What is a Thermostatic Mixing Valve?
A thermostatic mixing valve (TMV) is a device that ensures the water temperature is at a safe and comfortable level which prevents people from scalding themselves. Hot and cold water is blended as it passes through the valve on its way to the tap, ensuring it is at a safe temperature by the time it reaches the water outlet.
Hot water sources such as hot water cylinders should be kept at a temperature of 60oC in order to prevent bacteria such as legionella from breeding. As such, these high temperatures may scald the skin. Therefore it is necessary to blend the hot and cold water to a temperature for safe use, particularly where vulnerable persons are present. This is especially important when it comes to accessible toilets and service user areas as some users are not able to move away from the water quickly enough to prevent scalding. Others may have conditions where they cannot physically feel any temperature changes.
Children and the elder are particularly at risk from scalding from hot water with statistics showing that nearly 600 people suffered serious scald injuries in the UK each year. And 75% of those scalded were children under five years of age. This is why TMV servicing is essential.
Scalding risk in temperatures
What temperature does scalding start for vulnerable people?
When it comes to scalding, the HSE states that – “There is a risk of scalding where the water temperature at the outlet is above 44°C. In certain facilities with ‘at risk’ patients this is especially so where there is whole body immersion in baths and showers of vulnerable patients, including the very young, elderly people, and people with disabilities or those with sensory loss who may not recognise high temperatures and respond quickly.” HSG 274 – p.2163
What temperature is scalding for most people?
“For most people, the scalding risk is minimal where water is delivered up to 50°C at hand wash basins and using hot water signs may be considered sufficient, where a TMV is not fitted. However, where vulnerable people are identified and have access to baths or showers and the scalding risk is considered significant, TMV Type 3 (TMV3) are required.” HSG 274 – p.2.164
What type of TMV and where?
“The use and fitting of TMVs should be informed by a comparative assessment of scalding risk versus the risk of infection from legionella. Where a risk assessment identifies the risk of scalding is insignificant, TMVs are not required. The most serious risk of scalding is where there is whole body immersion, such as with baths and showers, particularly for the very young and elderly, and TMVs should be fitted at these outlets. Where a risk assessment identifies a significant scalding risk is present, eg where there are very young, very elderly, infirm or significantly mentally or physically disabled people or those with sensory loss, fitting TMVs at appropriate outlets, such as hand washbasins and sinks, is required.” HSG 274 – p.275
Health care buildings
“Where a scalding risk is considered significant (eg where users are very young, very elderly, infirm or significantly mentally or physically disabled or those with sensory loss) then type 3 TMVs that are pre-set and fail-safe should be provided (but are required at healthcare premises) and should be checked regularly to ensure they are fail-safe if the cold water supply pressure is interrupted.” HSG 274 – infobox 2.3: Thermostatic mixing valves
“Where a scalding risk is assessed as low (eg where healthy users immerse their whole body), type 2 TMVs that can be overridden by the users are required by building regulations.” HSG 274 – infobox 2.3: Thermostatic mixing valves
What temperatures should a TMV be?
Set to 38-43°C
Showers and hair-wash facilities
Set to 41°C
Set to 41°C
Baths for assisted bathing
Set to 46°C
Set to 38°C
Note – bath fill temperature of more than 44°C should only be considered in exceptional circumstances where there are particular difficulties in achieving an adequate bathing temperature.
Temperatures as listed in – The HTM 04-01: Safe water in healthcare premises. Part A: Design, installation and commissioning practices (table 2 page 55)
How often do TMVs need servicing?
“Where the risk assessment considers fitting TMVs appropriate, the strainers or filters should be inspected, cleaned, descaled and disinfected annually or on a frequency defined by the risk assessment, taking account of any manufacturers’ recommendations.” HSG 274 – p.2.164
Get in touch to book your TMV servicing!
What is included in TMV servicing?
Review the installed TMV to ensure correct specification valve is installed where required.
Undertake temperature check and re-calibrate where required.
Ensure TMV failsafe mechanisms operate correctly to protect users in the event of water supply failure.
Clean, Descale & Disinfect
Clean, descale and disinfect any strainers or filters.
Get a Quote
To get a quote you can phone, email or complete our 'Get a Quote!' form to receive a quotation within 24 hours.
Book an Appointment
Once you're happy with your quote we'll confirm a suitable date and estimated time of arrival for your appointment.
An engineer will be with you on your scheduled date, and will call you prior to arrival (when safe and possible).
Report & Support
Our team will quality assess your report for PDF distribution, typically within 2-10 days of the site visit.
All payments are due prior to booking completion unless agreed in writing for 30 days from the date of invoice. We will hold your booking time for 24 hours whilst we wait for payment.
Your dedicated water hygiene team
Customer Service Manager
Water Hygiene Engineers
When and how often do I need a risk assessment?
