leakage
- To set the temperature, pull the handle upward, then turn the adjustment cover counterclockwise to increase the outlet temperature or clockwise to decrease it. Press the handle down to lock the setting once complete
- Allow the system to stabilise for at least 1 minute after each adjustment, then verify the outlet temperature with a thermometer at a downstream fixture
- Ensure the minimum mixed water flow rate is met. Below the minimum flow, outlet temperature will drop and become unstable
- When installed downstream of a hot water storage tank, fit a heat trap with a vertical drop of roughly 20–30 cm and a horizontal clearance of 50–60 cm between the trap and the valve to prevent overheating from tank circulation during non-draw periods
- Install the valve in an accessible location for commissioning and future maintenance. Installation must be carried out by qualified, licensed personnel in compliance with local regulations, as incorrect installation can result in burns or serious injury
Frequently Asked Questions
What is the difference between a horizontal and a vertical thermostatic mixing valve?
The thermostatic mixing function is the same in both: an internal thermal element blends hot and cold water to deliver a constant outlet temperature. The difference is the body geometry and connection layout. The horizontal 910075NT has inline hot, cold, and mixed ports arranged for installation along a horizontal pipe run, which suits underfloor heating manifolds and inline domestic hot water distribution. The choice between horizontal and vertical depends on the available pipe routing at the installation point.
How does the temperature lock work?
After you pull the handle up and rotate it to the target temperature, you press the handle down to lock it in position. This mechanically prevents the setting from being changed by accident or by users who should not be adjusting it. To change the temperature again, pull the handle back up, set the new value, and press down to relock. This is particularly useful in shared installations where a fixed, tamper-resistant outlet temperature is required.
Can the 910075NT be used for underfloor heating?
Yes. The valve is widely used in underfloor heating systems to hold a constant, lower supply temperature to the heating loops, which protects both the pipes and the floor finish from high-temperature damage. The 910075NT-1 (20–43°C) and 910075NT-2 (20–55°C) variants cover the typical underfloor heating supply range, while the higher-range variants suit domestic hot water duties.
What happens if the hot water temperature suddenly spikes?
The valve includes an anti-scald overheat function. If the incoming water temperature rises abruptly, the valve fully closes the hot water inlet as a fail-safe, stopping overheated water from reaching the outlet. Normal mixing resumes automatically once the supply temperature stabilises. This protects users from scalding and protects floor heating pipes and flooring from heat damage.
Which model variant should I choose?
Select the variant by the temperature range your application needs. The 910075NT-1 (20–43°C) suits low-temperature underfloor heating, the 910075NT-2 (20–55°C) covers general underfloor heating and tempered hot water, the 910075NT-3 (35–60°C) suits standard domestic hot water anti-scald delivery, and the 910075NT-4 (30–70°C) covers higher-temperature applications. All four share the same G1″ connection and KVS 2.5 m³/h flow capacity. Contact the Legom team if you are unsure which range fits your system.
Why is a heat trap needed downstream of a storage tank?
When the valve is installed downstream of a hot water storage tank, hot water can circulate by natural thermosiphon during periods when no water is being drawn, gradually overheating the valve and the pipework near it. A heat trap, formed by a short vertical drop and horizontal offset in the pipe run, breaks this circulation and keeps the valve at the correct working temperature. Maintain roughly 20–30 cm of vertical drop and 50–60 cm of clearance between the trap and the valve.
What maintenance does the 910075NT require?
The valve uses EPDM seals, a Stainless Steel 304 spring, and a copper thermal element for anti-scaling and anti-wear performance, but periodic inspection is still recommended. In hard water areas, scale can build up on the internal cartridge and reduce temperature accuracy or cause the handle to stick. If the outlet temperature becomes inconsistent or the handle becomes stiff, the cartridge may need descaling or replacement. Contact the Legom team for cartridge and component specifications.
OEM & ODM Customization
Legom supports OEM and ODM services for the 910075NT Horizontal Thermostatic Mixing Valve. Customization options include temperature range and factory setting, connection size and thread type, body finish, and handle design. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
Datasheet
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
Custom OEM & ODM Solutions
Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
