A cold water storage tank is the bigger tank, near the small expansion tank, often located in the loft tucked out of site. This tank is filled directly from mains water. The gravity cold water storage tank is in charge of supplying your home's water needs to all of the taps in your house (bath taps, sink taps and showers) except for the cold water tap in the kitchen (as that is usually directly off the mains water). This tank also indirectly supplies the hot water taps, including the kitchen, with their hot water needs. This is achieved by feeding the cold water from the storage tank to the cylinder. The cylinder then heats up the water, which will then branch off to which tap is requesting a hot water source. As water drains out of the cylinder, with the request from the hot taps, the cold water storage tank will refill the cylinder with the amount of water it has lost to the taps. The cold water storage tank is able to fill up the cylinder from pressure as it is usually 3 or 4 metres above the cylinder.

How do I know if my cold water storage tank for mains water needs replacing?

The cold water storage tank is made of polyethylene plastic and might need to be replaced every ten years.

Signs that the cold water storage tank may need to be replaced include;

  • showing signs of age with cracks
  • cracks may have turned to splits and the tank is prone to leaking
  • age can make tank very brittle, 

How much will it cost to replace a cold water storage tank?

The biggest challenge when it comes to replacing a cold water storage tank, is getting the tank inside the loft through the loft hatch and removing the old tank via the loft hatch. As well as the accessibility for the plumber once inside the loft, whether it is safe to stand on loft floor boards and work around the tank with access to pipes.

If the access is relatively easy and the plumber will not have to cut up the old cold water tank to remove it through the hatch, this will result in the cost being lower with only a couple of hours labour time charged on top of the material charges. Cold water storage tanks that are designed size wise to pass through the hatch are referred to as ‘coffin loft tanks’.

Instead of a tank replacement, once the plumber has come through to diagnose the issue, the tank may just need a repair or a patch placed over a visible hole. This will drastically reduce the cost by only needing a 30 min to an hour repair work rather than changing all of the plumbing parts involved in a replacement of the cold water storage tank.

If you are doing a loft conversion and wanting the plumber to move the cold water storage tank to a new location, the plumber might insist on putting a new tank in the desired location. This would be if the existing tank is more than a few years old, as the plumber is reconfiguring pipework, and spending the same amount of labour setting the tank in its new location, they might as well set up a tank that has at least 10 years of life to avoid you having another costly expense in the coming years. Also when moving a brittle older tank, it could cause the tank to crack and leak and it may not be obvious immediately if the leak is subtle. Depending on the size of the tank, it may cost you a few hundred pounds for the tank with a lid, insulation jacket and some of the materials needed for the tank.

Cost to repair or replace a cold water storage tank

Per

Average cost

Replacing a dip tube in the cold water storage tank

Per hour 

£45

Fitting a new lid and insulation jacket in the cold water storage tank

Per hour 

£35

Replacing the cold water storage tank and removing the old tank

Per day

£260

Moving the cold water storage tank to a new location

Per day

£280

Repairing a hole in the plastic cold water storage  tank or lid

Per day

£40

Relining the cold water tank

Per hour

£180

Can my cold water storage tank be moved to a new location for a loft conversion?

Before you begin planning a loft conversion, if you have a gravity cold water storage tank and living in a maisonette home, you must determine whether the cold water feeds your house only or if it is shared with the house below you. Pre and post war homes, 1930’s - 1950’s, often have a shared system in the loft.

If it is shared, it is still possible to move the tank to a new location but you will need to make your neighbour aware as there will be two days of disrupted water services.

As the cold water storage tank relies on gravity, when moving it to a new location, the plumber will need to ensure it is at least 2 metres above showers and the cylinder of the boiler. This will enable better water pressure.

Older homes tend to have large galvanised steel or copper tanks, when moving the tank to a new position, the plumber will prefer to change this to plastic. The plastic tanks take up less space and the older tank will need to be cut with a welding machine to then be removed through the loft hatch.

Wherever the tank is installed be sure that it is covered with a lid and an insulation jacket plus if boxed in, make sure that there will be access to it for any future issues. 

