How to Maintain a Compliant Cold Water Storage Tank
Maintaining a cold water storage tank is essential for meeting UK compliance standards, protecting public health, and ensuring long-term system reliability. Even a fully approved WRAS and BS EN 13280 tank will fail compliance if it is not inspected, cleaned, and serviced correctly.
This guide explains the step-by-step process to keep a tank compliant, including inspections, cleaning routines, and record-keeping. It is suitable for facilities managers, consultants, and installers who need to meet Water Supply (Water Fittings) Regulations 1999 and Health & Safety Executive (HSE) guidance.
Why Tank Maintenance Matters
- Health protection – prevents Legionella and other bacterial growth.
- Legal compliance – required under UK water regulations.
- Operational efficiency – reduces risk of leaks, contamination, and costly breakdowns.
- Evidence for regulators/insurers – logbooks and certificates demonstrate compliance.
Step-by-Step: How to Maintain a Compliant Tank
visual inspection
What to check:
- Cracks, leaks, corrosion, bulging panels.
- Insulation damage or gaps.
- Security of lids, vents, and overflow screens.
How often: Monthly or quarterly, depending on site risk profile.
Tip: Use a torch and thermometer to record water conditions.
Cleaning and Disinfection
What to do:
- Drain Tank Safely
- Remove sediment, scale, or debris
- Disinfect with an approved biocide or chlorine solution
- Flush and refill with potable water
Record Keeping
What to record:
- Inspection dates and findings.
- Cleaning and disinfection details
- Any repairs or remedial actions
Annual Service
What it includes
- Professional inspection of fittings, structure, and supports
- Verification of compliance with WRAS and BS EN 13280.
- A written compliance report for records and insurers.
Who should do it: A qualified contractor or the manufacturer’s approved service team.
Common Maintenance Issues and Fixes
- Issue: Build-up of sediment → Fix: Schedule more frequent cleaning.
- Issue: Unscreened overflow pipes → Fix: Install screened fittings to prevent contamination.
- Issue: Damaged insulation → Fix: Replace or repair insulation to maintain water below 20°C.
- Issue: Missing logbook entries → Fix: Keep records up to date and assign responsibility.
Tools and resources
- Maintenance Checklist PDF – download for on-site inspections.
- Tank Sizing Calculator – confirm system capacity remains suitable.
- Knowledge Hub Articles – additional guides on compliance and standards.
Common Maintenance Issues and Fixes
- Issue: Build-up of sediment → Fix: Schedule more frequent cleaning.
- Issue: Unscreened overflow pipes → Fix: Install screened fittings to prevent contamination.
- Issue: Damaged insulation → Fix: Replace or repair insulation to maintain water below 20°C.
- Issue: Missing logbook entries → Fix: Keep records up to date and assign responsibility.
At least once a year, with more frequent cleaning for high-risk buildings.
Visual inspections can be done in-house, but annual servicing should be carried out by trained professionals.
Even if work is carried out, regulators may treat the tank as non-compliant without documented evidence.
Read More...
- Water Tank Installation & Maintenance
- Cold Water Storage Tanks
- Case Studies
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A technical guide to cold water tank sizing methodology for multi-storey buildings — covering demand estimation, resilience calculations, water age, Legionella risk, and a worked sizing example.
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