Hi Daliti
well put it another way I would consider switching the neutral or common as poor practice, which will eventually see the culprit come un-stuck or some poor sod comming after him. Me I don't switch commons/neutrals, the same as I don't purge air from fridge systems, others can do as they see fit
You could also be having a partial suply voltage from the coil of the eliwell controllers, dependant on what internal protection they have to prevent this.
Safer wire in a relay or contactor to drop the suply voltage to the solinoides (tru a n/c contact)
Kind Regards. Andy