Thermostatic mixing valves help control water temperature at taps, showers, baths, and wash hand basins.
They blend hot and cold water so the outlet temperature stays safe for daily use. This helps prevent scalding while still allowing hot water systems to run at temperatures that support legionella control.
Comfort Services Group provides professional TMV servicing, testing, and maintenance for commercial properties, healthcare facilities, social care settings, schools, offices, and public buildings. Our experienced technicians check that each valve is working correctly, operating safely, and meeting the regulatory standards required across the UK.
Protect Your Building & Remain Compliant-Book Your TMV Service Today
A faulty TMV can create a serious risk. Water may leave an outlet too hot, or the valve may fail to control the temperature as it should. Poor maintenance can also affect water flow, water quality, and the lifespan of the components inside the valve.
Our team provides expert TMV servicing with clear records, practical guidance, and an obligation quote when needed.
We help you maintain safe water temperatures, support regulatory compliance, and protect the people who use your building every day.
Contact Our ExpertsWhy Regular TMV Maintenance is Essential?
Regular TMV maintenance is not just a box to tick. It is a key part of safe building management, especially where people may be more at risk from scalding. Thermostatic mixing valve TMVs must be checked, cleaned, and tested in line with manufacturer’s instructions and site risk levels.
Regular servicing helps identify wear, poor temperature control, blocked strainers, weak water flow, and failed components before they become bigger problems. It also supports your wider water system plan, including legionella control and water quality standards.
Scalding Prevention
TMVs are important because they reduce the risk of scalding at water outlets. They do this by blending hot water with cold water before it reaches the outlet. If a hot water supply is too strong, or a cold water supply drops, a working valve should react fast.
This matters in care homes, schools, hospitals, and healthcare settings where users may not move away quickly. Regular TMV servicing checks the outlet temperature and fail safe response, helping ensure safe temperature delivery at hand basins, showers, and baths.
Legionella Control
Hot water systems have to store water at a higher temperature to lower the risk of Legionella growth , but at the same time they need to deliver water to washbasins, showers and baths that’s safe for users to use. And that’s where thermostatic mixing valves (TMVs) step in to help.
A TMV allows the hot water to stay hot in the system while keeping the mixed temperature at the outlet under control. When we carry out servicing, we check the water temperature, water flow, isolation valves and any signs of poor maintenance that could be compromising safety or water quality.
Legal Compliance
Commercial landlords, employers, and duty holders must manage risks linked to hot and cold water systems. This includes scalding and Legionella risks. Regular TMV servicing helps show that your building is being maintained in line with regulatory requirements, HSE guidance, ACoP L8, and, where relevant, HTM 04-01.
Good records matter too. If there is an inspection, audit, or insurance review, clear servicing documents can support your position. They show that valves were tested, maintained, and checked by an experienced technician.
What Our Customers Say
“The team at Comfort Services Group were awesome when they carried out the Legionella Control works at our offices, they were very accommodating, Tom and the guys on site were a pleasure to work with. I would recommend the services of Comfort Services Group without reservation. Excellent First impressions with the Office Team, which was mirrored by the guys who did the work. Thanks guys.”
Michael Green
“I have had Comfort commissioning working on different projects for the companies i have worked for over the past 15 years. They have assisted in many difficult projects throughout the country. Andy and Lawrence have been very professional and helpful. i found their attitude, and pro-active approach to be of very high standard. i will always push to use them on future projects”
Chris Richards
“Comfort commissioning are a great company, they deliver great services and the team there are very helpful and efficient. They really do care about their customers and take a keen interest in ensuring a high level of customer service is maintained at all times.”
Gary Clatworthy
“Fantastic service from Comfort from start to finish. Very responsive, friendly, reliable and professional.”
Sarah
“Contacted Comfort Commissioning Services Ltd for advice about unusual deposits in the header tank of an open vented domestic heating system. Not core business for them, but one of their directors responded to me really quickly via email with some excellent free advice which was greatly appreciated. Very impressed.”
Pete Davies
Our Comprehensive Thermostatic Mixing Valve
Testing Process
Our thermostatic mixing valve servicing process is thorough, practical, and easy to follow.
We do not only take a quick temperature reading and leave. Each visit is built around safety, performance, and compliance.
01
Initial Inspection & Temperature Testing
The visit starts with an inspection of the TMV, outlet, pipework, and surrounding components. Our engineer checks the hot and cold water supplies, water flow, isolation valves, and any visible signs of damage or poor maintenance.
We then test the outlet temperature and compare it with the required safe temperature for that setting. The fail safe function is also checked where possible. This confirms whether the valve can shut down or reduce flow if the cold water supply is interrupted.
02
Descaling & Cleaning
Limescale, dirt, and small debris can stop a valve from operating correctly. This is common in busy buildings and areas with harder water. During TMV servicing, the valve may be dismantled so internal components can be inspected, cleaned, and descaled.
