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Plumbing

Plumbing small works estimate.

Plumbing small works cover everything from fixing a dripping tap to swapping a boiler or installing a new bathroom. This guide breaks down the most common jobs and the costs that catch plumbers out.

Authored by Alexandr Vreme & Maksym Vasylkov
Published July 2026 — Next review July 2027

Who this guide is for

This guide is for plumbers, heating engineers, and maintenance contractors pricing small to medium plumbing and heating works in domestic properties.

Information needed

• Type of work: new installation, like-for-like swap, or trace-and-repair
• Access — loft space, under-floor crawl, cupboard clearance for boiler
• Existing pipework condition and material (copper, plastic, lead)
• Boiler location and gas supply capacity (meter size, pipe run length)
• Flue route for boiler or unvented cylinder
• Is the property occupied? — affects working hours and dust/noise management

Typical jobs and price ranges

• Boiler swap (like-for-like, combi): £1,800–2,800 including commissioning
• New bathroom installation (pipework only, no tiling): from £4,000
• Additional radiator, including pipework run: £250–500 each
• Powerflush: £400–700
• Leak trace-and-repair: £200–800 depending on access
• Unvented cylinder installation: £1,500–2,500

Pricing methods

Plumbers typically use one of three pricing approaches:

• Daywork rates — £200–350 per day plus materials, for work with unknown scope
• Fixed price — with a clear allowance for hidden defects encountered during the job
• Per point — a set rate per radiator, per outlet, or per appliance, common for new-build and extension work

Commonly missed costs

• Making good — is it included or a separate tradesperson?
• Upgraded gas pipe to meet new boiler demands
• Magnetic filter and system additive (inhibitor) on boiler swaps
• TRVs and lockshield valves on every radiator
• Commissioning, benchmarking, and notification to building control (unvented cylinders, gas)
• Scaffolding for flue access on upper-floor boiler locations

Miniature worked example

Unvented cylinder replacement (existing location, direct swap):

• Cylinder (250 L, standard): £800
• Fitting labour (1.5 days): £600
• Pipework alterations and new expansion vessel: £300
• Commissioning and certification: £150
• Total: £1,850

Questions to ask

• Is the property under a warranty or insurance claim that restricts who can do the work?
• Does the Gas Safe registered engineer need to notify building control?
• Is there an existing system bypass, or does one need to be installed?
• What is the water mains pressure and flow rate (for unvented, showers, and multi-outlet baths)?
• Are there any asbestos-containing materials (ceilings, pipe lagging) that affect access?