High electricity charges only in one of the units

[Eldar M.]

Fellow BP's

I am in need of some assistance in trying to fix an electrical issue in a multi unit rental property.

There is one unit of a 7 units property where the tenant is complaining of an extremely high electricity bill. The property is an electric and no gas building. The tenants are 2 adults but use reasonable amounts of electricity. The average DWP bill has been close to $400 during the summer and even higher in the $700s during the winter due to portable heating devices. The units has electric heating that runs through the ceiling with heated cords(this is what has been explained to me but I'm not too sure) however the heater is broken and is not working. We had been told that in order to repair this, the ceiling will have to be ripped out. Can this be part of the issue?

This is extreme high for the little they claim to use. Can any one help with any possible issues and or lead me to an affordable/ knowledgable electrician because the ones we've called cannot seem to locate the issue? We don't want to scare the tenant away by being forced to move. If this is not resolved now, this will continue to be an issue for all future tenants in this particular unit.