Smells Like Gas But Can't Find a Leak? What to Do

Smelling gas is always concerning, even if you can't locate the source. This guide explains what to do, what causes gas-like smells, and when you need emergency help.

First: Is It Actually a Gas Leak?

Signs of a Real Gas Leak

• Strong, distinctive rotten egg/sulphur smell
• Smell gets stronger near gas appliances or pipes
• Hissing sound near gas fittings
• Dead plants near gas lines
• Bubbles in standing water near pipes

Take Immediate Action If You Suspect a Leak

DO:

1. ✓ Open all doors and windows
2. ✓ Turn off gas supply at meter (if safe to do so)
3. ✓ Leave the property
4. ✓ Call National Gas Emergency: 0800 111 999
5. ✓ Wait for engineer before returning

DON'T:

1. ✗ Turn any electrical switches on or off
2. ✗ Use mobile phones indoors
3. ✗ Smoke or use naked flames
4. ✗ Look for leak with a lighter
5. ✗ Ignore the smell

Common Gas-Like Smells That Aren't Gas Leaks

1. Sewer Gas

Smells Like: Rotten eggs, similar to natural gas

Causes:

• Dry P-traps under sinks/showers
• Blocked or damaged drain vents
• Cracked sewer pipes

How to Tell:

• Smell strongest in bathroom/kitchen
• Running water temporarily reduces smell
• Smell absent near gas appliances

The Fix: Run water in all drains to refill traps. If persists, drainage inspection needed.

2. Dead Animals

Smells Like: Rotten, decomposing (can be mistaken for gas)

Common Locations:

• Cavity walls
• Under floorboards
• In loft spaces
• Behind kitchen units

How to Tell:

• Smell localised to one area
• Gets worse over 1-2 weeks then fades
• No connection to gas appliances

The Fix: Locate and remove. May need pest control or builder.

3. Stale Pilot Light Smell

Smells Like: Light gas smell when boiler/fire starts up

Why It Happens:

• Small amount of unburnt gas before ignition
• Normal for older appliances
• Should disappear within seconds

When to Worry: If smell persists or is strong, have appliance checked.

4. Electrical Burning

Smells Like: Can have sulphur-like quality (some describe as gas-like)

Causes:

• Overheating wiring
• Burning insulation
• Faulty outlets

Danger: Fire hazard - investigate or call electrician.

5. Sulphur from Well Water

Smells Like: Rotten eggs from tap water

Why: Bacteria in water supply produces hydrogen sulphide

How to Tell:

• Smell only when running water
• Not present near gas appliances

6. Garbage/Organic Waste

Smells Like: Rotting, can mimic gas smell

Sources:

• Kitchen bin
• Compost
• Food waste in drains
• Forgotten food behind appliances

7. New Appliances Off-Gassing

Smells Like: Chemical, sometimes mistaken for gas

Why: New appliances emit chemicals when first heated

Normal For:

• New boilers
• New cookers
• Heating elements

Usually fades after a few uses.

How to Locate a Gas Smell Source

Safe Investigation Steps

1. Open windows first for ventilation

2. Follow your nose

   • Where is smell strongest?
   • Near gas appliances?
   • Near drains?

3. Check obvious sources

   • Cooker hob (burner not fully off?)
   • Pilot lights
   • Gas fire connections

4. Check P-traps

   • Run water in all drains for 30 seconds
   • Does smell reduce?

5. Look for visual clues

   • Dripping water from boiler
   • Discoloration on walls
   • Dead plants

Don't Do This

• Never use matches or lighters to find leaks
• Don't try to tighten gas fittings yourself
• Don't ignore persistent smells

When to Call the Gas Emergency Line

Call 0800 111 999 immediately if:

• Strong, persistent gas smell
• Smell near gas appliances or pipework
• Anyone feeling unwell (headache, dizziness)
• Hissing sound near gas supply
• You're unsure of the source

This service is free and available 24/7.

After a Gas Emergency Visit

If the National Grid finds a leak, they'll:

• Make the situation safe
• Disconnect faulty appliances if needed
• Give you a report

You'll then need to:

• Arrange repairs by a Gas Safe registered engineer
• Get reconnection when repairs complete
• Have safety check before using gas again

Prevention Tips

• Annual boiler service - Catches small issues early
• Check appliances regularly - Look for damage, discoloration
• Know your smell - Understand what normal gas smells like
• Install CO detector - Carbon monoxide is odourless but deadly
• Run drains monthly - Keeps P-traps full

Professional Gas Safety Checks

If you're concerned about your gas supply or appliances, our Gas Safe engineers can conduct a full safety inspection.

Plumbers Glasgow Ltd:

• Call: +44 141 468 9930
• Gas safety inspections
• Appliance safety checks
• CP12 landlord certificates

Emergency Numbers:

• Gas Emergency: 0800 111 999
• Fire Service: 999
• Carbon Monoxide concerns: 999

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Related Services:

• Gas Safety Certificate Glasgow
• Gas Engineer Glasgow
• Drainage Services Glasgow

Related Articles:

• Gas Leak Emergency
• Boiler Making Noise?