As it happened we had the element in stock. Electrue/Connect don’t even recognise the part number of the timer. The old Wash-Vac system did have a bigger coverage of Belling spares, but I suspect Belling has changed a bit in the last year or two.
The timer depends on diagnosis when we get there. Just being cautious prior to the visit. Customers prefer us not to take their money and then tell them we cannot source the part, so we usually test the water 1st when met with a different model number.