A method of controlling a heater of a water heater, a water heater assembly, and a computer program

A method of controlling a heater of a water heater assembly that comprises a water tank and the heater, the method comprising the following steps:

• a) with a voltage meter, monitoring an input line voltage;
• b) with an energy level monitoring arrangement, monitoring an energy level of the water tank;
• c) with a control unit, determining whether the input line voltage is
• above an upper voltage limit;
• between a lower voltage limit and the upper voltage limit;
• or
• below the lower voltage limit;
• d) with the control unit, determining whether the energy level is
• above a maximum energy level;
• between a normal energy level and the maximum energy level;
• between a minimum energy level and the normal energy level;
• or
• below the minimum energy level;
• e) based on the monitoring and determinations in steps a) to d), run the heater if
• i) the measured line input voltage is above an upper voltage limit and the energy level is below a maximum energy level;
• ii) the measured line input voltage is between a lower voltage limit and the upper voltage limit, and the energy level is below a normal energy level;
• iii) the energy level is below a minimum energy level;
• and refrain from running the heater if
• iv) the energy level is above the maximum energy level;
• v) the measured input line voltage is between the lower voltage limit and the upper voltage limit, and the energy level is above the normal energy level;
• vi) the measured input line voltage is below the lower voltage limit and the energy level is above the minimum energy level.