Closed Water System Testing, Treatment & Monitoring
Closed water systems such as chilled water (CHW) and heating water systems (LPHW, MPHW, HPHW) require regular monitoring and treatment to prevent corrosion, scale, sludge and biofouling. At National Hygiene Services Ltd, our closed water system quality monitoring service delivers BSRIA-compliant testing, chemical treatment and UKAS-accredited analysis to maintain system efficiency, reliability and long-term asset protection.
Why Monitoring and Treatment is Essential
Without proper monitoring and control, closed water systems can suffer from:
- Corrosion of pipework and components
- Scale formation and heat transfer loss
- Sludge and sediment build-up
- Biofouling and microbiological activity
These issues reduce system performance, increase energy consumption, shorten equipment lifespan and result in higher maintenance and repair costs.

Our engineers are not only fully trained in carrying out works to meet guidelines set out in BSRIA documents BG 29/2021 and BG 50/2021, the British Standards documents BS 7593 and BS 8552, but also in ensuring the safety of everyone whilst testing is carried out. Any water samples taken are sent to a UKAS approved laboratory for testing. All instruments used in testing are calibrated to national standards and copies of certification are supplied with reports
Our closed water system quality monitoring service includes:
Why Choose Us for your Closed Water System Testing, Treatment & Monitoring?
Our collaborative and proactive approach drives efficiency, cost savings and offers our clients peace of mind. We are committed to continuous improvement, through innovation and investment in our personnel, methodologies and equipment.
We offer extremely competitive rates and daytime, evenings or weekends to offer minimal disturbance to our customers.
FAQ’s
How often should closed water systems be monitored and tested?
Most closed systems should be tested at least annually, with higher-risk or critical systems requiring more frequent monitoring.
What problems are caused by poor water quality?
Poor water quality can lead to corrosion, scale, sludge build-up, reduced heat transfer, increased energy use and premature equipment failure.
Are samples tested by a UKAS laboratory?
Yes. Water samples are analysed by UKAS-accredited laboratories, and full certification is provided with reports.












