By Emily Rivers
Last updated 7th September 2022

A vented hot water cylinder is also known as a gravity-fed hot water cylinder. This is because the vented cylinder works on a gravity system by having the water supplied from the cold water tank, also known as a header tank, which is often stored in the loft or on a higher floor, as the system relies on gravity to build pressure.

The name 'vented hot water cylinder' is because the 'open vent' is a pipe which acts as a safety mechanism releasing built-up pressure. The vent pipe runs from the cylinder back up to the feed and expansion tank, releasing the built-up water pressure in the tank to stop the system from overheating. Vented cylinders often are made of copper or stainless steel and a cheaper system to install than an unvented system.

When should I choose a vented cylinder?

If it is time for a heating engineer to replace your vented hot water cylinder, the easiest installation is usually going with a similar set-up to what is already installed needing replacing. This will be because the pipework is in place, ready for the cylinder to just be swapped out for a newer version.

Older UK properties tend to have vented cylinders. This means the pipework plumbed in throughout the home, was designed for a low-pressure system. Replacing the hot water cylinder with a different set-up may require pipework to be replaced to handle the higher pressure of a pressurised system. This of course would add to the installation costs.

Choosing a vented cylinder will need a home that has a loft space for the header tank or an upstairs storage space as the cold water tank does need to be positioned high enough to create the pressure from gravity for it to work best.

If the mains water pressure supply from your road into your home is low, your system will benefit from replacing the cylinder with a vented cylinder. This way gravity can help create a better water pressure. A vented hot water cylinder can either be heated directly by an immersion heater in the cylinder or indirectly by a boiler. A lot of UK homes rely on a gas boiler to indirectly heat the water but still have an immersion heater as a backup in case of a boiler breakdown.

Cost to install a vented hot water cylinder

Can I fit a pump on a vented cylinder?

If your vented hot water system is struggling to maintain pressure, it is possible to fit an electric pump to the vented cylinder. A heating engineer can fit a shower pump to the system to improve the water pressure from a gravity system.

When it comes to improving the pressure and fitting a pump, there are numerous options of pump styles to be fitted to the water supply;

  • Small twin-impeller pump for a single shower
  • Larger pump to supply better water pressure to all of the taps in a bathroom, not just the shower
  • Centrifugal pump to supply the entire home with a stronger water pressure

How much will it cost to install a vented hot water cylinder?

Replacing a vented hot water cylinder is not too expensive a job. Including the cylinder and labour, this could cost from £500 because if replacing” like-for-like”, the job may be able to be completed in less than 3 hours. The more complicated the job, the longer the heating engineer will need on site but still should only be a day's labour charge to fit a new vented hot water cylinder.

Cost to replace a vented hot water system

Per

Average total labour cost

Replacing a vented hot water cylinder

Per hour

£300

Installing a vented hot water cylinder and replacing pipework

Per hour

£350

Fitting a larger capacity vented hot water cylinder

Per hour

£400

Diagnosing a fault on a vented hot water cylinder

Per hour

£80

How do I know if my vented hot water cylinder needs replacing?

A vented hot water cylinder should last 10 - 15 years before needing replacing. Of course, the length of time depends on how well it has been maintained.

If you start noticing signs of leaks, the cylinder might be cracked or have a pin-hole and may need replacing.

Limescale can build up in the cylinder over the years and this can cause blockages as well as cause the cylinder to not heat effectively or make noises.

If the water from hot taps only is coming out with a smell or discoloured, this could mean that the heat exchanger inside the cylinder has burst and hot water and heating water are mixing. This is dangerous and would mean that the cylinder needs urgent replacing.

Another reason for discoloured or smelly water can be the result of the cylinder's anode rod corroding and that part might need replacing or the entire cylinder replacing.

Which is better, vented or unvented?

When it comes to wondering which out of vented and unvented cylinders is better, vented cylinders require almost no maintenance and are a simpler system to install, therefore often resulting in a cheaper choice. As already mentioned, older UK homes are already plumbed in for vented cylinders so all that is needed is a ‘like for like’ replacement rather than the expense of upgrading plumbing for an unvented system.

Other advantages of vented systems include;

- If the roads water supply is cut off, then the header tank should have a full supply of water, keeping you going until the roads water supply is fully restored

and

- Consistent water pressure and supply when mains pressure is low due to high demand

The only major downside is the space needed for the header tank in the loft.

