Tank Clean and Sterilisations
Why conduct a tank clean and sterilisation?
Sediment is a naturally occuring mineral salt in the water, which can also pick up further debris from the rust inside the piepworks.
During the course of it's usage, a cold water storage tank will draw in sediment from the mains water it will begin to build. (like in the picture below)
The sediment can produce nutrients for any bacteria (which can cover a wide spectrum, but the most common is Legionella) already present, which can begin to multiply and affect the water and its associated systems.
To reduce the risk expose to these bacteria, a cold water tank clean and sterilisation is carried out. The sediment is removed and a sterilisaing agent is added to remove and remaining bacteria within the tank.
How often should a tank clean be carried out?
There is no set time period when a tank clean should be carried out, but it is recommended to conduct a tank clean and sterilisation annually.
Most times, a Legionella Risk Assessment surveyor will inform you that the cold water tank is considered to have a significant build-up of sediment and requires a clean.
In some cases, the tank is also rusted or has other defects which do not comply with regulations (such as the above example) in which case, the surveyor might suggest an immediate tank clean (which means it should be done within the next month). It might also result in remedial works to carried out during the tank clean and sterilisation, as the rust might produce pin hole leaks and other problems.