On this model it is more likely to be the micro switch (8) that is overheating ot the brushes need replaced.
http://www.showerdoc.com/shower-spares/supajet/SUPJ-1580800-SupaJet-Micro-switch-1580800
http://www.showerdoc.com/shower-spares/supajet/HYDR-01102-Sintech-Motor-Carbon-Brushes-(pair)---In-Brass-Casing-01102