Pilot Light Keeps Going Out on Gas Hot Water: Common Causes

If the pilot light keeps going out on your gas hot water system, it usually points to a gas supply, thermocouple, burner, flue, draught or appliance safety issue. It is not something to keep relighting over and over. A licensed gasfitter should inspect the system, test the gas pressure, check the burner operation and confirm the appliance is safe to use.

For homeowners in Brisbane, Gold Coast, Logan, Ipswich, Redlands and surrounding South East Queensland areas, pilot light problems are common on older gas storage hot water systems, especially when the unit is exposed to wind, rain, corrosion or ageing internal components.

Quick Answer

A gas hot water pilot light may keep going out because of:

• A faulty thermocouple

• Dirty or blocked pilot assembly

• Wind or draught blowing out the flame

• Low gas pressure

• LPG regulator issues

• Water damage or corrosion inside the burner chamber

• Faulty gas control valve

• Blocked or restricted flue

• Appliance age and general wear

• Incorrect gas type or supply issue

If you smell gas, hear gas escaping, or the system will not stay lit after following the manufacturer’s basic relighting instructions, stop using it and book a licensed gasfitter. JR Gas & Water provides gas hot water, gas fitting and hot water repair services across Greater Brisbane and the Gold Coast.

Why the Pilot Light Matters

The pilot light is the small flame that keeps older gas storage hot water systems ready to heat. When the water temperature drops, the main burner lights from the pilot flame and heats the tank.

If the pilot light goes out, the hot water system cannot operate. The issue may be simple, but it can also be a sign that the appliance is shutting itself down for safety reasons.

That is why the cause needs to be checked properly instead of guessing.

Common Causes of a Gas Hot Water Pilot Light Going Out

1. Faulty Thermocouple

The thermocouple is a safety device that confirms the pilot flame is actually burning. If it cannot detect the flame properly, it shuts off the gas supply to stop unburnt gas from escaping.

A failing thermocouple may cause the pilot to light briefly, then go out as soon as you release the control button.

Common signs include:

• Pilot lights but will not stay on

• Pilot goes out after a few seconds

• Hot water system works sometimes, then fails again

• Older system has not been serviced in years

A thermocouple is a safety component, not just a convenience part. It should be checked and replaced by a licensed gasfitter where required.

2. Dirty Pilot Assembly

Dust, insects, rust flakes, lint and debris can restrict the pilot flame. If the flame is weak, unstable or not hitting the thermocouple properly, the system may shut down.

This is more common when the hot water system is:

• Installed outside

• Exposed to wind and rain

• Close to gardens, mulch or insects

• Older and corroding internally

• In a dusty or coastal environment

A licensed gasfitter can clean and test the pilot assembly, burner and flame pattern as part of a gas hot water inspection.

3. Wind or Draught Blowing Out the Flame

Outdoor gas hot water systems can be affected by wind, especially if the burner area, access panel or installation location allows strong draughts through the unit.

This may happen on homes with:

• Exposed side passages

• Open rear yards

• Coastal wind exposure on the Gold Coast

• Units installed near corners of buildings

• Poorly fitted access covers

• Older external gas storage units

The answer is not to block vents or cover the appliance. Gas appliances need correct ventilation and combustion air. Blocking openings can create a dangerous carbon monoxide risk.

4. Low Gas Pressure

If the gas pressure is too low, the pilot flame may be weak or unstable. The main burner may also struggle to operate properly.

Low gas pressure can be caused by:

• Undersized gas pipework

• Faulty LPG regulator

• LPG bottles running low

• Multiple gas appliances running at once

• Natural gas supply issues

• Incorrect appliance setup

• Gas pipe restrictions

Gas pressure must be tested with proper equipment. JR Gas & Water can inspect gas supply issues through its licensed gas fitting services in Brisbane and the Gold Coast.

5. LPG Regulator Problems

For homes running LPG bottles, the regulator controls the gas pressure feeding the appliance. If the regulator is failing, restricted or not suitable, the pilot and burner may not perform correctly.

