How Do I Detect a Gas Leak? 

A simple UK homeowner’s guide to identifying gas leaks safely

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Gas leaks are one of the most serious hazards you can face in a property. Even a small leak can put your home at risk of fire, carbon monoxide exposure or significant health issues. Learning how to spot early warning signs is essential for keeping your home and family safe. 

This guide explains the key signs of a gas leak, how to confirm one safely and what to do next. 

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Common Warning Signs of a Gas Leak

Identifying the symptoms early can prevent a dangerous situation from escalating.

1

Smell of Gas

Gas in the UK is given a strong sulphur-like smell to make leaks easier to detect. If you notice a rotten egg smell, it is often the clearest warning sign.

2

Hissing or Whistling Sounds

Gas escaping through damaged pipework may produce a faint hiss. This is often heard near boilers, cookers, meters or outdoor pipe joints.

3

Gas Appliances Behaving Abnormally

Look out for:

• Burners producing yellow flames instead of blue
• Pilot lights blowing out
• Sooty marks around appliances

These can indicate incomplete combustion caused by a gas or ventilation issue.

4

Physical Symptoms

You may experience:

• Headaches
• Dizziness
• Fatigue
• Nausea

Symptoms often worsen indoors and improve once you step outside

5

Dying Plants

A gas build-up can affect oxygen levels in soil. Suddenly dying houseplants can sometimes point to a leak nearby.

Common Causes of Gas Leaks in UK Homes

Most leaks occur because of one of the following:

• Corroded or ageing pipework
• Poorly installed gas appliances
• Faulty boilers
• Loose connections
• Damage caused during building work

How Mr Leak Can Support You

Gas leaks often reveal wider property issues like hidden pipe damage, moisture build-up or structural movement.

 While gas work must always be handled by Gas Safe engineers, Mr Leak can assist with property diagnostics, hidden moisture concerns and tracing pipework faults using non-destructive methods. 

You can learn more about our inspection process on our Leak Detection Service page: 

We also work closely with trusted Gas Safe engineers across the UK, meaning we can help identify the source of a problem before damage becomes costly. 

If you suspect a gas leak, prioritise safety and act immediately. Fast action protects your home, your health and your family.