Of course, unvented systems have their advantages too, mains pressure hot water will generally have a better flow rate (provided the mains supply is strong) and youn gain space without needing the tank in the loft.


Estimates for common heating engineer jobs;

Rates for other trades

Fit or replace a vented hot water cylinder cost in the UK
Fit or replace a vented hot water cylinder cost in the UK (excluding VAT or callout charges)
Location in UKFit or replace a vented hot water cylinder cost
Fit or replace a vented hot water cylinder near Aberdeen£320
Fit or replace a vented hot water cylinder near Amber Valley£274
Fit or replace a vented hot water cylinder near Angus£300
Fit or replace a vented hot water cylinder near Arun£306
Fit or replace a vented hot water cylinder near Ashfield£271
Fit or replace a vented hot water cylinder near Aylesbury Vale£308
Fit or replace a vented hot water cylinder near Barnsley£265
Fit or replace a vented hot water cylinder near Basildon£294
Fit or replace a vented hot water cylinder near Basingstoke & Deane£315
Fit or replace a vented hot water cylinder near Bassetlaw£276
Fit or replace a vented hot water cylinder near Bath & North East Somerset£297
Fit or replace a vented hot water cylinder near Bedford£315
Fit or replace a vented hot water cylinder near Belfast£258
Fit or replace a vented hot water cylinder near Birmingham£268
Fit or replace a vented hot water cylinder near Blackburn£263
Fit or replace a vented hot water cylinder near Blackpool£279
Fit or replace a vented hot water cylinder near Bolton£278
Fit or replace a vented hot water cylinder near Bournemouth£303
Fit or replace a vented hot water cylinder near Bracknell Forest£324
Fit or replace a vented hot water cylinder near Bradford£266
Fit or replace a vented hot water cylinder near Braintree£292
Fit or replace a vented hot water cylinder near Breckland£272
Fit or replace a vented hot water cylinder near Bridgend£260
Fit or replace a vented hot water cylinder near Brighton£301
Fit or replace a vented hot water cylinder near Bristol£289
Fit or replace a vented hot water cylinder near Broadland£299
Fit or replace a vented hot water cylinder near Broxtowe£269
Fit or replace a vented hot water cylinder near Bury£275
Fit or replace a vented hot water cylinder near Caerphilly£262
Fit or replace a vented hot water cylinder near Calderdale£262
Fit or replace a vented hot water cylinder near Cambridge£308
Fit or replace a vented hot water cylinder near Canterbury£283
Fit or replace a vented hot water cylinder near Cardiff£268
Fit or replace a vented hot water cylinder near Carmarthenshire£230
Fit or replace a vented hot water cylinder near Charnwood£257
Fit or replace a vented hot water cylinder near Chelmsford£290
Fit or replace a vented hot water cylinder near Cheltenham£340
Fit or replace a vented hot water cylinder near Cherwell£318
Fit or replace a vented hot water cylinder near Chester£258
Fit or replace a vented hot water cylinder near Colchester£286
Fit or replace a vented hot water cylinder near Conway£247
Fit or replace a vented hot water cylinder near Coventry£265
Fit or replace a vented hot water cylinder near Crewe & Nantwich£271
Fit or replace a vented hot water cylinder near Dacorum£317
Fit or replace a vented hot water cylinder near Derby£259
Fit or replace a vented hot water cylinder near Doncaster£278
Fit or replace a vented hot water cylinder near Dover£268
Fit or replace a vented hot water cylinder near Dudley£269
Fit or replace a vented hot water cylinder near Dumfries & Galloway£278
Fit or replace a vented hot water cylinder near Dundee£302
Fit or replace a vented hot water cylinder near East Ayrshire£243
Fit or replace a vented hot water cylinder near East Devon£275
Fit or replace a vented hot water cylinder near East Dunbartonshire£314
Fit or replace a vented hot water cylinder near East Hampshire£305
Fit or replace a vented hot water cylinder near East Hertfordshire£312
Fit or replace a vented hot water cylinder near East Lindsey£250
Fit or replace a vented hot water cylinder near East Riding£239
Fit or replace a vented hot water cylinder near Eastleigh£311
Fit or replace a vented hot water cylinder near Edinburgh£297
Fit or replace a vented hot water cylinder near Elmbridge£324
Fit or replace a vented hot water cylinder near Epping Forest£324
Fit or replace a vented hot water cylinder near Erewash£261
