FAQ - Hot Water

  • What is the recommended temperature for a hot water cylinder?
  • What is a safe temperature for hot water coming from your tap?
  • Problems with hot water systems?
  • No hot water?
  • How does your hot water cylinder work?


What is the recommended temperature for a hot water cylinder? 

  • It is generally recommended that you keep the temperature at 65°C, and definately not lower than 60°C .

What is a safe temperature for hot water coming from your tap?

  • A safe temperature for hot water coming from your tap is 55°C. At this temperature a serious burn to a child's skin will take 10 seconds. Even safer is 50°C. This allows about a minute before a serious burn occurs. The recommended temperature of hot water coming from the tap in rest homes and child care facilities/schools is 45°C.


 No Hot Water?

This often happens at the most inconvenient times, however these helpful checks may save you the cost of a plumber or electrician call out charge.

  • Power Supply - your power provider may have a problem with the power supply to your hot water cylinder. As the power provider controls the electricity to your hot water heater, you may want to contact your power provider and request a tariff control check as it may be a fault which they are responsible for.
  • Hot Water Heater - there may be a fault with the heating element, thermostat or tempering valve.
  • Extra Load - if there is an extra demand on your hot water heater, i.e. guests staying, this may explain your lack of hot water. Alternatively, the hot water heater may not be of sufficient size to meet the needs of the household. There are some options with this problem worth discussing with your local plumber, Redsea Plumbing

How does your HWC work?

A water heater consists of the following parts:

  • A heavy inner steel tank that holds the hot water
  • Insulation surrounding the tank
  • A dip tube to let cold water into the tank
  • A pipe to let hot water out of the tank
  • A thermostat to control the temperature of the water inside the tank
  • Heating elements to heat the water
  • A drain valve that allows you to drain the tank to replace the elements or move the tank
  • A pressure relief valve
  • A sacrificial anode rod to help keep the steel tank from corroding



A water heater uses nothing more than the "heat rises" principle to separate hot water from cold water in the tank. As cold water comes in, it remains at the bottom of the tank because it is denser than hot water. If you use the hot water faster than the heating elements can heat the incoming cold water, and if you consume all of the hot water that the tank holds, you run out of hot water in the middle of your shower.