The Inta Intamix Thermostatic Mixing Valve is a single-outlet TMV designed to deliver safe, temperature-stable hot water to taps, showers, bidets and other outlets. Approved to both TMV2 (BS EN 1111 & BS EN 1287:2017) and TMV3 (NHS Estate D08 & BS 7942:2011), it is equally suited to domestic bathrooms and to hospitals, schools and leisure centres where scald-prevention compliance is mandatory. The valve holds mixed water temperature to within ±2°C across a 30°C to 50°C adjustment range, and its one-piece thermostatic cartridge means the entire working element can be serviced or replaced without removing the valve body from the pipework.
±2°C
Temperature Stability
10 Bar
Max Static Pressure
15mm / 22mm
Sizes Available
Important: Failsafe Cold-Water Shut-Off
To achieve the cold-water failsafe function, a minimum temperature differential of 10°C between the hot inlet and mixed outlet must be maintained. If the cold supply fails or the differential drops below this threshold, the valve shuts off the hot supply to prevent scalding — this is a core requirement of both the TMV2 and TMV3 schemes and must not be bypassed during commissioning.
Please Note: Maximum Pressure Differential
The maximum permissible pressure differential between the hot and cold inlets is 5:1. Installations with unbalanced supplies exceeding this ratio (e.g. mains cold with a low-pressure gravity hot feed) will affect the valve's ability to maintain a stable mixed temperature and may trigger nuisance failsafe shut-off.
Good to Know: Washers Supplied by Size
Each valve ships with 2x EPDM rubber sealing washers to ensure a watertight connection at the unions — 3/4" washers are supplied with the 15mm valve (40015CP) and 1" washers with the 22mm valve (40022CP).
Proportional Thermostatic Element
The internal element continuously balances the hot and cold inlet flows in proportion to one another, so the mixed outlet temperature is actively corrected rather than passively blended — this is what delivers the tight ±2°C stability figure.
One-Piece Cartridge Design
The thermostatic element, seals and non-return function are combined into a single replaceable cartridge, so routine servicing or element replacement does not require disturbing the surrounding pipework.
Integral Check Valves & Strainers
Built-in check valves prevent cross-flow contamination between the hot and cold supplies, while integral strainers protect the cartridge from debris — both are standard fittings rather than optional extras.
Dual TMV2 & TMV3 Approval
Independently tested and certified to NSF and approved under both the TMV3 scheme (NHS Estate D08, BS 7942:2011) and the TMV2 scheme (BS EN 1111 & BS EN 1287:2017), the same valve covers domestic, care and healthcare-grade installations.
Anti-Tamper Proof Head
The temperature adjustment head is anti-tamper by design, protecting the set temperature from accidental or unauthorised adjustment once commissioned — important in shared, public or care-setting installations.
Scale-Resistant Construction
The valve body and internal components are engineered to be highly resistant to limescale build-up, helping preserve stable performance in the UK's typically hard-water regions over the valve's service life.
| General |
| Brand |
Inta |
| Product Range |
Intamix |
| Type |
Thermostatic Mixing Valve (TMV) |
| Application |
Single outlet - taps, showers, bidets |
| Material |
Brass body, chrome plated finish |
| Lockable Adjustment |
Anti-tamper proof head |
| Performance |
| Temperature Adjustment Range |
30°C to 50°C |
| Temperature Stability |
±2°C |
| Max. Inlet Temperature |
85°C |
| Max. Static Inlet Pressure |
10 bar |
| Min. Dynamic Inlet Pressure |
0.2 bar |
| Max. Pressure Differential (Hot:Cold) |
5:1 |
| Min. Temperature Differential for Failsafe |
10°C (between hot inlet & mixed outlet) |
| Approvals & Compliance |
| TMV3 Scheme |
Approved - NHS Estate D08 & BS 7942:2011 |
| TMV2 Scheme |
Approved - BS EN 1111 & BS EN 1287:2017 |
| Building Regulations |
Part G compliant |
| Water Regulations |
WRAS approved |
| Included / Fittings |
| Check Valves |
Integral, both inlets |
| Strainers |
Integral, both inlets |
| Sealing Washers (15mm/40015CP) |
2x EPDM rubber, 3/4" |
| Sealing Washers (22mm/40022CP) |
2x EPDM rubber, 1" |
| MPN |
Size |
EAN |
Connection Thread |
| 40015CP |
15mm |
5055743501265 |
3/4" union |
| 40022CP |
22mm |
5055143700046 |
1" union |
What is the difference between TMV2 and TMV3 approval?
TMV2 (BS EN 1111 & BS EN 1287:2017) is the general low-pressure scheme used for most domestic and commercial installations. TMV3 (NHS Estate D08 & BS 7942:2011) is the more stringent healthcare-grade scheme required in hospitals, care homes and other settings where vulnerable users are at higher scald risk. The Intamix is independently certified to both, so the same valve can be specified across domestic and care-establishment projects.
Can this valve be used with unequal hot and cold water pressures?
It can tolerate a pressure differential of up to 5:1 between the hot and cold inlets. Where the differential exceeds this — for example, a mains-fed cold supply paired with a low-pressure gravity hot feed — temperature stability and failsafe reliability may be affected, so pressure conditions should be checked before installation.
How do I set the outlet temperature?
The Intamix has an adjustment range of 30°C to 50°C, set via the anti-tamper head. Once commissioned to the required outlet temperature for the application, the tamper-resistant design prevents the setting being altered without the appropriate tool, which is particularly important in shared or public-access installations.
Does the valve need annual servicing?
Like all thermostatic mixing valves, periodic servicing is recommended to maintain compliance and performance, particularly in TMV3 healthcare applications where servicing intervals are typically mandated by the site's written scheme. The one-piece cartridge design means the thermostatic element can be replaced without removing the valve body from the pipework.
What sealing washers are included, and do I need to buy them separately?
Both sizes are supplied complete with the washers needed for a watertight union connection: the 15mm valve (40015CP) includes 2x 3/4" EPDM rubber washers, and the 22mm valve (40022CP) includes 2x 1" EPDM rubber washers. No separate purchase is required for standard installation.
Is this valve suitable for a system with only one outlet, or can it serve multiple taps?
The Intamix is designed primarily for single outlet use — for example, one shower or one tap. For centralised or multi-outlet applications such as shower blocks, a higher-flow group mixing valve (such as the Intamix Pro range) is the appropriate specification instead.
