TMV2 & TMV3 Certification
Thermostatic Mixing Valves (TMVs) play a critical role in controlling water temperature and preventing scalding risk in healthcare, residential and commercial environments.
TMV2 & TMV3 schemes define performance, safety and fail-safe requirements for these products, with specific application depending on installation environment and regulatory expectations.
These schemes are supported by recognised UK performance standards, including BS EN 1111 (high pressure systems) and BS EN 1287 (low pressure systems), which define functional requirements for thermostatic mixing valves.
For manufacturers, achieving TMV certification is not just a product test, it requires alignment across performance validation, product design, materials compliance and UK regulatory frameworks.
AquaCompliance supports manufacturers in structuring and managing TMV certification programmes, ensuring alignment with wider UK approval requirements and avoiding unnecessary duplication across testing and certification pathways.
What is TMV2 & TMV3?
TMV2 & TMV3 are UK certification schemes for thermostatic mixing valves, designed to ensure safe, stable and consistent control of water temperature across a range of installation environments.
The applicable scheme and performance classification are determined by the manufacturer based on intended use, installation environment and operating conditions, including pressure range.
Products are therefore assessed against the relevant scheme (TMV2 or TMV3) and supporting standards (e.g. BS EN 1111 or BS EN 1287) according to how and where they are designed to be installed.
- TMV2 — Applies to domestic and light commercial applications
- TMV3 — Applies to healthcare and higher-risk environments, including hospitals and care facilities
Both schemes are used to demonstrate compliance with temperature control and scald prevention requirements in UK installations
- BS EN 1111 — Thermostatic mixing valves for high pressure systems
- BS EN 1287 — Thermostatic mixing valves for low pressure systems
- TMV3 D08 — Scheme-specific performance and fail-safe testing requirements for healthcare environments
TMV3 certification includes more stringent performance criteria and testing protocols due to the higher risk environments in which it is applied.
Where TMV Applies
TMV certification is typically required for:
- Healthcare facilities (hospitals, care homes, clinics)
- Residential developments
- Hotels and hospitality environments
- Public buildings and commercial washrooms
- Education and leisure facilities
TMV3 is generally mandated where vulnerable users are present, while TMV2 is used across standard domestic and commercial installations.
Compliance & Approval Process
TMV certification typically involves a structured combination of product testing, technical review and certification body approval.
Key stages include:
- Definition of intended use and operating conditions (including pressure classification and application environment)
- Alignment with applicable performance standards (BS EN 1111 / BS EN 1287) and TMV3 scheme requirements (e.g. BuildCert D08)
- Submission of technical documentation and product data
- Laboratory testing against scheme-specific performance requirements
- Certification body review and approval
- Ongoing compliance requirements, which may include periodic sampling and audit testing during the certification cycle (typically 5 years), depending on certification body requirements
The process requires alignment between product design, intended application and supporting compliance data.
How AquaCompliance Supports
AquaCompliance provides structured support across the full TMV certification process:
- Regulatory Pathway Definition — Clarifying how TMV2 & TMV3 and BS 6920 requirements apply and identifying appropriate approval routes based on product type, designation, materials and intended application.
- Documentation Review — Review of available technical information and supporting data to identify potential gaps prior to testing or submission, including opportunities to leverage existing data where appropriate.
- Laboratory Coordination — Liaising with accredited laboratories to understand capability, capacity and resource availability, supporting realistic planning and alignment of project timelines.
- Certification Body Engagement — Supporting communication with WRAS and relevant certification bodies to help address queries and progress approvals.
- Commercial & Technical Alignment — Aligning TMV requirements with WRAS, BS 6920 and other UK approvals to streamline certification and reduce duplication
- Application & Project Management — Coordinating activities across internal teams, laboratories and stakeholders from assessment through to approval.
Key Considerations
- Alignment with BS 6920 testing requirements to support TMV material requirements
- Availability and suitability of existing test data
- Clear definition of intended application, pressure classification and certification pathway (TMV2 vs TMV3)
- Product range complexity, including variations in models, sizes and configurations
- Laboratory capability, capacity and lead times
- Alignment with applicable performance standards (BS EN 1111 / BS EN 1287) and scheme-specific requirements (TMV3 D08)
- Understanding of ongoing certification requirements, including potential audit testing and surveillance activities
Additional factors can significantly influence testing scope, timelines and overall project cost:
- Supply chain complexity — Multiple material and component suppliers, leading to increased coordination requirements, expanding testing scope, overall project cost and timelines
- Opportunities to leverage existing data — Existing approvals or test data may reduce duplication and support more efficient project delivery
- Definition of product application designations — Broader application claims can significantly increase testing scope, timelines and cost depending on product type (e.g. bath, shower, bidet, basin/tap)
- Gaps in documentation or material data — May lead to additional testing or clarification being requested
- Alignment of documentation across standards — Where accepted by certification bodies, this can support efficiency and reduce rework
Testing requirements are driven by product design, materials and intended application. These factors directly influence timelines, laboratory availability and overall project cost.
Early clarity supports efficient planning, reduces duplication and enables right-first-time delivery.Related Requirements
TMV certification form part of the wider UK water compliance framework and are often considered alongside additional requirements depending on product type and application.
Within the UK, TMV certification operates as an independent performance-based scheme, while BS 6920 testing is frequently required across multiple approval routes, including WRAS / REG4, particularly where material suitability is a key consideration.
- WRAS approval & BS 6920 testing — Covering product approval, mechanical performance and the suitability of materials for use in contact with drinking water
A coordinated, multi-standard approach enables manufacturers to streamline documentation, optimise testing strategies and efficiency across global certification pathways.
If you are planning product approval, reapproval or material changes, early clarity on requirements and approach can significantly improve timelines and outcomes.
AquaCompliance supports projects from initial assessment through to approval, helping identify gaps, streamline activities and maintain alignment throughout delivery.
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