How often?
HSG274 recommends inspecting cold water tanks at least annually. Cleaning and disinfection is needed when the inspection shows debris, sediment, scale, corrosion or contamination, rather than on a fixed timetable.
Warning signs
- Visible sediment or slime on the tank floor or walls
- Loose or missing lids, or screens missing from vents and overflows
- Insects, birds or vermin
- Water temperature above 20°C in the tank
- Poor turnover because the tank is oversized for current use
The process
A professional clean involves isolating and draining the tank, removing debris, cleaning the surfaces, disinfecting with chlorine at a controlled concentration and contact time, flushing, refilling and certifying. Our tank cleaning service includes photographs before and after.
Upgrades worth considering
Many older tanks do not meet the Water Supply (Water Fittings) Regulations 1999. Upgrades include close-fitting lids, insect screens on vents and overflows, and insulation to keep the water cool.
Frequently asked questions
Can I clean my own water tank?
It is possible but not recommended. Chlorine handling, confined spaces and correct disinfection need training and the right equipment.
Disclaimer: This guide is general information about UK requirements and is not legal advice. Always check the current legislation and guidance for your premises.