..at 19:50
Lift top cover, run on drying cycle - no movement of drier air circulation motor.
Lift entire cast alloy cover complete with fan, heater, stats and trip etc. and find it choked up with fluff and jamming fan. Cover feels warm, so element must be running. Clean out, reassemble and test run again - now no heat.
Trace heater wiring and find 'non-reset-able over-temperature trip has tripped. Remove entire cover again plus element and reflector etc. to enable trip to be removed. Found there was no way to reset it, bugger!
Remembered some time ago hitting the same problem and a suggestion that there was a way to reset the throw-away item. Drills tiny hole between terminals at what looks like a centre mark and insert a small watch makers screwdriver and press gently - click.
Reassemble it all again and test run again. All working normally, refit top cover at 20:25 and push washer back into its spot.
35 minutes - SWMBO could have wasted that much time and more just tracking down an engineer to come out to it - and no warm self-satisfied glow inside.