Cold Water Storage Tank Replacement London

Cold water storage tank replacement

Old galvanised and early plastic tanks corrode, distort and split, and many were installed before the current requirements for close-fitting lids, insect screens and insulation. We replace them with WRAS-approved tanks sized on real demand, install on proper bearers with support boards, fit a screened lid, warning pipe, servicing valve and insulation, then disinfect and re-test before handover. In lofts with restricted access we use two- or three-piece tanks so replacement does not mean removing a roof light.

• WRAS-approved tanks sized on actual demand
• Supported on boards and bearers correctly
• Screened lid, warning pipe and insulation fitted
• Sectional tanks where access is restricted

Loft water tank replacement

Loft tanks feeding a gravity system are still common in London houses and older flats. Signs a tank needs replacing include rust staining or debris in the water, a distorted or unsupported base, no lid or a lid that does not seal, a build-up of sediment that will not clean out, and repeated overflow from a failing float valve. We replace and reposition where the current spot makes servicing impossible, and take the opportunity to renew the ball valve, insulation and connections at the same time.

CWST cleaning, disinfection and chlorination

Cleaning is a planned operation, not a wipe-out. We isolate and drain the tank, remove sediment and biofilm, clean all internal surfaces, inspect the tank and its fittings, then chlorinate and disinfect to recognised practice, flush through and return the tank to service. Where required we take samples for bacteriological analysis and issue a certificate with photographs and readings for the log book. On occupied buildings we programme work overnight or at low-demand periods and arrange temporary supply where necessary.

• Drain, clean, inspect, chlorinate and flush
• Sediment and biofilm removed from all surfaces
• Sampling and certification for the log book
• Scheduled around occupancy with minimal downtime

Water quality and legionella control

A cold water tank is a favourite finding on any legionella risk assessment: uninsulated tanks warming above 20°C, missing lids and screens, stagnant water where storage is oversized, and debris in the base. We correct all of these — insulate and screen the tank, reduce stored volume where it is oversized for current demand, restore proper turnover, and clean on a scheduled cycle. Where a written scheme already exists we work to it and supply records that support it.

Ball valve replacement and overflowing tanks

Water running from a warning pipe outside, or a ceiling stain below a loft, is almost always a float-operated ball valve that has failed to shut off — a perished washer, a waterlogged float or a valve rated for the wrong pressure. We replace the valve with the correct type, set the water level below the warning pipe, and check the overflow and warning pipe are clear and correctly routed. Where the servicing valve has seized we renew that too so the next repair does not need the whole system drained.

• Ball valve and float replacement
• Water level reset below the warning pipe
• Overflow and warning pipe cleared and re-routed
• Seized servicing valves renewed

Repair, lining or replace

Not every failing tank needs replacing. A structurally sound sectional tank with surface corrosion or a failed internal finish is often better lined or coated, which avoids the cost and disruption of removing a large tank from a plant room. Where the tank is distorted, split or undersized for current demand, replacement is the right call. We survey and tell you which applies, and coordinate with our tank lining and coating service where refurbishment is the better option.