Water leak detection in Plymouth
Leak detection in Plymouth finds where water is escaping out of sight in a home: on its hot and cold pipes, on its heating, or on the supply pipe under the garden or path. West Country Leak Detection covers the 9 districts of the Plymouth post town.
- Properties built before 1973
- 66.1%
- VOA, 31 March 2026
- Properties built from 1945 to 1972
- 29.9%
- Against 25.3% across England
- VOA, 31 March 2026
- Households in terraced houses
- 32.8%
- Census 2021
Source: Office for National Statistics, Census 2021, licensed under the Open Government Licence v.3.0
Valuation Office Agency, Council Tax: stock of properties, 2026. Contains public sector information licensed under the Open Government Licence v3.0.
Which PL districts fall within the Plymouth service area?
The Plymouth service area takes in the 9 PL districts of the Plymouth post town, while the rest of Devon is covered on a county page.
- PL1 Plymouth
- PL2 Plymouth
- PL3 Plymouth
- PL4 Plymouth
- PL5 Plymouth
- PL6 Plymouth
- PL7 Plymouth
- PL8 Plymouth
- PL9 Plymouth
Beyond the city the PL area runs on into Devon and Cornwall. Tavistock, Yelverton and Ivybridge appear under leak detection across Devon, and the table of every postcode district covered holds the rest, Cornish towns included.
Which hidden leaks does a Plymouth investigation look for?
A Plymouth investigation searches for one of four kinds of hidden leak: a leak on the hot and cold water pipes, one on the central heating, one on the buried supply pipe, or the leak behind an insurance claim.
The same search words also bring up car leaks and gas leaks. This page concerns water in the pipes of a home, which is what West Country Leak Detection looks for.
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Water leak detection
Peeling paint, a musty smell or a damp patch that keeps spreading indoors sends the search to the hot and cold pipework.
Water leak detection for pipes in walls, floors and ceilings
- Pipe
- Hot and cold water pipework and fittings inside the property
- What points to it
- Damp patches or stains, peeling paint or bubbling wallpaper, a musty smell, running water with every tap off
- Methods
- Acoustic listening, thermal imaging on hot pipes, moisture mapping, pressure testing and tracer gas
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Central heating leak detection
Ideal links frequent topping up, monthly or more for example, to a small leak on the heating or a fault in its pressure relief valve.
Central heating leak detection
- Pipe
- The sealed heating circuit: radiators and their valves, flow and return pipes, underfloor heating loops
- What points to it
- A boiler gauge that keeps falling below 1 bar, damp spots or rust marks around radiators, a wet patch around underfloor heating
- Methods
- Pressure testing, loop by loop for underfloor heating, then thermal imaging or tracer gas
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Underground water leak detection
Damp ground or unusually lush grass along the front path can mark a leak on the buried pipe that feeds the house.
Underground water leak detection
- Pipe
- The supply pipe buried between the property boundary and the house
- What points to it
- A meter dial still moving with the internal stop tap closed, an unexplained rise in a metered bill, wet ground or lush grass outside
- Methods
- Acoustic listening along the pipe's route, and tracer gas where the leak is quiet
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Trace and access
Some insurers send their own specialist and some want to agree the work first, so the policy decides how the search begins.
Trace and access for an escape of water claim
- Pipe
- Water pipes, the central heating or the buried supply pipe, wherever the escaping water starts
- What points to it
- A home insurer asking for the leak's source to be traced before the claim proceeds
- Methods
- The method that suits the pipe, with the leak's position, the access needed, photographs and the cause where known recorded
Which pipe does South West Water look after in Plymouth, and which is yours?
South West Water looks after the main, the communication pipe up to the boundary of the street the main is laid in, the external stop tap and the meter, and a Plymouth homeowner owns the supply pipe from that boundary to the internal stop tap, usually found under the kitchen sink.
Before anyone digs, the meter can show whether water is escaping. South West Water's Leaks page sets out the test in four steps:
- use no water at all for an hour;
- read every dial on the meter, the red numbers included;
- read it again an hour later;
- repeat the whole test with the internal stop tap turned off.
Its code of practice suggests switching off water-using appliances for a couple of hours, and warns that a storage tank filling up can move the dial on its own.
When the leak turns out to be on an underground pipe, South West Water will look for it free for up to thirty minutes and suggest what to do next, then offers a contribution once the repair is confirmed and a subsidy towards replacing the leaking supply pipe within 30 days, the last two for homeowners only. Those are South West Water's schemes, quite apart from West Country Leak Detection. The same 30 days governs the bill: South West Water gives a leak allowance for a supply pipe leak repaired within 30 days of its contact with you about it.
What does the age of Plymouth's homes mean for their supply pipes?
The age of Plymouth's homes makes lead supply pipes a real possibility: two in three properties (66.1%) were built before 1973. South West Water says a home built before 1970 may still have lead pipes or may have had them replaced with copper or plastic.
Post-war building weighs heavily in the city. Of Plymouth's properties, 29.9% date from 1945 to 1972, against 25.3% across England (VOA, 31 March 2026).
Lead on the owner's side of the boundary, in the house or in the supply pipe, is the owner's to replace, South West Water says, unless one of its phased schemes applies. Give South West Water at least four weeks' notice when you replace yours and the company will replace any lead on its own side of the stop tap free of charge.
An old supply pipe that has started leaking can be traced along its route as a leak on the supply pipe and marked before any plaster or paving has to be broken, so the dig and the replacement start in one place.
Which reservoirs supply Plymouth's taps?
Roadford Reservoir, South West Water's largest, gives its name to the zone that supplies Plymouth, where the company runs it together with smaller reservoirs, river intakes and groundwater, and Roadford also supports abstraction from the River Tamar.
Treatment moved north of the city in November 2020, when the Mayflower works at Roborough took over from the old works at Crownhill, which had served Plymouth since the 1950s. South West Water's 2025 water quality reports also name Dousland treatment works for several Plymouth zones.
South West Water's postcode search classes the city's water as soft, checked at PL1 3BJ.
How do you report a leak to South West Water in Plymouth?
Report a leak in Plymouth on South West Water's Leaks page, which takes reports through an online form, WhatsApp or social media.
Indoors the rules change. South West Water's code of practice says it does not get involved with a leak inside the home: it cannot help with or cover the cost of the repair, and no leak allowance applies. A leak behind a Plymouth wall or under a floor is the homeowner's to trace, and the investigations above set out how West Country Leak Detection goes about it.