Under the Health and Safety at Work Act 1974 and in compliance with the Approved Code of Practice (ACoP L8, HSG 274), duty holders, including employers and those in control of premises, must ensure the health and safety of their employees or others who may be affected by their undertaking, this includes the risk of legionella. Legionnaires Disease is a form of pneumonia, which can be fatal and the main route of infection is through inhalation, by inhaling airborne water droplets that contain Legionella. This also applies if you are a private Landlord and have rental properties which are occupied.
This includes taking suitable precautions to prevent, manage and control the risk of exposure to legionella. You can do this by undertaking the following: a risk assessment, actioning all identified risks within the initial report with remedial works, sampling the water quality to confirm bacterial presence with water testing, and carrying out ongoing record keeping also known as monitoring.
Do I need testing, a risk assessment or both?
Legionella testing, water testing or sampling is not to be confused with a legionella risk assessment. You are required by law to undertake a legionella risk assessment under the Health and Safety at Work Act 1974, COSHH and a number of other regulations where you can show you are working to comply with the HSE’s HSG 274 legionella guidelines.Testing or sampling whilst not a legal requirement on it’s own, it plays an important role in determining how efficient a water system is managed. Your risk assessment may identify that sampling is required due to existing risks or as a control and management precaution. In this instance sampling then becomes a requirement from your assessment. Without an L8 risk assessment you will not know where and how many samples are required. And without water testing/sampling you cannot determine how affective your control and management is. These two actions therefore should be undertaken together, not necessarily at the same time but unison to effectively management your risk from legionella.
Water testing services include Legionella, e-Coli, total viable count (TVC), Pseudomonas, hard water, chlorine free, pH levels and more. Learn more about legionella testing. We only use UKAS approved laboratories giving you peace of mind that the test will be of the highest quality possible.
How much does an L8 risk assessment cost?
All assessments vary in prices depending on the number of water outlets, cold water storage tanks, hot water cylinders, combi boilers and other water assets that may be present. The number of assets within your water system will determine the time spent on site and how long it will take to produce your report.
So how much does it cost? Across the industry, prices vary enormously often depending on the size of the company you use and their processes, the speed of works and professionalism. There are two types of assessments, the first is commercial and the second domestic, also referred to as residential rental properties or landlord risk assessments.
Commercial risk assessments normally start from £250 to in excess of £750, however our prices start from £99 depending on the size of the water system and location.
Domestic risk assessments can range tremendously with a number of plumbers, gas engineers and other tradesmen offering these assessments without the specialist training, it’s important to check that your assessor or engineer is properly qualified. Our prices start from £55 for multiple landlord properties to £95 for single landlord properties. Our prices for residential rental properties are based on the property being no more than 5 bedrooms.
How long will the risk assessment take?
On average, the time our qualified assessor spends on site is 1 hour for every 10 outlets (sinks, showers, baths, etc). So an assessment can take anywhere between 30 minutes to 6 or 7 hours. It entirely depends on the size of your water system and the number of water assets you have such as cold water storage tanks, cylinders or combination boilers.
Our engineers will work closely with you to ensure minimal disruption to your business is caused. Clear and easy access to rooms and buildings will play a part in time spent on site at your premises.
When will I receive your findings?
You will receive your LRA report between 2-10 working days from the date the assessment was carried out. From time to time, not often, our team will need a little more time, so please expect to have your report no later than 30 days. Need your assessment sooner? Get your report, guaranteed next day delivery via email for just £50.
What happens after I receive the report?
Within your report document, you will have an action plan offering guidance which lists all identified risks, with photos, that need remedying in order of importance. By following our advice and undertaking remedial works you will reduce the risk of exposure to Legionnaires’ disease. Once all the remedial works are complete, you will then need to focus on implementing your monitoring (periodical checks and maintenance) with a logbook for recording keeping all legal duties and monitoring requirements.
Are uRisk qualified?
Yes, all of our assessors are fully qualified and accredited by City & Guilds and can help assist you in meeting compliance today for HSE (ACoP L8). We are also Safe Contractor and Construction Online approved so you can rest assured that you are working with a trusted water hygiene service provider who put health and safety first.
All our engineers are DBS Checked to ensure suitable people are entering your premises and to safeguard vulnerable people. We are committed to maintaining the highest standards.
Do uRisk service my area?
Yes, our services are nationwide. Whether you have one or multiple water systems and one or multiple sites, we provide services across the country, with qualified engineers scattered throughout the UK and offices based in Hertfordshire which is a 30-minute train journey to London King’s Cross.
Why choose uRisk?
Over 25 years of water hygiene and legionella control experience.
Friendly and simple advice by phone, email & online at your convenience.
All staff are trained water hygiene consultants and engineers.
With engineers located all across the UK, we’re never too far away.
Our labs are UKAS approved providing you with quality assurance.
Your one stop shop for Legionella control, no need to go elsewhere.