Graf sewage treatment plants — including the highly regarded Graf Klaro and Graf One2Clean ranges — are designed to deliver excellent wastewater treatment with low energy use and reliable performance. However, even the best systems require routine professional servicing to remain safe, compliant, and efficient.
Over time, treatment plants naturally accumulate sludge and can suffer from wear to air blowers, diffusers, valves, and control systems. If these issues are ignored, performance drops and you may start to experience odours, alarms, poor effluent quality, blockages, or total system failure. In addition to the inconvenience, poor treatment can lead to non-compliant discharge and potential enforcement action under the 2020 General Binding Rules.
Clearmasters provide full servicing for all Graf models, following manufacturer guidelines and Environment Agency standards. Our engineers check every critical component, confirm proper biological treatment is taking place, and provide a clear service record for your compliance files.
With over 30 years of wastewater experience across the South East, Clearmasters are trusted Graf servicing specialists for domestic and commercial sites.
Your Graf Klaro or One2Clean system should be serviced regularly, and there are also warning signs that servicing is required sooner than planned.
If you notice any of these issues, Clearmasters can attend quickly, diagnose the cause, and restore full system performance.
While professional servicing is essential, there are simple steps homeowners and site managers can take to help keep a Graf Klaro or Graf One2Clean system running smoothly between visits. These small checks help maintain biological balance, reduce stress on mechanical parts, and prevent avoidable faults.
If you notice persistent odours, high water levels, blower alarms, or cloudy effluent, it’s important to get the system checked quickly. Early intervention prevents major breakdowns and keeps your plant compliant.
Clearmasters offer fast response times and expert support across the South East, ensuring your Graf system remains reliable, safe, and fully compliant all year round.
Graf manufacture two of the UK’s most trusted sewage treatment systems, each with slightly different servicing requirements. Knowing your model helps ensure the correct maintenance approach.
Whatever model you have, Clearmasters follow Graf guidance and Environment Agency standards to keep your system working exactly as designed.
Every service follows Graf’s manufacturer checklist and UK compliance requirements:
We assess blower output, aeration balance, and biological treatment performance to confirm the plant is working efficiently.
Inspection of air pumps, filters, valves, pipework, diffusers and seals, replacing worn parts where needed.
We measure sludge depth to confirm whether desludging is required to maintain correct biological treatment.
Visual and operational checks confirm the final discharge meets expected clarity and standards.
We test alarms, timers, and electrical safety to ensure reliable operation and early fault detection.
You receive a full service report with findings, recommendations, and compliance documentation.
Our engineers will talk you through the results in plain English and advise on any maintenance or repairs needed.

Trusted wastewater specialists across the South East
Clearmasters have been servicing sewage treatment plants for over 30 years, including the full Graf Klaro and One2Clean range. We understand how Graf systems are designed to perform and how to keep them operating at peak efficiency.
Our engineers carry specialist testing equipment and manufacturer-approved parts, allowing us to resolve issues quickly and prevent repeat faults. We provide clear service records that support property sales, insurance claims, and Environment Agency compliance.
From single domestic systems to larger commercial installations, you’ll receive honest advice, competitive pricing, and a friendly professional service every time.
Most Graf systems require one professional service every 12 months to remain compliant and efficient. For commercial premises or properties with higher daily flow, Graf plants may need more frequent servicing to keep the biological process stable.
If you’re unsure what schedule is right for your Graf system, Clearmasters can assess your installation and set up a tailored maintenance plan.
Graf recommends annual servicing for domestic properties. Commercial or high-load systems may require servicing every 6 months.
Yes. One2Clean models have fewer mechanical parts, but still require annual aeration checks, sludge measurement, and compliance testing.
This usually indicates worn diaphragms, blocked air lines, failing diffusers, or excessive sludge. A service identifies and fixes the cause.
Odours typically indicate poor aeration, biological imbalance, or sludge overload. Servicing restores correct treatment conditions.
Yes. We service all generations of Graf Klaro and One2Clean systems, including older or discontinued models.
Yes. We provide 24/7 emergency response for alarms, blower failures, high levels, or system shutdowns.