There could be a multitude of reasons why your hot water system isn’t working:

  1. First off, establish the type of hot water system you have: Gas, electric, heat pump or solar hot water systems.
  2. Second, once you have established the type of unit you have you need to identify where the problem is. Is the hot water unit itself hot but the water in your taps not? The answer to this question will lead you to whether the supply to the tank is faulty (Gas, electrical, solar) or whether the problem lies downstream of your tank (tempering valve or pipework).