BABiodisc 6 Person Spares

BA Biodisc units have gone through several design revisions over the years, so it's worth checking the model plate or serial number on the tank lid before ordering. Motor, bearing and rotor assemblies in particular can differ between older and newer 6-person models. If you're unsure, send us the serial number or a photo of the dataplate and we'll confirm the correct part.

The motor and gearbox drive unit, the rotor bearings and the rotating biozone discs are the most common failure or wear points, typically due to continuous running and the damp environment inside the tank. Diffuser membranes and seals also degrade over time and are a sensible item to keep as a spare. Replacing these promptly prevents knock-on strain on the motor and helps avoid a full treatment failure.

Simple items such as diffusers, seals and covers can usually be fitted by a competent homeowner with basic tools. However, motor, bearing and rotor assembly replacements involve working inside a live sewage treatment tank and often require isolation and re-priming of the system, so we'd recommend a qualified drainage or wastewater engineer for these jobs. Getting it wrong can affect treatment performance and may void any remaining warranty on the plant.

Motors and bearings typically last several years under normal domestic use, but this varies with usage levels, electricity supply consistency and how well the unit has been maintained. Most manufacturers recommend an annual service, at which point a competent engineer will check wear on rotor discs, bearings and seals and flag anything nearing the end of its life. Keeping a spare motor or bearing kit on hand is sensible for anyone off-mains who can't afford downtime.

If the rotor stops, the biological treatment process halts and untreated or partially treated effluent can start discharging, which is both a performance and compliance issue. This is usually caused by a failed motor, seized bearings or a broken drive belt/chain, all of which are common spares for this range. Don't leave it running in this state for long — arrange a repair or replacement part as soon as possible to avoid a backlog in the tank.

We hold a range of the more commonly requested Biodisc spares, including motors, bearings and diffusers, ready to despatch. Larger or less common assemblies may need to be ordered in specially, so lead times can vary — if your plant is completely out of action, let us know and we'll advise the fastest option available. It's always worth checking stock and delivery estimates before you commit to a service date.