BCBiodisc 18 Person Spares

BC Biodisc units have been through several design revisions over the years, so drive units, bearings and disc packs aren't always interchangeable between models. Check the data plate on your tank for the model reference and manufacture date, and compare it against the part specification listed for each spare. If you're unsure, send us the serial number and we can confirm fit before you order.

The gearbox and motor drive unit are the parts most likely to wear out, as they run continuously to rotate the biodisc media. Bearings and seals are also common failure points, particularly if the plant has been left running dry or without regular servicing. The rotating disc pack itself rarely needs replacing unless it's been physically damaged or badly fouled.

Simple items like bearings, seals and drive belts can often be replaced by a competent DIYer with mechanical experience, provided the unit is safely isolated first. However, gearbox and motor replacement usually involves working within a live sewage treatment plant, so many homeowners prefer to use a qualified service engineer. If your system is covered by a maintenance contract, check whether DIY repairs could affect that agreement.

Most manufacturers recommend an annual service visit to check bearing wear, motor condition and disc rotation speed, in line with the Environment Agency's general binding rules for package sewage treatment plants. Drive units typically last several years, but this varies with usage levels and how well the plant has been maintained. Regular servicing is the best way to catch a failing bearing or motor before it causes a full breakdown.

Common spares like bearings and seals are usually held in stock and can be despatched quickly, but gearboxes and complete drive units may need to be sourced to order, which can take longer. If your plant has stopped working, let us know it's urgent when ordering so we can advise on the fastest available option. In the meantime, avoid excessive water use to prevent the tank overfilling while it's offline.

Using a properly specified replacement part won't affect your legal discharge consent, as this relates to effluent quality rather than component brand. However, poorly matched parts — particularly the wrong gearbox ratio or an incorrect disc pack — can affect rotation speed and treatment performance. We supply spares matched to the original specification so the plant continues to perform as designed.