HFT40020Z-01 Thermostatic Valve
The Legom HFT40020Z-01 Thermostatic Valve is a G3/4 thermostatic mixing valve featuring a union water inlet connection and a distinctive numbered 1–7 MAX scale handwheel that allows the operator to set and record the mixed water temperature position by reference number rather than by thermometer reading alone. Built on the same thermostatic mixing platform as the wider HFT series — temperature adjustment range 20–60°C, control accuracy ±2°C, working pressure range 0.03–1 MPa — the HFT40020Z-01 adds practical usability improvements that benefit installers and maintenance personnel in commercial and domestic hot water applications.
The union inlet joint allows the valve to be disconnected from the water supply line without rotating the full valve body, simplifying installation in confined spaces and enabling faster cartridge access during servicing. Manufactured from 57-3 copper with nickel plating, compatible with hot water inlet temperatures of 30–99°C and cold water inlet of 5–29°C. Factory-preset temperature ranges available for OEM orders.
Key Benefits
- Numbered 1–7 MAX scale handwheel – The handwheel displays a numbered scale from 1 to 7 MAX rather than an unmarked dial, allowing the set temperature position to be recorded and reproduced precisely during commissioning, maintenance, or after a reset — eliminating the need to re-measure outlet temperature after every servicing event
- Union water inlet joint – The union inlet connection allows the valve to be disconnected from the water supply without rotating the full valve body, reducing installation time in confined spaces and enabling faster, cleaner cartridge access during periodic servicing
- G3/4 connection — standard domestic size – The most common water heater outlet connection size, compatible with standard domestic and light commercial hot water pipework and fittings
- ±2°C temperature control accuracy – Consistent mixed water delivery within ±2°C of the set point across varying supply pressure and temperature conditions
- 20–60°C adjustment range – Full range available across the 1–7 MAX scale, with factory-preset narrower ranges available for safety-restricted applications
- No electricity required – Self-acting thermostatic operation with no electrical connection needed at the valve
- 57-3 copper with nickel plating – Corrosion-resistant body for durable potable hot water service
- Wide pressure range 0.03–1 MPa – Suitable from low-pressure gravity-fed through standard mains-pressure water supply systems
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | HFT40020Z-01 |
| Body Material | 57-3 copper, nickel plated |
| Handwheel | ABS black silk-screen, numbered 1–7 MAX scale |
| Connection | G3/4 internal thread |
| Inlet Joint Type | Union water inlet joint |
| Temperature Adjustment Range | 20–60°C (standard); 35–55°C / 40–50°C / 30–60°C (preset options) |
| Temperature Control Accuracy | ± 2°C |
| Working Pressure Range | 0.03 MPa – 1 MPa |
| Ideal Working Pressure | 0.1 MPa – 0.5 MPa |
| Cold Water Temperature Range | 5°C – 29°C |
| Hot Water Temperature Range | 30°C – 99°C |
| Primary Use | Water heater (domestic and light commercial) |
HFT40020Z-01 vs HFT30001 G3/4 — Feature Comparison
| Feature | HFT40020Z-01 | HFT30001 G3/4 |
|---|---|---|
| Handwheel scale | Numbered 1–7 MAX | Plain / unmarked |
| Inlet joint | Union | Standard thread |
| Connection | G3/4 | G3/4 |
| Body finish | Nickel plated | Nickel plated |
| Temperature specs | Identical — same accuracy, range, pressure | |
Application & Use Cases
- Domestic water heater installations requiring repeatable temperature settings – The 1–7 MAX numbered scale allows the set position to be recorded in service documentation and reproduced exactly at the next maintenance visit, without requiring a thermometer to verify the setting before leaving site
- Managed properties and rental accommodation – Property managers can document the handwheel position setting as part of the installation record, enabling consistent reproduction of the commissioned temperature after any maintenance or cartridge replacement
- Solar thermal water heating systems – Where the handwheel may be adjusted seasonally or after maintenance, the numbered scale allows the correct setting to be restored quickly and accurately
- Care home and assisted living domestic hot water – Where the preset temperature setting must be verifiable and reproducible as part of Legionella risk management and safe water temperature compliance records
- Light commercial water heater outlets – Small offices, guesthouses, and bed-and-breakfast accommodation where G3/4 connection capacity is sufficient and the numbered scale simplifies training and handover documentation
Installation Notes
- Connect hot water supply to the hot inlet union (H), cold water supply to the cold inlet (C), and mixed water outlet (M) to the distribution pipework. The union inlet allows the hot supply to be disconnected without rotating the valve body
- Tighten union nuts hand-tight plus a quarter turn — do not overtighten, which can deform the union washer and cause leakage
- Install isolation valves upstream of both hot and cold inlets to enable full valve servicing without shutting down the water supply
- Install a strainer on the cold inlet to protect the thermostatic cartridge from debris
- After installation, set the handwheel to the desired position on the 1–7 MAX scale, run hot water from the furthest fixture, and verify outlet temperature with a calibrated thermometer. Record the scale position and corresponding measured temperature in the installation documentation
- The valve performs optimally at 0.1–0.5 MPa
Frequently Asked Questions
What does the 1–7 MAX scale on the handwheel represent?
The numbered scale divides the handwheel’s full adjustment range into seven reference positions, with 1 representing the lower end of the temperature range and 7 MAX representing the upper limit. The scale allows the commissioning engineer to set the valve to a specific numbered position, measure and record the actual outlet temperature corresponding to that position, and reproduce the exact setting at any future service visit by returning the handwheel to the same number. This is particularly useful when the valve must be removed for cartridge replacement — the replacement valve can be set to the same scale position and the commissioning temperature is immediately reproduced without re-measurement.
Why does the union inlet make servicing easier?
The union inlet joint allows the hot water supply connection to be broken and re-made without rotating the valve body — you simply loosen the union nut, which can be done in any orientation without needing clearance to spin the entire valve. This is particularly useful in tight under-sink or behind-panel installations where there is insufficient clearance to rotate the valve body, and in situations where the cartridge must be accessed for cleaning or replacement without fully removing the valve from service.
Can the temperature range be factory-preset?
Yes. OEM and project orders can specify factory-preset temperature ranges of 35–55°C, 40–50°C, or 30–60°C that mechanically restrict handwheel travel within the 1–7 scale. Contact the Legom team to specify the required preset range when ordering.
OEM & ODM Customization
Legom supports OEM and ODM services for the HFT40020Z-01 Thermostatic Valve. Customization options include preset temperature range, scale markings, connection size, body finish, and handwheel design. Contact us via WhatsApp or info@legomsmart.com.
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.
