CK kindly advised me that the energy regulator might be faulty and he was correct: I replaced it with an ER110B1 and all was OK. Two weeks later with all 4 knobs OFF the four neons lit up to indicate that the plates were on. Simultaneously, the neons came on to say that one or more plates was hot. None were on, none were hot. Only turning the unit off at the wall switch will put these lights out

John Canning, July 2010