WATER TREATMENT, DRAINAGE & PIPED SERVICES


Heating health check; why testing should always come first


ADEY Commercial’s Mike Green, head of channel – commercial, discusses how a structured heating health check – built on proper water testing – can replace assumption with evidence and help you identify why things may have gone wrong, rather than just what isn’t working


H


eating system maintenance is often reactive. A pump fails, a radiator runs cold or a boiler starts acting up and under time and cost pressures, the response is to treat the


immediate problem. But before any tools are picked up, one simple question should come first: what condition is the system water in?


It’s a seemingly simple question but with real consequences. Corrosion, sludge and limescale don’t present you with loud warning signs when they start, rather they accumulate quietly, affecting heat transfer and system efficiency long before a fault becomes apparent. By this point, the damage has already been done, meaning repairs address the symptom rather than the cause.


The best way to understand the root cause is through structured water testing.


What water testing reveals about the health of your


tends to be sudden and disruptive, meaning unplanned downtime, emergency callouts, and repairs that cost considerably more than the equivalent scheduled intervention would have.


Creating a treatment plan


This is where water testing adds real value: it turns intervention from a general, best-practice checklist into a precise, evidence-based, proactive approach. A typical plan, based on test results, might include system cleaning or flushing, chemical rebalancing and inhibitor dosing, filter installation or optimising and a schedule of ongoing monitoring. The key difference to this approach is that the data comes first and the plan is then built around it, keeping engineers ahead of potential problems, rather than reacting to them. It ensures that work carried out addresses the actual root cause, not just the most visible symptom, and reduces the likelihood of a recurring issue a few months down the road.


heating system A well-rounded health check draws on more than just a visual inspection or spot check on single components. Proper testing and laboratory analysis of system water typically covers pH, inhibitor concentration, dissolved metals and suspended solids. Each of these points to a different stage or type of system degradation. It’s also important to distinguish magnetic from non-magnetic particulate. Magnetic content is a strong indicator of steel and iron corrosion (magnetite) while non-magnetic debris often points elsewhere, such as aluminium failure, scale, bio fouling or contamination introduced during installation or repairs. That distinction matters practically. Two systems can show similar symptoms – reduced output, uneven heat distribution – for entirely different underlying reasons. Without testing, it’s easy to treat the wrong one. This approach is backed by clear industry guidance. Two BSRIA guides set the industry benchmark here: BG29/2021 covers pre- commission cleaning, ensuring a system starts life free of mill scale, flux residue and installation debris, while BG50/2021 - Water Treatment for Closed Heating and Cooling Systems - sets out the ongoing expectations around water quality management, sampling and ongoing testing throughout a system’s operational life. Together, they’re widely regarded as the reference point for facilities managers, design engineers and maintenance teams choosing an appropriate water treatment strategy for closed-circuit systems. Testing to this standard isn’t an optional extra bolted onto maintenance - it’s the baseline against which good practice is measured, and increasingly the reference point clients and consultants expect engineers to work to.


Regulation is starting to catch up with this thinking, too. TS1, the new government-backed Heat Network Technical Standard, is set to introduce formal minimum requirements around water quality as part of the wider move toward regulated heat networks under the forthcoming Heat Network Technical Assurance Scheme (HNTAS). While TS1’s scope is currently limited to heat networks rather than closed heating systems generally, its direction of travel is telling: testing and water quality management are moving from best-practice recommendation toward a compliance expectation for a growing part of the sector.


Common issues uncovered by testing


In practice, testing water quality and system health regularly surfaces problems that wouldn’t otherwise be caught until they’d caused noticeable, measurable performance loss:


• Magnetite sludge accumulating in low- flow areas, restricting heat transfer at the heat terminal


• System water pH issues affecting aluminium components


• Active corrosion, often driven by oxygen ingress or inadequate inhibitor dosing


• Limescale on heat exchange surfaces, reducing boiler efficiency


• Circulation issues caused by blockages or underlying design weaknesses rather than component failure


• Depleted or incorrect chemical protection leaving the system exposed when it appears to be ‘treated’ • Bio activity driving corrosion


Individually, each of these can be minor. Left unaddressed, and often occurring in combination, they can compound and leave a system operating way below the expected performance based on age or maintenance history.


The cost of leaving water untested


The issues outlined above are not purely cosmetic. Left untested and untreated, they translate directly into reduced system performance. Reduced heat transfer efficiency shows up on energy bills, quietly inflating running costs without an obvious single cause. Accelerated component wear brings replacement forward, turning what should have been a planned, budgeted capital cost into an unplanned one. And where circulation faults or corrosion go undiagnosed, the eventual failure


Read the latest at: www.bsee.co.uk Benchmarking performance


Testing doesn’t just stop being useful once a treatment plan is implemented. The same data that informed the diagnosis also establishes a baseline to measure future performance against – allowing engineers to validate the success of any work and repairs, track system condition over time and demonstrate compliance and best practice. For organisations managing multiple sites or under scrutiny to evidence maintenance decisions, benchmarking is as valuable as the initial diagnosis itself. It converts water treatment from a one-off task into a measurable, ongoing performance strategy.


What a health check should include


For engineers looking to build testing into their standard practice, a genuinely useful health check typically covers:


• Representative sample collection - taken from an appropriate point in the system, following a consistent method so results are comparable over time


• The core parameters outlined above applied consistently - so results are comparable test to test, not a one-off snapshot


• A clear turnaround time - fast enough that results can inform a treatment decision without significant delay to the maintenance schedule


• A structured report, not just raw figures - one that flags which results sit outside acceptable ranges and what they typically indicate


• A follow-up testing point - built into the plan from the outset, so the effect of any treatment can be verified rather than assumed


Used consistently, this becomes less of a one-off diagnostic tool and more of a standing part of the maintenance regime.


A consultative “test first” approach


Ultimately, the case is simple: test first and let the evidence determine the action. Done consistently, this approach reduces risk, improves efficiency and helps ensure spend is dictated by what a system actually needs. It also reframes the relationship between engineer and system. It becomes less about fixing what’s broken and more about understanding what’s happening beneath the surface before deciding on the right course of action.


BUILDING SERVICES & ENVIRONMENTAL ENGINEER AUGUST 2026 25


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