Closed Water System: The Ultimate Maintenance Plan

Closed System Remedial Work

A Maintenance Plan that Will Extend the Life of your Closed System

Closed systems save money and energy when they are properly maintained, but without timely maintenance, closed systems can suffer from blockages or erosion of susceptible components that decrease their efficiency and can have high repair costs for system owners. If left untreated or if incorrectly treated components can eventually break down completely and require replacement.  

A maintenance plan can help prolong the life of your closed systems by addressing problems before they lead to failure.  


The article was written by Kris Rowland, our Head of Technical, Training and Compliance. Kris has more than 20 years of experience in the industry and is responsible for monitoring our clients’ compliance.

Sign up to our newsletter

Keep up to date with the world of water treatment


What this article is going to discuss:

  • What is a closed system?
  • Common issues within a closed system
  • What can I do to keep my closed-system in good shape?
  • Our closed system maintenance plan services

What is a Closed System?

Closed water systems use water as either a coolant or for heating. Closed water systems are designed to be filled ‘once’ with water and then circulated for long periods of time without any significant ‘make-up’ with replacement water. Unfortunately, due to a lack of proactive maintenance these systems can be continually topped up with raw water which can cause or exacerbate common issues found in man made water systems. 

Common problems within a Closed System

  • Scale formation  
  • Corrosion 
  • Fouling 
  • Microbiological fouling 

Closed System Misconceptions

Caring for closed systems can be a challenging task, however Kris Rowland, our Head of Training, Technical and Compliance has demystified some of the common misconceptions…


What can I do to keep my Closed System in good shape?

Water Treatment for Closed Heating and Cooling Systems (BG 50/2021) (

Pre-Commission Cleaning of Pipework Systems Amended 6th edition (BG29/2021) (

Firstly, when a closed system is built, it must be commissioned correctly. A treatment regime should be put in place at the start of the system’s lifecycle. This treatment regime should be relevant to each individual system and include a pre-commission clean to ensure so that contaminants left behind by manufacturing are removed. Following installation, a planned maintenance plan for your closed system should include: 

  • Regular monitoring (by a combination of physical checks as well as sampling at the correct frequency from suitable locations)
  • Should monitoring indicate that the system is deteriorating then there are a number of remedial actions that can be taken.

Sampling Plan

You should begin by putting a sampling plan in place, because you don’t know the condition of your system if you don’t test it. You should sample at regular intervals and take samples from the same places. This will give you a clear picture of your system and trends in metal content as an indicator of corrosion, indicators of fowling and scale formation, and changes in other water quality parameters.

Why are Closed System maintenance plans important?

A maintenance plan is an essential part of the life of any water system, and it is important that you have one in place.

A maintenance plan ensures that all parts of your water systems are regularly inspected and maintained in order to avoid any damage, degradation or risk to the system.

A maintenance plan also allows for regular inspections, which can identify potential problems before they become too big to deal with easily. By identifying problems early on, there’s a greater chance that they can be fixed without causing too much disruption to your day-to-day operations.

In addition to identifying problems early on, having a maintenance plan also means that you’ll know what needs doing when it comes to repairs or replacements. This means that you’ll get more value out of your money as well as making sure that everything works properly at all times.

Get in touch to arrange a Closed System maintenance plan

Maintaining a closed water system as proficiently as possible comes with a great deal of time, effort, and money. But, performing these processes regularly and at the right time will result in a system that is more reliable and efficient, while also playing an important role in conserving energy. With our innovative software solution, all remedial work and checks will be recorded on our Zetasafe system. This means that you can conserve energy, improve efficiency, and limit paper waste by adopting our software solution. Contact us today to talk about how we can help improve your maintenance plan.