Can a cold water storage tank be repaired?

Yes, depending on the extent of the damage to the tank. If you have noticed a very slight leak in the cold water storage tank, or that the lid has a hole, this can be ‘patched’ and repaired (in some cases even relined).

A small crack or pinhole that is above water level will be easier to repair as the plumber may just use a sealant to keep dust and insects from entering the tank. If the crack is below water level the plumber will have to first drain down the tank until the hole is exposed. They might use a plastic extrusion welder to inject molten polymer rod into the hole. When the rod has cooled, cut off the protruding bit and sand it down to smoothen the repair. There is always the risk that while repairing a crack or hole that the damage could be made worse, resulting in the need to replace the tank.

Instead of replacing a tank, relining the cold water tank might be an option. This can be a spray-applied Polyurea, (Water Regulations Advisory Scheme) WRAS approved solvent-free polyurethane coating, especially designed for relining drinking water tanks.Other repairs needed might involve just replacing a lid that has become warped or replacing old insulation that no longer does the job. If the water in the tank has become infected by bacteria (perhaps the lid was left off) then you will need a hygiene clean out of the tank, making sure that there is no sign of Legionella bacteria.


Estimates for common plumber jobs;

JobEstimate
Cost to fix a leak £240
Cost to unblock a clogged toilet £69
Cost to seal or re silicone a bath or shower £56
Cost to replace toilet float valve £41
Cost to replace a toilet £110
Cost to replace a bath £200
Cost to remove and refit a kitchen sink £110
Cost to replace kitchen mixer tap £151
Cost to install or remove a dishwasher £70
Cost to install a washing machine £70
Cost to replace heating expansion header tank £134
Cost to fit a new bathroom basin £162
Cost to fit an outside garden tap £68
Cost to fit a water softener £110
Cost to fit a macerator £80
Cost to replace a cold water storage tank £130
Cost to fit a boiling water tap £70

