Belt drifts to one side
Almost always a roller alignment issue. Check that every roller is square to the belt centreline. Also check tension symmetry — a difference in tension between the left and right edge will push the belt off.
Belt runs straight then drifts
Usually a temperature-induced elongation issue. If the belt drifts only after the oven reaches temperature, the two edges are expanding differently. Inspect the drive drum for parallelism and check for uneven heating across the belt width.
Belt runs straight but sags
Belt tension is too low, or belt weight is too high for the current support layout. Add support rollers or reduce belt length between supports.
When to call the manufacturer
If you have checked alignment, tension and drum parallelism and the belt still misbehaves, call the manufacturer. Send photographs and a short video. We can usually diagnose over a WhatsApp thread within an hour.
