Identifying method for lime-scale build-up in an electric heater in a hot-water heater/bath heater switches off a hot electric heater so as to measure and compare falling voltage during its cooling

摘要

A hot electric heater (1) is switched off and connected across a measuring bridge (3). As the electric heater cools down, falling voltage on it is measured and compared with a voltage curve that should be expected if the heater has not suffered lime-scale build-up. A signal for lime-scale build-up is derived from the results of the comparison. Independent claims are also included for the following: (a) A device for identifying lime-scale build-up in an electric heater in a hot-water heater/bath heater; (b) and for a hot-water heater/bath heater.