Miele WDA 111 – over filling

Customer reported this machine is behaving oddly, taking a long time to complete cycle

I thought it was the heater or poor filling or draining but this is not the case. I selected the rinse/starch program and found that it was over filling. This would strongly point toward faulty pressure sensor but on the parts list, it appears that there are two types. One on the dispenser drawer in the form of flow rate sensor like you see in Bosch dishwashers and the second being the analog pressure switch. I am unable to access to exploded diagram and very reluctant to open up the machine as it is on a plinth a foot above the ground. For obvious reasons being heavy and a Lone Ranger that I only tackle it if it is absolutely necessary.

The model is WDA 111
Serial number is 64/147688967
M-Number is 10199340

Advice is always greatly appreciated
Thank you
Matt