how do i fix back ring on induction hob Rangemaster?

https://www.justanswer.co.uk/appliance/90eek-dose-anyone-know-e4-means-rangemaster-induction.html

z vlkn
December 2019

This will probably be a fault with the main circuit board or module. That code indicates that the induction coil is not communicating with control pcb - expensive parts to replace I'm sorry to say. If you are able to, get a multimeter out and test the resistance on the suspect coil and compare to the figure on one of the working ones, this will help you rule out if it simply a failed coil (ring)
Without specialist test equipment, it MAY be possible to swap a few parts around temporarily and try to run it breifly and carefully to see if it helps identify the faulty part. Only do this if it is practical and safe to do so.
Ultimately, if you are unable to safely do this, you'll need a rangemaster engineer out and be prepared to say goodbye to several hundred quid :-(

Rupert
December 2019