Fit or replace a vented hot water cylinder near Exeter£284
Fit or replace a vented hot water cylinder near Falkirk£312
Fit or replace a vented hot water cylinder near Fife£299
Fit or replace a vented hot water cylinder near Flintshire£255
Fit or replace a vented hot water cylinder near Gateshead£290
Fit or replace a vented hot water cylinder near Gedling£266
Fit or replace a vented hot water cylinder near Glasgow£310
Fit or replace a vented hot water cylinder near Gloucester£352
Fit or replace a vented hot water cylinder near Guildford£327
Fit or replace a vented hot water cylinder near Gwynedd£254
Fit or replace a vented hot water cylinder near Halton£272
Fit or replace a vented hot water cylinder near Harrogate£260
Fit or replace a vented hot water cylinder near Havant & Waterloo£296
Fit or replace a vented hot water cylinder near Highland£350
Fit or replace a vented hot water cylinder near Horsham£302
Fit or replace a vented hot water cylinder near Huntingdonshire£309
Fit or replace a vented hot water cylinder near Ipswich£340
Fit or replace a vented hot water cylinder near Isle of Wight£293
Fit or replace a vented hot water cylinder near Kings Lynn & West Norfolk£290
Fit or replace a vented hot water cylinder near Kingston-upon-Hull£240
Fit or replace a vented hot water cylinder near Kirklees£265
Fit or replace a vented hot water cylinder near Knowsley£269
Fit or replace a vented hot water cylinder near Lancaster£293
Fit or replace a vented hot water cylinder near Leeds£262
Fit or replace a vented hot water cylinder near Leicester£258
Fit or replace a vented hot water cylinder near Lisburn£252
Fit or replace a vented hot water cylinder near Liverpool£267
Fit or replace a vented hot water cylinder near London£322
Fit or replace a vented hot water cylinder near Luton£318
Fit or replace a vented hot water cylinder near Macclesfield£274
Fit or replace a vented hot water cylinder near Maidstone£290
Fit or replace a vented hot water cylinder near Manchester£273
Fit or replace a vented hot water cylinder near Mid Bedfordshire£309
Fit or replace a vented hot water cylinder near Mid Sussex£309
Fit or replace a vented hot water cylinder near Middlesbrough£284
Fit or replace a vented hot water cylinder near Milton Keynes£311
Fit or replace a vented hot water cylinder near Neath Port Talbot£268
Fit or replace a vented hot water cylinder near New Forest£306
Fit or replace a vented hot water cylinder near Newbury£310
Fit or replace a vented hot water cylinder near Newcastle-under-Lyme£267
Fit or replace a vented hot water cylinder near Newcastle-upon-Tyne£291
Fit or replace a vented hot water cylinder near Newport£270
Fit or replace a vented hot water cylinder near North Ayrshire£263
Fit or replace a vented hot water cylinder near North East Lincolnshire£275
Fit or replace a vented hot water cylinder near North Hertfordshire£314
Fit or replace a vented hot water cylinder near North Lanarkshire£312
Fit or replace a vented hot water cylinder near North Lincolnshire£252
Fit or replace a vented hot water cylinder near North Somerset£285
Fit or replace a vented hot water cylinder near North Tyneside£288
Fit or replace a vented hot water cylinder near North Wiltshire£334
Fit or replace a vented hot water cylinder near Northampton£307
Fit or replace a vented hot water cylinder near Norwich£293
Fit or replace a vented hot water cylinder near Nottingham£262
Fit or replace a vented hot water cylinder near Nuneaton & Bedworth£264
Fit or replace a vented hot water cylinder near Oldham£275
Fit or replace a vented hot water cylinder near Oxford£319
Fit or replace a vented hot water cylinder near Pembrokeshire£231
Fit or replace a vented hot water cylinder near Perth & Kinross£301
Fit or replace a vented hot water cylinder near Peterborough£315
Fit or replace a vented hot water cylinder near Plymouth£276
Fit or replace a vented hot water cylinder near Poole£302
Fit or replace a vented hot water cylinder near Portsmouth£295
Fit or replace a vented hot water cylinder near Powys£330
Fit or replace a vented hot water cylinder near Preston£274
Fit or replace a vented hot water cylinder near Reading£329
Fit or replace a vented hot water cylinder near Redcar & Cleveland£279
Fit or replace a vented hot water cylinder near Reigate & Banstead£321
Fit or replace a vented hot water cylinder near Renfrewshire£303