Possible signs include:

• Pilot flame keeps dropping out

• Hot water works after bottle change, then fails again

• Other LPG appliances also have issues

• Yellow or lazy flame

• Gas smell near the bottles or regulator

• Regulator looks old, damaged or corroded

JR Gas & Water provides LPG gas regulator replacement where the regulator is faulty, non-compliant or no longer suitable.

6. Faulty Gas Control Valve

The gas control valve manages the pilot, main burner and safety operation of the gas hot water system. If it fails, the pilot may not stay lit or the system may not heat correctly.

A gas control valve issue may be suspected when:

• The thermocouple has been checked but the pilot still fails

• The control knob does not operate properly

• The pilot drops out randomly

• The main burner does not light correctly

• The system is older and parts are wearing out

Depending on the age and condition of the unit, replacement of the full hot water system may be better value than major parts replacement.

7. Blocked or Restricted Flue

Gas hot water systems need to remove combustion gases safely. If the flue is blocked, damaged, corroded or restricted, the appliance may not operate safely.

Possible flue issues include:

• Rust or corrosion

• Bird nesting

• Debris in the flue path

• Poor draught

• Incorrect installation

• Damaged flue terminal

A flue issue is not something to ignore. Combustion problems can create serious safety risks, including carbon monoxide exposure.

8. Water Damage or Internal Corrosion

Older gas storage hot water systems can suffer from corrosion around the burner chamber, base, access panels or internal components. If water has leaked into the burner area, the pilot assembly and controls may be affected.

Warning signs include:

• Rust around the bottom of the tank

• Water dripping near the burner compartment

• Pilot repeatedly going out after rain

• System looks swollen, rusted or deteriorated

• Relief valve or tank is leaking

• Hot water system is over 8–10 years old

If the cylinder is leaking or badly corroded, repairing the pilot light may be a waste of money. The real issue may be that the hot water unit is near the end of its life.

JR Gas & Water can inspect the system and advise whether repair or replacement makes more sense. If replacement is needed, you can view gas storage hot water systems or request advice on a suitable alternative.

9. Incorrect Gas Type or Appliance Setup

Natural gas and LPG appliances are not the same. A hot water system must be set up for the correct gas type, with the correct injectors, regulator and pressure.

A pilot or burner issue may occur where:

• An appliance has been changed without correct conversion

• LPG and natural gas have been confused

• The wrong regulator has been fitted

• Gas pressure has not been commissioned correctly

• Appliance data plate does not match the site gas supply

Gas type and appliance setup must be checked by a licensed gasfitter. Guessing can be dangerous.

What Homeowners Can Check First

Before booking a plumber, you can do a few basic non-invasive checks.

You can check:

• Whether other gas appliances are working

• Whether LPG bottles are empty

• Whether the gas isolation valve is open

• Whether there has been recent heavy rain or wind

• Whether the hot water unit is obviously leaking

• Whether there is a gas smell near the unit

• Whether the access panel is loose or missing

• Whether the unit is very old or corroded

You should not remove burner parts, bypass safety devices, adjust gas pressure, modify the flue or keep forcing the system to relight.

What Not To Do

Do not keep relighting the pilot every day and hoping it fixes itself. Repeated pilot failure means the system needs attention.

Do not:

• Tape, jam or hold down the gas control button

• Block ventilation openings

• Cover the appliance to stop wind

• Modify the flue

• Adjust gas pressure yourself

• Pull apart the burner assembly

• Use matches or lighters outside the manufacturer’s relighting process

• Ignore a gas smell

• Keep using the system if it appears unsafe

• Ask a handyman to work on gas components

Gas work in Queensland must be carried out by a licensed gasfitter.

Brisbane and Gold Coast Context

In South East Queensland, pilot light issues are often seen on older external gas storage hot water systems. Brisbane storms, humidity, insects, dust, coastal air on the Gold Coast and general outdoor exposure can all contribute to corrosion and burner problems over time.

In older homes, gas pipe sizing can also be an issue, especially where extra gas appliances have been added over the years. A hot water system, cooktop, oven, heater or BBQ connection may all place demand on the same gas supply.