Rates for other trades

Replace cold water storage tank cost in the UK
Replace cold water storage tank cost in the UK (excluding VAT or callout charges)
Location in UKReplace cold water storage tank cost
Replace cold water storage tank near Aberdeen£268
Replace cold water storage tank near Amber Valley£229
Replace cold water storage tank near Angus£267
Replace cold water storage tank near Arun£260
Replace cold water storage tank near Ashfield£230
Replace cold water storage tank near Aylesbury Vale£279
Replace cold water storage tank near Barnsley£224
Replace cold water storage tank near Basildon£258
Replace cold water storage tank near Basingstoke & Deane£266
Replace cold water storage tank near Bassetlaw£225
Replace cold water storage tank near Bath & North East Somerset£255
Replace cold water storage tank near Bedford£271
Replace cold water storage tank near Belfast£208
Replace cold water storage tank near Birmingham£225
Replace cold water storage tank near Blackburn£232
Replace cold water storage tank near Blackpool£238
Replace cold water storage tank near Bolton£239
Replace cold water storage tank near Bournemouth£259
Replace cold water storage tank near Bracknell Forest£270
Replace cold water storage tank near Bradford£230
Replace cold water storage tank near Braintree£255
Replace cold water storage tank near Breckland£218
Replace cold water storage tank near Bridgend£219
Replace cold water storage tank near Brighton£258
Replace cold water storage tank near Bristol£252
Replace cold water storage tank near Broadland£235
Replace cold water storage tank near Broxtowe£231
Replace cold water storage tank near Bury£238
Replace cold water storage tank near Caerphilly£220
Replace cold water storage tank near Calderdale£225
Replace cold water storage tank near Cambridge£268
Replace cold water storage tank near Canterbury£241
Replace cold water storage tank near Cardiff£228
Replace cold water storage tank near Carmarthenshire£193
Replace cold water storage tank near Charnwood£223
Replace cold water storage tank near Chelmsford£255
Replace cold water storage tank near Cheltenham£292
Replace cold water storage tank near Cherwell£266
Replace cold water storage tank near Chester£218
Replace cold water storage tank near Colchester£251
Replace cold water storage tank near Conway£200
Replace cold water storage tank near Coventry£229
Replace cold water storage tank near Crewe & Nantwich£228
Replace cold water storage tank near Dacorum£272
Replace cold water storage tank near Derby£225
Replace cold water storage tank near Doncaster£226
Replace cold water storage tank near Dover£242
Replace cold water storage tank near Dudley£226
Replace cold water storage tank near Dumfries & Galloway£243
Replace cold water storage tank near Dundee£270
Replace cold water storage tank near East Ayrshire£183
Replace cold water storage tank near East Devon£245
Replace cold water storage tank near East Dunbartonshire£260
Replace cold water storage tank near East Hampshire£257
Replace cold water storage tank near East Hertfordshire£275
Replace cold water storage tank near East Lindsey£262
Replace cold water storage tank near East Riding£207
Replace cold water storage tank near Eastleigh£261
Replace cold water storage tank near Edinburgh£253
Replace cold water storage tank near Elmbridge£283
Replace cold water storage tank near Epping Forest£286
Replace cold water storage tank near Erewash£231
Replace cold water storage tank near Exeter£260
Replace cold water storage tank near Falkirk£258
Replace cold water storage tank near Fife£259
Replace cold water storage tank near Flintshire£229
Replace cold water storage tank near Gateshead£242
Replace cold water storage tank near Gedling£231
Replace cold water storage tank near Glasgow£256
Replace cold water storage tank near Gloucester£309
Replace cold water storage tank near Guildford£286
Replace cold water storage tank near Gwynedd£232
Replace cold water storage tank near Halton£229
Replace cold water storage tank near Harrogate£219
Replace cold water storage tank near Havant & Waterloo£251
Replace cold water storage tank near Highland£320
Replace cold water storage tank near Horsham£266
Replace cold water storage tank near Huntingdonshire£264
Replace cold water storage tank near Ipswich£294
Replace cold water storage tank near Isle of Wight£243
Replace cold water storage tank near Kings Lynn & West Norfolk£233
Replace cold water storage tank near Kingston-upon-Hull£207
Replace cold water storage tank near Kirklees£226
Replace cold water storage tank near Knowsley£224
Replace cold water storage tank near Lancaster£255
Replace cold water storage tank near Leeds£225
Replace cold water storage tank near Leicester£225
Replace cold water storage tank near Lisburn£210
Replace cold water storage tank near Liverpool£225
Replace cold water storage tank near London£282
Replace cold water storage tank near Luton£283
Replace cold water storage tank near Macclesfield£232
Replace cold water storage tank near Maidstone£247
Replace cold water storage tank near Manchester£231
Replace cold water storage tank near Mid Bedfordshire£274
Replace cold water storage tank near Mid Sussex£263
Replace cold water storage tank near Middlesbrough£258
Replace cold water storage tank near Milton Keynes£270
Replace cold water storage tank near Neath Port Talbot£227
