Electric water heater element and thermostat problems.
Does your main swith or consumer unit circuit breaker trip when you turn on the water heater?
The heating element in your water tank (most often on the roof) has likely corroded from the hard water and will need replacing.
A general plumber is not licenced to carry out the electrical testing and reconnecting of electrical circuits, so your first call should be to a licensed Cyprus electrical contractor.
Call 95509007 for our friendly and profesional 24 hour electrical service.