Closed System Testing

Closed System Testing | Heating System Analysis | Protect your Heating System

Closed System Testing Analysis


Regularly testing your closed heating or cooling system for microbiological and chemistry levels ensures your system is under control and is a preventative task that helps reduce risk of system failure, corrosion, scale, poor flow and bacterial growth. All of which can help reduce large bills to repair inevitable system failures if no testing is carried out. Such testing can help identify sufficient chemical inhibitor levels such as Molybdate and Nitrite. 

uRisk is a nationwide water hygiene company with City and Guilds trained engineers who have experience in industrial, commercial and domestic heating and cooling systems.

How often should I Test my Closed System?


Closed System Testing frequency is carried out every 3 months (quarterly) or when a system has changed where there is new or additional pipework.

How long does Closed System Testing take?


Closed System Testing can take up to 1 hour depending on the design and heating system you have installed.


What happens after the Closed System Testing Results


Once you receive you Closed System Testing Results you will be advised on the next steps to take. In most instances you will be advised to have your system dosed with either inhibitor and/or biocide. You may also be advised that further Closed System Testing is required to interpret how the inhibitor and/or biocide has impacted your system.

How much does Closed System Testing cost?


Closed System Testing prices may vary depending on the size, quantity of your systems and site requirements, but industry prices generally range between £100 to £400 per system test.

Microbiological Testing/Analysis

Aerobic Colony Count

Nitrite Reducing Bacteria (NRB)


Sulphite Reducing Bacteria (SRB)

Chemisty Testing/Analysis

Visual appearance

Suspended Solids

Phosphate as PO4

Alkalinity as CaCO3 (Automated)

Iron, Ferric (Filtered)

Calcium, Dissolved

Aluminium, Dissolved


Solids, Settleable

Nitrate as NO3

Ammoniacal Nitrogen as N

Boron, Dissolved

Copper, Dissolved

Iron, Dissolved


Silicate as SiO2


Iron, Total

Boron, Dissolved

Magnesium, Dissolved

Potassium, Dissolved

Total Dissolved Solids

Nitrite as N

Sulphate as SO4

Iron, Ferrous (Filtered)

Molybdenum, Dissolved

Zinc, Dissolved

Sodium, Dissolved

How to make my Heating System or Cooling System more Efficient?


New systems are often higher more efficient systems heating systems and cooling systems due to technology upgrades. But how do we keep our heating systems and cooling systems efficient; and how do we make old and existing heating systems and cooling systems last longer?

Preventative monitoring and servicing can play an important role in avoiding large bills for faults and replacement costs for heating and cooling systems. Below are just a few ways you can avoid those unwanted expensive bills:

  • Designed correctly and fit for purpose
  • Installed correctly
  • Cleaned & commissioned correctly
  • Maintained correctly

Failure to ensure any one of these 4 items will results in poor system performance, a reduce system lifetime and more expenses.

What happens if I do not treat my Closed System?


Systems that are not treated at least annually (commercial systems bi-annually) will begin to suffer from scale, corrosion, and gassing can occur as well as the potential for microbiological proliferation. System efficiency can see up to 30-40% reduction in system efficiency on sludgy and fouled systems.

Service process

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.

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 closed systems team


Customer Service Manager


Water Hygiene Engineers



Account Manager


Operations Director

Legionella Awareness Training FAQs

When and how often do I need a risk assessment to test for legionella bacteria?

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 bacteria.

This also applies if you are a private Landlord and have rental properties which are occupied. Landlords need to carry out legionella bacteria prevention measures and regularly assess the sources of risk to their water systems. Health and safety law requires that landlords ensure the control of substances hazardous, and meet all legal responsibilities and take a water risk assessment in order to ensure legionnaires disease preventions are met.

This includes taking suitable precautions to prevent, manage and control the risk of exposure to legionella bacteria. You can control the risk of legionella by undertaking the following: carrying out a risk assessment on all risk systems, 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 legionnaires disease record-keeping also known as monitoring.

Do I need testing, a legionella risk assessment or both?

​Legionella testing, water testing or sampling of risk systems is not to be confused with a legionella risk assessment. You are required by law to undertake a legionella risk assessment regularly under the Health and Safety Legislation 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, and ensure the successful control of legionella bacteria within a risk system.