Replace cold water storage tank near New Forest£258
Replace cold water storage tank near Newbury£272
Replace cold water storage tank near Newcastle-under-Lyme£219
Replace cold water storage tank near Newcastle-upon-Tyne£243
Replace cold water storage tank near Newport£226
Replace cold water storage tank near North Ayrshire£230
Replace cold water storage tank near North East Lincolnshire£279
Replace cold water storage tank near North Hertfordshire£275
Replace cold water storage tank near North Lanarkshire£257
Replace cold water storage tank near North Lincolnshire£214
Replace cold water storage tank near North Somerset£247
Replace cold water storage tank near North Tyneside£241
Replace cold water storage tank near North Wiltshire£297
Replace cold water storage tank near Northampton£266
Replace cold water storage tank near Norwich£238
Replace cold water storage tank near Nottingham£227
Replace cold water storage tank near Nuneaton & Bedworth£228
Replace cold water storage tank near Oldham£235
Replace cold water storage tank near Oxford£283
Replace cold water storage tank near Pembrokeshire£204
Replace cold water storage tank near Perth & Kinross£278
Replace cold water storage tank near Peterborough£261
Replace cold water storage tank near Plymouth£234
Replace cold water storage tank near Poole£258
Replace cold water storage tank near Portsmouth£246
Replace cold water storage tank near Powys£288
Replace cold water storage tank near Preston£244
Replace cold water storage tank near Reading£271
Replace cold water storage tank near Redcar & Cleveland£260
Replace cold water storage tank near Reigate & Banstead£281
Replace cold water storage tank near Renfrewshire£260
Replace cold water storage tank near Rhondda, Cynon, Taff£208
Replace cold water storage tank near Rochdale£236
Replace cold water storage tank near Rochester-upon-Medway£280
Replace cold water storage tank near Rotherham£225
Replace cold water storage tank near Salford£231
Replace cold water storage tank near Salisbury£269
Replace cold water storage tank near Sandwell£224
Replace cold water storage tank near Scarborough£228
Replace cold water storage tank near Scottish Borders£370
Replace cold water storage tank near Sefton£225
Replace cold water storage tank near Sevenoaks£260
Replace cold water storage tank near Sheffield£229
Replace cold water storage tank near Slough£278
Replace cold water storage tank near Solihull£227
Replace cold water storage tank near South Ayrshire£218
Replace cold water storage tank near South Bedfordshire£271
Replace cold water storage tank near South Cambridgeshire£262
Replace cold water storage tank near South Gloucestershire£255
Replace cold water storage tank near South Kesteven£263
Replace cold water storage tank near South Lanarkshire£262
Replace cold water storage tank near South Oxfordshire£269
Replace cold water storage tank near South Somerset£252
Replace cold water storage tank near South Tyneside£242
Replace cold water storage tank near Southampton£258
Replace cold water storage tank near Southend-on-Sea£249
Replace cold water storage tank near St Albans£282
Replace cold water storage tank near St Helens£225
Replace cold water storage tank near Stafford£225
Replace cold water storage tank near Stockport£236
Replace cold water storage tank near Stockton-on-Tees£258
Replace cold water storage tank near Stoke-on-Trent£220
Replace cold water storage tank near Stratford-on-Avon£254
Replace cold water storage tank near Stroud£277
Replace cold water storage tank near Suffolk Coastal£306
Replace cold water storage tank near Sunderland£243
Replace cold water storage tank near Swale£247
Replace cold water storage tank near Swansea£225
Replace cold water storage tank near Tameside£231
Replace cold water storage tank near Teignbridge£255
Replace cold water storage tank near Tendring£284
Replace cold water storage tank near Test Valley£260
Replace cold water storage tank near Thamesdown£301
Replace cold water storage tank near Thanet£242
Replace cold water storage tank near The Wrekin£231
Replace cold water storage tank near Thurrock£258
Replace cold water storage tank near Torbay£259
Replace cold water storage tank near Trafford£234
Replace cold water storage tank near Vale of Glamorgan£223
Replace cold water storage tank near Vale of White Horse£284
Replace cold water storage tank near Vale Royal£234
Replace cold water storage tank near Wakefield£229
Replace cold water storage tank near Walsall£222
Replace cold water storage tank near Warrington£234
Replace cold water storage tank near Warwick£239
Replace cold water storage tank near Waveney£251
Replace cold water storage tank near Waverley£273
Replace cold water storage tank near Wealden£254
Replace cold water storage tank near West Lancashire£228
Replace cold water storage tank near West Lothian£273
Replace cold water storage tank near West Wiltshire£297
Replace cold water storage tank near Wigan£227
Replace cold water storage tank near Windsor & Maidenhead£274
Replace cold water storage tank near Wirral£226
Replace cold water storage tank near Wokingham£272
Replace cold water storage tank near Wolverhampton£223
Replace cold water storage tank near Wrexham Maelor£239
Replace cold water storage tank near Wychavon£272
Replace cold water storage tank near Wycombe£281
Replace cold water storage tank near York£228