Plumber in Pinner

Plumbing in Pinner: what is different here

How hard is the water in Pinner, and what does it do?

Hard enough to shape most of our plumbing visits here. Affinity Water supplies HA5, and its 2025 reports for the supply zones around Pinner give total hardness of 360 mg/l for Harrow North, 348 mg/l for Northwood and 268 mg/l for Rayners Lane. Which zone your street is in depends on the address, and Affinity's hardness checker will tell you. At those levels scale collects on the cartridges in thermostatic shower valves, on WC fill valves, on immersion elements and on the heat exchangers of combination boilers.

The usual symptom is a shower that runs hot then cold, or a toilet cistern that keeps trickling. Most of the time the fix is a descale or a replacement cartridge rather than a new valve. If you are planning a new bathroom or a cylinder, ask us to check the manufacturer's water-treatment requirements at the quote stage, because some warranties depend on them.

Who fixes a blocked drain shared with next door?

Often not you. Over half of the homes in Pinner South ward are semi-detached, and many interwar pairs drain into one pipe before reaching the sewer in the road. Thames Water, which runs the sewers here, says it is responsible for drains shared with neighbours, even under your garden or driveway, while each owner looks after the pipe that serves only their house. Affinity supplies the water, but the sewers are Thames Water's.

So when a gully or a ground-floor toilet backs up, the first job is working out where the blockage sits. If it is on your own branch, we clear it. If it is on the shared run or beyond, we tell you so and you can report it to Thames rather than paying for work on their pipe. We do not carry out CCTV drain surveys; where one is needed, we say so.

What changes in Pinner's larger detached houses?

The amount of pipe. Detached houses account for 29.1% of homes in Pinner ward, which takes in Pinner Green and Pinner Hill, and 34.2% in Hatch End ward, far above the Harrow share of 11.3%. Those houses tend to have more than one bathroom, an en suite added during a loft or rear extension, outside taps on two sides and sometimes a utility room or garden building with its own supply.

A pressure drop or a slow leak can come from any of them. We work methodically: isolate sections, check what the meter does, and trace the run before lifting floors. If there is stored hot water, we check the cylinder and its controls while we are there. Any gas work goes to a Gas Safe registered engineer; we do not service or repair boilers.

Leaks between flats in Pinner's managed blocks

Purpose-built flats house 29.3% of Pinner ward's households. When water comes through a ceiling, the lease decides who pays: pipes serving one flat usually belong to that flat, while risers and shared stacks are often the freeholder's, handled through the managing agent. We find the source first, whether a waste joint, failed bath sealant, a pushed-on fitting or a communal pipe, and photograph it before and after.

If it is communal, you get a short written note for the agent. Flats over the village-centre shops add one complication: access is usually through a rear yard, and the bays at the front are controlled parking, so tell us where we can unload.

Bathrooms in listed and conservation-area houses

Inside an ordinary Pinner semi, a new bathroom needs no planning permission. In a listed building, such as the timber-framed houses on the High Street or Waxwell Lane, consent is needed even for interior changes if they touch what makes the building special, and new pipe runs through old timber framing can count. Tell us if the house is listed before we survey, and we will plan the routes around what the council is likely to accept, or ask you to check first.

In Pinnerwood Park, a new soil vent or flue on the front elevation can also be a planning matter. Showers are tanked before tiling, and most bathrooms are tiled in two to three days once the plumbing is in.

Official sources

• Affinity Water: Harrow North supply zone (AF056) water quality report, 2025
• Affinity Water: Northwood supply zone (AF048) water quality report, 2025
• Affinity Water: Rayners Lane supply zone (AF055) water quality report, 2025
• Thames Water: sewer pipe responsibility
• ONS Census 2021 via Nomis: accommodation type (TS044), Pinner, Pinner South and Hatch End wards and Harrow
• Harrow Council: listed buildings
• Harrow Council: Pinner High Street conservation area appraisal and management strategy

Last reviewed October 2026 by EliteShires Property Services.