That is why a proper gasfitting inspection is important. The issue may not be just the hot water unit. It may be the gas supply, regulator, pipe sizing, appliance condition or installation setup.

Repair or Replace?

Whether you repair or replace the system depends on the age, condition and fault.

Repair may make sense if:

• The system is relatively new

• The cylinder is not leaking

• The burner chamber is in good condition

• Parts are available

• The issue is isolated to a serviceable component

• The appliance is otherwise compliant and safe

Replacement may be better if:

• The tank is leaking

• The system is heavily rusted

• The unit is old and unreliable

• Major gas controls are failing

• Parts are expensive or unavailable

• The appliance is non-compliant

• You are already having repeated hot water issues

JR Gas & Water can assess the fault and help compare repair cost against replacement options, including gas, electric and heat pump hot water systems.

When to Call a Gasfitter Immediately

Book a licensed gasfitter urgently if:

• You smell gas

• The pilot will not stay lit

• The flame is yellow, lazy or unstable

• The unit makes banging or delayed ignition sounds

• The hot water system is leaking

• The burner area is rusted or damaged

• The system shuts down repeatedly

• There are signs of heat damage

• You are unsure whether the appliance is safe

For suspected gas leaks, JR Gas & Water provides gas leak repair services across Brisbane and Gold Coast service areas.

How JR Gas & Water Can Help

JR Gas & Water can inspect gas hot water systems, test gas pressure, check pilot and burner operation, assess regulators, identify compliance issues and advise whether repair or replacement is the better option.

Depending on the issue, JR Gas & Water can assist with:

• Gas hot water fault finding

• Pilot light and burner issues

• Thermocouple and gas control checks

• LPG regulator replacement

• Gas pressure testing

• Gas leak testing

• Gas compliance inspections

• Hot water system replacement

• Natural gas and LPG appliance checks

You can book a minimum attendance and diagnostic service call or request pricing through the JR Gas & Water quote and booking page.

FAQs

Why does my gas hot water pilot light keep going out?

The most common causes are a faulty thermocouple, dirty pilot assembly, draught, low gas pressure, LPG regulator fault, blocked flue or failing gas control valve. A licensed gasfitter needs to test the appliance to confirm the cause.

Can I relight the pilot myself?

You can follow the manufacturer’s basic relighting instructions if it is safe to do so and there is no gas smell. If the pilot keeps going out, stop relighting it and book a licensed gasfitter.

Is a pilot light going out dangerous?

It can be. The appliance may be shutting down because a safety device has detected a problem. Repeated pilot failure, gas smell, yellow flames or burner issues should be treated seriously.

Does wind cause gas hot water pilot lights to go out?

Yes, wind and draught can blow out a weak or exposed pilot flame, especially on older outdoor gas storage hot water systems. The solution is not to block vents or cover the appliance. The installation and burner operation need to be checked safely.

How do I know if the thermocouple is faulty?

A common sign is the pilot lighting while the control button is held down, then going out when the button is released. A gasfitter can test and replace the thermocouple if required.

Can low gas pressure affect the pilot light?

Yes. Low gas pressure can cause a weak pilot flame and poor burner operation. The gas supply, pipe sizing, regulator and appliance pressure need to be tested with proper equipment.

Should I repair or replace my gas hot water system?

If the system is newer and in good condition, repair may be worthwhile. If it is old, leaking, corroded or has repeated gas control issues, replacement may be better value.

Can JR Gas & Water issue a gas compliance certificate?

JR Gas & Water can complete gas compliance assessments and issue certification where the installation is compliant. If defects are found, they must be rectified before certification can be provided. You can view the gas compliance assessment and certificate service for more information.

Final Word

A pilot light that keeps going out is not just an inconvenience. It can point to a safety device, gas pressure issue, burner fault, regulator problem, flue restriction or ageing hot water system.

Do not keep forcing the system to relight. If your gas hot water pilot light keeps going out, book a licensed gasfitter to test the appliance properly and confirm whether it can be repaired safely.

JR Gas & Water can inspect, repair and replace gas hot water systems across Greater Brisbane, Gold Coast and surrounding South East Queensland service areas.