This step helps restore smooth blending of hot and cold water. It can also extend the lifespan of the valve and reduce the chance of future faults. For example, a blocked strainer may seem minor, but it can affect outlet temperature and water flow.
03
Disinfection & Re-commissioning
After cleaning, the valve components are disinfected as needed and reassembled with care. The engineer then recommissions the TMV, adjusts the outlet temperature, and checks the valve again under working conditions.
This stage is important because a valve must be safe after servicing, not just clean. The engineer confirms that the TMV works as expected, supports safe water temperatures, and meets the site’s safety needs. In healthcare facilities, this step may also support HTM 04-01 compliance.
04
Digital Asset Logging & Certification
Once testing is complete, we record the results clearly. This includes details such as asset location, outlet temperature, valve condition, servicing actions, and any recommendations for repair, replacement, or more frequent servicing.
Digital asset logging gives facility managers and health and safety teams a clear record for their compliance logbook. It also makes future maintenance easier. If a valve has a history of failure, wear, or unstable temperature, the record helps identify the pattern before it becomes a larger risk.
Sectors We Serve
Comfort Services Group supports organisations across the UK that need reliable TMV maintenance and water hygiene support. Our work is suited to buildings where safety, documentation, and compliance cannot be left to chance.
We understand that different sites have different risks. A hotel, for example, may have many showers and baths used daily, while a care home may support people who are more vulnerable to scalding.
We take into account 4 key factors when it comes to our servicing approach:
the setting, the water system, the regulatory requirements, and above all user safety.
Healthcare facilities, hospitals, and NHS trusts
These sites have got to have strict control of water temperature and detailed records or else they won’t meet HTM 04-01 compliance. That’s why we service thermostatic mixing valves in clinical areas, patient rooms, wash hand basins, showers and other water outlets where the safe temperature control is mission critical for people with reduced mobility or heightened sensitivity to hot water.
Care homes and assisted living facilities
Social care settings really depend on having dependable thermostatic mixing valves, because residents may have reduced movement, slower reactions or higher sensitivity to hot water, so regular servicing is a must to prevent scalding, keep legionella under control and maintain water quality standards across the whole building, whether its private or shared areas.
Schools,
nurseries, and universities
Educational sites need safe water temperatures for all pupils, staff and visitors, so TMVs are often fitted on hand basins, changing rooms, showers and accessible facilities. Regular maintenance is a no-brainer to ensure that the systems stay safe, suitable and ready to use day in day out without any avoidable disruption.
Commercial offices, hotels, and public buildings
Busy commercial buildings rely on their hot and cold water systems working like clockwork every single day and we’re here to support landlords, facilities teams and building managers to maintain safe outlets, meet regulatory standards and keep clear servicing records for audits, insurance checks and planned maintenance reviews.
Need to Schedule Your Annual TMV Testing?
If your TMVs haven’t been checked in the last 12 months then it’s high time to get in touch. Regular TMV servicing keeps you safe, means you’re on top of regulatory requirements and reduces the risk of an unexpected valve failure.
At Comfort Services Group we can inspect, test, service and document your thermostatic mixing valves with minimal disruption to your site. We can also offer expert advice if a valve needs replacing, if servicing needs to be more frequent or if your current setup no longer meets the required standards.
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Frequently Asked Questions
How often should TMVs be serviced and tested?
This depends on the building and the level of risk. Care homes, nursing homes, and similar facilities typically test TMVs every six months, while many other premises carry out testing annually. Your risk assessment and the manufacturer’s guidance should determine the final schedule.
What is the difference between a TMV2 and a TMV3 valve?
A TMV2 valve is usually used in domestic properties and standard commercial settings. It is designed to control outlet temperature safely where the risk level is lower. A TMV3 valve is built for stricter healthcare settings and must meet higher performance standards.
TMV3 valves are often required in hospitals, NHS trusts, care environments, and areas covered by HTM 04-01. They are designed to protect highly vulnerable people where the risk of scalding must be managed very carefully.
What happens if a Thermostatic Mixing Valve fails a test?
If a thermostatic mixing valve fails either a temperature test or a fail safe test then it’s possible the outlet water might not be safe. The water could end up being too hot, too cold or just plain unstable. That in itself increases the risk of someone getting scalded or causes problems with the safe running of the water system.
Our engineer will try to figure out what’s gone wrong. This can involve getting the valve cleaned, descaled, adjusting any worn bits or even replacing them if need be. If, however, the valve can’t be repaired in a way that’s safe then we’ll recommend a suitable replacement to get the compliance and safety back on track.
Is TMV servicing required by law for commercial landlords?
Commercial landlords and employers have a legal duty to manage risks linked to hot and cold water systems. This includes risks from Legionella and scalding. Regular TMV maintenance is one way to help meet that duty and prove that reasonable steps have been taken.
ACoP L8, HSE guidance, and health and safety law all place responsibility on duty holders. Servicing records, temperature logs, and repair notes help show that your building is being managed properly.
