What is the reason electric heating device is not working?How to deal with it?

There are three reasons.Firstly,the control system is failing;secondly,the solar water tank’s temperature is over 70 degrees;thirdly,the electric heating pipe was broken.And there are three methods to deal.Firstly,,repair or replace the controller;secondly,electric heating pre-set self-protection;thirdly,replace the electric heating pipe.