Testing or sampling risk systems whilst not a legal requirement on their own plays an important role in determining how efficient a water system is managed. Your risk suitable and sufficient 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 of your risk systems, you will not know where and how many samples are required.

And without water testing/sampling you cannot determine how effective your harmful legionella bacteria control and management is. These two actions therefore should be undertaken together, not necessarily at the same time but in unison to effectively manage your risk from legionella bacteria. Another option for you to explore when it comes to controlling and managing legionella is to have a member of your staff undertake a legionella awareness training course.

Cold Water Systems 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 code 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 legionella risk assessments vary in prices depending on the number of cold 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 legionella risk assessments normally start from £250 to in excess of £750, however, our prices start from £99 depending on the size of the cold water systems 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 health and safety executive, 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. Our safety executive will assess the risk of legionella to your hot and cold water system. 

How Much is a Legionella Responsible Person Training Course?

Our legionella responsible person training course prices start at £35,00 plus VAT.

How long will legionella risk assessments 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 safety executive will assess the risk of legionella to your hot and cold water system.

Our engineers will work closely with you to ensure minimal disruption to your business is caused while they assess the risks to your hot and cold water tanks and system. Clear and easy access to rooms and buildings will play a part in the time spent on-site at your premises.

Are uRisk qualified?

Yes, all of our assessors are fully qualified health and safety professionals and accredited by City & Guilds legionella control association and can help assist you in meeting legionnaires disease compliance today for HSE (ACoP L8), and provide landlords with guidance for hot and cold water low-risk systems. 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 cold 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. Get in contact with us and book an appointment where we can carry out a legionella risk assessment. We will look at factors like your water temperature, redundant pipework, where your water is stored and test for bacteria in water systems.

Why choose uRisk?

25 Years Experience

Over 25 years of water hygiene and legionella control experience.

Customer Service Excellence

Friendly and simple advice by phone, email & online at your convenience.

City & Guilds Qualified

All staff are trained water hygiene consultants and engineers.

Nationwide Coverage

With engineers located all across the UK, we’re never too far away.

UKAS Accredited Testing

Our labs are UKAS approved providing you with quality assurance.

Full Compliance Services

Your one stop shop for legionella control, no need to go elsewhere.

A fabulous company, excellent customer service, they try to accommodate appoitments, and do there utmost in emergencies, been with them a few years now,  honestly cant fault them. Coming out of Covid 19, having our building urgently disanitised,  big thank-you to Luke and Lee for staying so late to get the job done!! Thank you Devon, for juggling the diary to fit us in so soon. A Team 🙂
Jo Maskell
Jo Maskell
18:02 15 Jun 20
Extremely happy with our legionella risk assessment carried out by uRisk, easy to understand and great customer service. Thanks again
Nickayla Robertson
Nickayla Robertson
21:22 15 Jan 19
Brilliant service! Thanks a lot for the hard graft
Leon Macauley
Leon Macauley
21:12 15 Jan 19
Brilliant Service, efficient, professional, punctual and friendly.
Alex Windsor
Alex Windsor
18:21 15 Jan 19
uRisk have been helping us with our Legionella Control for a number of years now. We've recently had a CQC audit and they were very impressed with our legionella compliance! Thank you for all your help.
Mike Port
Mike Port
20:41 07 Aug 18
Fantastic training courses and we've found the legionella risk assessment very easy to read and far more detailed than any we have previously had. 5 star service!
Gemma Pond
Gemma Pond
20:37 07 Aug 18
Incredibly detailed and professional team. Have been beyond helpful with with our CQC legionella compliance for our Safety. They’ve found solutions to fit around how we work and our budgets. We are always advised with reference to HSE which has been brilliant.
Amy Thorne
Amy Thorne
20:29 07 Aug 18
We're a small GP practice and started using uRisk for legionella risk assessments. We opted to use their remedial and monitoring services and they've been absolutely great. We cannot recommend them enough! Thank you so much!
Amanda Pates
Amanda Pates
18:30 07 Aug 18
Brilliant company, customer service was great! And engineers were fantastic. Thanks again uRisk! Will definitely be using them for all future work.
Nikesh Gohil
Nikesh Gohil
12:49 12 Mar 18

We want to help you comply!