Case study: Closed System Online Clean for a local school & sixth form

Project outline:

We were contacted by the client, a school and sixth form, who needed help with their heating system. The system was showing signs of high levels of corrosion from their sidestream filtration filters. The filters were having to be changed on a regular basis at a great cost to the client and were showing no signs of improvement.

The client wanted a solution to the problem that would prevent further corrosion within their heating system, which eventually would have needed to be replaced at a huge cost.

We decided that an online clean of the system was the best solution.

We’d thoroughly recommend working with Aquatrust. The team were both knowledgeable and professional, which meant the job went extremely smoothly. With their wealth of expertise, Aquatrust helped us to identify the problem and came up with a solution that means we no longer have to worry about corrosion in our heating system. We now have the confidence that our heating system is running as well it should be.

Marshall Sharp
Senior Campus Manager, Dixons Academies Trust

Project Description

We carried out a thorough, initial analysis on the levels of corrosion and ultimately recommended that an online clean of the system – a Closed System – was undertaken.

We used a solid chemical cleaning technology. We used a non-intrusive rig to pump the chemical around the system, which worked to filter the corrosion out of the heating system.

We worked in partnership with Dosafil and Solidtek to install the online cleaning rig and sample the results on a weekly basis, over a period of 8 weeks. Filter bags also needed to be changed by on-site staff on a regular basis, so we called down every week to monitor this and check the stock levels of the filter bags.


Our main challenge was ensuring that the whole system was cleaned. We had to take samples from different parts of the system, which wasn’t straightforward as there were no radiators on site that we could take the samples from. Instead, we had to take samples from different points within the plant room.

We needed to limit disruption in the day-to-day running of the school. The great thing about an online clean is that it causes little or no disruption to the school’s daily operations. It could also be installed in isolation in the main plant room, meaning it was kept away from the busy student area.


We successfully performed the necessary cleaning process for the school, helping to prevent any further corrosion to the heating system.

This project was unique as the solid chemical technology that we used from Solidtek was cutting edge and not something yet used widely within the industry. Performing an online clean meant we could operate while the school was open with no disruption, as well as no, or very minimal, water wasted – something else that contributed to the success of the clean.