How to locate a leak in central heating system

If your central heating system is sealed or inaccessible you will have to contact a professional plumber or heating engineer to identify where the system is leaking. Otherwise, read this simple guide to understand some of the methods you can use to identify the source of a leak in a central heating system.

Level of difficulty

Level 1: Beginner

What you need

  • Incense stick
  • Coloured paper

The steps to follow

  1. Start by inspecting your boiler and all pipe-work.
  2. If you spot a wet patch, it's most likely to be the source of the leak.
  3. Leaks can also be easily spotted by just looking thoroughly. Look for corrosion, rust or water stains, or evidence of coloured mineral salts forming on the pipes.
  4. You can also use coloured paper to locate leaks. Place coloured paper along the pipes of the central heating system. If there's a leak at that particular spot, the coloured paper will stain.
  5. You can locate minor gas leaks with an incense stick. Walk close to the pipes holding the lighted incense stick and the smoke from the stick will move when placed near the source of the leak. Gas leaks are dangerous - if you suspect one, call an emergency heating engineer straight away or the National Grid on 0800 111 999.

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