Macerator

In plumbing · also called Small-bore pumped WC

A unit fitted behind or beside a WC that grinds the waste and pumps it along a small pipe, so a toilet can go where a gravity drain cannot reach. It needs electricity, and in England the building guidance expects the home to keep a gravity WC as well.

Using Macerator in a plumbing system

Updated

A distinction worth remembering

Work out what each appliance discharges, which trap suits its route and how deep a seal it starts with. Then ask what could pull that seal out: its own flow, another appliance's flow, or a long spell with nobody using it.

Questions to take further

Why does my sink smell of drains?
Often the trap has lost its water, through siphonage, evaporation from an outlet nobody uses, or a slow leak. Running the tap refills it; if the smell keeps coming back, the venting or the pipe layout may need looking at.

Sources

  • GOV.UK: Approved Document H — Guidance for England on above-ground drainage, traps, venting, access and rainwater disposal; guidance is not itself the legislation.

Where Macerator fits in the learning path

The Above-Ground Sanitation and Drainage section covers these topics:

  • Sanitary Appliances and Traps
  • Waste and Soil Pipework
  • Blockages, Drains and Sewers

See every plumbing topic

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The main vertical pipe that carries waste from toilets and other appliances down to the underground drain. Its top usually continues up into open air, or ends in an air admittance valve, so that air can get in and the water in the traps is not sucked out as waste rushes down.

Open a meaning to compare its role with Macerator, or follow its full entry.

Soil stack — Soil and vent pipe

The main vertical pipe that carries waste from toilets and other appliances down to the underground drain. Its top usually continues up into open air, or ends in an air admittance valve, so that air can get in and the water in the traps is not sucked out as waste rushes down.

Read the Soil stack entry

Before you start: some plumbing work is regulated or notifiable

Some water fittings work needs notice to, and consent from, the water supplier before it starts. Check the rules where you live.

Gas work is for competent workers covered by a Gas Safe registered business in Great Britain. Northern Ireland has separate gas regulations. Do not work on gas pipes or appliances yourself.

In England, installing an unvented hot-water system over 15 litres is notifiable building work: use a competent installer registered with a competent-person scheme, or tell building control before work starts. Leave this work to a suitably skilled person.

Wales, Scotland and Northern Ireland have their own water and building rules; check which apply before work starts. Electrical connections belong with an electrician.

This guide does not qualify you or make you competent, approved or registered for plumbing, gas or unvented work.

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Macerator Meaning in UK Plumbing | TradeTraining