The last thing you need when you come back from holiday is to find your hot water cylinder has stopped working especially when you urgently just want to take a shower! Many people tend to turn their hot water cylinders off during this time. This in itself is not a problem unless your hot water cylinder is 10+ years old. Turning off the power to your hot water cylinder will of course allow the body of water inside the tank to COOL OFF, this is something your hot water cylinder is not used too as water is constantly maintained at 60 degrees. This “cooling off” will result in extreme contraction of the tank itself which initially does not cause the leak. Most Aucklander’s will coming back from holiday and the first thing they do is switch on the power to the hot water cylinder which will immediately power-up a 3KW element which in return will heat up the body of water back to 60 degrees in a relatively short mount of time. This will now cause the tank to expand very quickly. Depending on age this is when your hot water cylinder might spring a leak! Unfortunately we cannot give you advice whether to keep the power on or off during your absence but encourage you get your hot water cylinder serviced prior to going on holiday to ensure you don’t come back to any nasty surprises. In the image above the home owner was very fortunate that only the immersion heating element was damaged. Replacement of the element was under $200 and included a full check of the thermostat and hot water heating system.