Today I once again came across an incorectly installed hot water cylinder, with no overflow pipe connected to the safety valve.

An incorrect installation of a hot water cylinder such as this can cause major damage and injury. As stated before in previous posts, when this safety valve begins to discharge water, the initial water that flows from it is boiling!

According to proper plumbing regulations, the safety valve has to have a 22mm metal overflow pipe discharging to the outside of the building at a safe place.  When the thermostat (this is the electrical appliance that regulates the temperature of the water inside the hot water cylinder) becomes faulty, then the element no longer stops heating the water inside the cylinder and this results in the water continuously heating up and eventually boiling continuously.

You can imagine the build up of pressure inside the cylinder due to the boiling water. And this is where the safety valve comes into play. In stead of the cylinder exploding the safety valve will release the boiling water resulting in an inflow of cold water inside the cylinder. Once the water has cooled down due to the new inflow of the new cold water then the safety valve could re-seal itself.

This may happen once or twice perhaps, but then the valve will discharge continually. In some instances the valve will discharge continuously from the first overflow. Possible symptoms to look out for indicating that the safety valve and/or thermostat have become faulty: 1. An increase in the consumption of electricity; 2. An increase in temperature of the hot water; 3. Discoloured hot water due to the boiling water churning up the sediment normally settled at the base of the tank (although this may also indicate that the hot water cylinder is rusting on the inside of the tank); 4. Sound of gushing water on the from the cylinder due to the safety valve discharging water; 5. Plastic gutter and/or down pipe melted due to discharged boiling water from overflow pipe from safety valve; 6. Scalded patch of grass outside due to boiling water discharged from safety valve; 7. Constant overflow of water to the outside of the building from the 22mm metal overflow pipe from the safety valve. What to do when the water is overflowing from the safety valve: 1. Turn off the main water supply to the house if you cannot get to the stop tap to the geyser. Switch off the electricity to the hot water cylinder. Open a hot tap on the bath to release the pressure to the cylinder and allow cold water into the hot water cylinder. Call DRIPS-AND-DRAINS or your local plumber to replace the thermostat and safety valve on your hot water cylinder.

MORE NEWS