Closed Systems

Closed systems are typically low pressure hot water (LPHW or LTHW) and chilled or condenser water systems

The water quality problems associated with closed systems are Scale, Corrosion and Microbiological fouling. Phase Technology has specialist knowledge in these areas and can design a complete treatment regime’s so that closed systems can operate trouble free.

Treatment and Analysis

The treatment of closed heating and cooling systems is often a combination of chemical and physical means. Phase Technology has a range of chemical products suitable for different system components. Our chemical inhibitors, combined if necessary with filtration provide excellent protection to closed systems.


  • We can undertake on site analysis for instant results or more in depth System Audits provided by our laboratory.

Accreditations and affiliations

Legionella Control Association

Phase is a member of the LCA. The LCA was established to ensure users receive a high level of audiatable services that are in full compliance with the guidance set out in L8

Safe Contractor

Phase Technology is accredited by SafeContractor providing our clients peace of mind that the work is undertaken competently and safely

ISO Environmental

Phase Technology holds ISO 14001:2015

ISO Quality

Phase Technology has been ISO accredited since 1996 and currently holds ISO 9001:20015

Human Focus

Phase Technology is accredited at Organisation Level by Human Focus for General Health & Safety Arrangements. This certification scheme has been independently accredited by RoSPA

Cyber Essentials

Phase Technology is Cyber Essentials certified.

Remedial Works

Whether through inappropriate treatment or incorrect pre-commission cleaning Phase Technology can provide a solution to the problem

Chemical Cleaning and Flushing
The type of cleaning depends on the severity of the problem and other constraints such as an occupied building or the need to keep a system operational. Often chemical cleaning agents and flushing is used in conjunction with temporary filtration to achieve the bet results.

Pseudomonads Removal
Analysis and eradication of pseudomonads in closed systems is an area where Phase Technology has proven success using our biocide range.

We are able to offer a range of cyclone and media filters to control and remove suspended solids from closed systems.

Scale can cause significant problems for equipment such as condensers, plate heat exchangers and calorifiers. Phase Technology can provide a descaling service to restore plant to a safe condition and maximise operational efficiency.