Fit or replace a vented hot water cylinder near Rhondda, Cynon, Taff£260
Fit or replace a vented hot water cylinder near Rochdale£276
Fit or replace a vented hot water cylinder near Rochester-upon-Medway£310
Fit or replace a vented hot water cylinder near Rotherham£271
Fit or replace a vented hot water cylinder near Salford£273
Fit or replace a vented hot water cylinder near Salisbury£287
Fit or replace a vented hot water cylinder near Sandwell£267
Fit or replace a vented hot water cylinder near Scarborough£294
Fit or replace a vented hot water cylinder near Scottish Borders£410
Fit or replace a vented hot water cylinder near Sefton£270
Fit or replace a vented hot water cylinder near Sevenoaks£301
Fit or replace a vented hot water cylinder near Sheffield£275
Fit or replace a vented hot water cylinder near Slough£324
Fit or replace a vented hot water cylinder near Solihull£267
Fit or replace a vented hot water cylinder near South Ayrshire£266
Fit or replace a vented hot water cylinder near South Bedfordshire£315
Fit or replace a vented hot water cylinder near South Cambridgeshire£297
Fit or replace a vented hot water cylinder near South Gloucestershire£292
Fit or replace a vented hot water cylinder near South Kesteven£300
Fit or replace a vented hot water cylinder near South Lanarkshire£296
Fit or replace a vented hot water cylinder near South Oxfordshire£320
Fit or replace a vented hot water cylinder near South Somerset£292
Fit or replace a vented hot water cylinder near South Tyneside£290
Fit or replace a vented hot water cylinder near Southampton£309
Fit or replace a vented hot water cylinder near Southend-on-Sea£285
Fit or replace a vented hot water cylinder near St Albans£322
Fit or replace a vented hot water cylinder near St Helens£268
Fit or replace a vented hot water cylinder near Stafford£276
Fit or replace a vented hot water cylinder near Stockport£277
Fit or replace a vented hot water cylinder near Stockton-on-Tees£285
Fit or replace a vented hot water cylinder near Stoke-on-Trent£266
Fit or replace a vented hot water cylinder near Stratford-on-Avon£275
Fit or replace a vented hot water cylinder near Stroud£323
Fit or replace a vented hot water cylinder near Suffolk Coastal£364
Fit or replace a vented hot water cylinder near Sunderland£290
Fit or replace a vented hot water cylinder near Swale£281
Fit or replace a vented hot water cylinder near Swansea£262
Fit or replace a vented hot water cylinder near Tameside£275
Fit or replace a vented hot water cylinder near Teignbridge£280
Fit or replace a vented hot water cylinder near Tendring£321
Fit or replace a vented hot water cylinder near Test Valley£298
Fit or replace a vented hot water cylinder near Thamesdown£341
Fit or replace a vented hot water cylinder near Thanet£292
Fit or replace a vented hot water cylinder near The Wrekin£280
Fit or replace a vented hot water cylinder near Thurrock£298
Fit or replace a vented hot water cylinder near Torbay£278
Fit or replace a vented hot water cylinder near Trafford£277
Fit or replace a vented hot water cylinder near Vale of Glamorgan£266
Fit or replace a vented hot water cylinder near Vale of White Horse£325
Fit or replace a vented hot water cylinder near Vale Royal£253
Fit or replace a vented hot water cylinder near Wakefield£266
Fit or replace a vented hot water cylinder near Walsall£268
Fit or replace a vented hot water cylinder near Warrington£277
Fit or replace a vented hot water cylinder near Warwick£271
Fit or replace a vented hot water cylinder near Waveney£283
Fit or replace a vented hot water cylinder near Waverley£322
Fit or replace a vented hot water cylinder near Wealden£298
Fit or replace a vented hot water cylinder near West Lancashire£271
Fit or replace a vented hot water cylinder near West Lothian£309
Fit or replace a vented hot water cylinder near West Wiltshire£334
Fit or replace a vented hot water cylinder near Wigan£271
Fit or replace a vented hot water cylinder near Windsor & Maidenhead£324
Fit or replace a vented hot water cylinder near Wirral£265
Fit or replace a vented hot water cylinder near Wokingham£323
Fit or replace a vented hot water cylinder near Wolverhampton£268
Fit or replace a vented hot water cylinder near Wrexham Maelor£298
Fit or replace a vented hot water cylinder near Wychavon£295
Fit or replace a vented hot water cylinder near Wycombe£333
Fit or replace a vented hot water cylinder near York£257