Gas Heater Not Heating? Here’s What to Do

There’s nothing worse than getting home from work on a cold winter's evening, only to find your gas heater not heating. Giving you absolutely nothing. No warm air, no cosy heat, just the realisation your heating system has decided to stop working when you need it most.

A gas heater not heating can happen for many reasons. Some of these reasons are relatively easy to address. However, others are more serious and need professional help.

In Australia, there are strict rules governing who can work on gas appliances. While you can safely check a few basics, you’ll need to leave many repairs to a licensed technician.

Let’s go through the common reasons, some safe checks you can do yourself, and when to call in the big guns for a professional solution.

Common Gas Heater Problems

Before we explore specific troubleshooting steps in greater detail, it pays to understand why you might find your gas heater not heating to begin with. Many of these common problems can develop gradually, especially in older gas heating systems that don’t get regular maintenance.

Some of the most prevalent issues include:

• Pilot light issues or a faulty thermocouple.
• Dirty air filters that restrict airflow.
• Clogged burners or blocked access panels.
• Thermostat problems or incorrect temperature settings.
• Electrical issues, such as a tripped circuit breaker.
• Low levels of natural gas or LPG.
• Gas leaks or damaged gas lines.

Identifying and getting on top of these potential problems ASAP means that you can take action before your heating system stops working completely or becomes a safety hazard.

Check the Gas Supply and Gas Valve

Before you do anything, make sure your gas heater actually has fuel to burn. If you’re on a mains supply, check the gas valve is open and the supply can flow uninterrupted.

If you’re on LPG, check that the cylinder isn’t empty and the connections are secure. In many cases where someone finds their gas heater not heating, the problem lies with a turned-off valve, low gas levels or a gas line issue.

If you smell gas or hear a hissing noise, turn the heater off, shut off the gas supply and call 1800 GAS LEAK (1800 427 532). A gas leak is a serious safety and health risk, which means that only a licensed gas fitter can resolve the issue.

Check the Pilot Light and Thermocouple

Many older heaters and gas log fires use a pilot light to ignite the burner. If the pilot light won’t stay lit, the thermocouple might be faulty. This is the safety device that turns off the gas if the flame goes out. An accumulation of dirt or soot, a worn-out thermocouple or airflow issues can all cause pilot light problems.

If your pilot light has gone out, always follow the manufacturer’s instructions to get it back into action. This usually involves opening the access panel, turning the gas control knob to “pilot”, pressing it in and lighting the flame. If it won’t stay lit or keeps going out, stop trying and book a gas heater service from a licensed technician.

Assess the Power Supply and Thermostat Settings

Gas heaters still need electricity for ignition, fans and controls. So it might come as a surprise, but electrical issues can actually be the cause of your gas heater not heating.

It’s well worth checking your power supply first, as a tripped circuit breaker, blown fuse or faulty power point can stop a heater from working. If you have a battery-operated thermostat, replace the batteries and see if that solves the problem.

Incorrect thermostat settings are another common problem. If you have the temperature set too low, your heater may not turn on at all. Some thermostat issues can also cause short cycling, where the heater turns on and off too often, and your home never reaches the right temperature.

Common Maintenance-Related Issues to Check

While you should always leave repairs to the experts, there are a few safe basic checks you can do yourself if you find your gas heater not heating as it should:

• Dirty return air filters obstructing airflow and lowering energy efficiency in ducted heating systems.
• Strange noises or unusual sounds indicating a mechanical fault.
• Yellow flame instead of blue (this can point to a combustion issue).
• Low LPG cylinder levels for portable or bottle-fed heaters.
• Clogged burner or debris blocking the flame.
• Loose electrical connections inside the access panel

It’s important that you DO NOT attempt to address the last two points in this list yourself. When it comes to accessing the internal burners or touching internal electrical wires and connections, always leave that to a licensed technician as per Australian Standard AS 4575 requirements.

These are some of the most common issues that stop heaters from producing warm air. Regular maintenance, including cleaning or replacing filters, can prevent many of them.

Why You Must Always Use a Licensed Technician

In Australia, only a licensed gas fitter can carry out any work involving a gas line, burner or internal heater components. That means repairing or replacing a faulty thermocouple, fixing pilot light issues beyond basic cleaning, repairing a gas leak or replacing burners is never a DIY job.

Australian standards and regulators require licensed gasfitters to test and certify work (e.g. provision of certificates of compliance for all gas-related works).

It’s well worth booking a professional gas heater service once every two years, or yearly for older systems. Licensed technicians do more than merely keep your heater working correctly. They will also check for carbon monoxide leaks, faulty electrical components and other potential issues that could put your health at risk.

Working on gas appliances without a licence can result in fines, voided manufacturer warranties and serious safety hazards. It can also potentially breach your home and contents insurance policy, which is the last thing that you want if things go pear-shaped due to a gas-related incident.

Repair or Replace? Making the Right Call

Unsure whether it’s worth repairing your heater or time to replace it? If your heater is anywhere between 10 and 20 years old, requires frequent repairs or has efficiency issues, now might be the time to consider an upgrade.

Older systems can have worn-out parts, produce low heat output and incur higher running costs. In some cases, the cost of repairs can quickly add up. They can even exceed the cost of just biting the bullet and installing a new unit.

Modern gas heaters, split system heating and high efficiency gas log fires often provide better performance, more safety features and lower energy bills. A licensed technician can advise if a repair will keep your heater running smoothly or if replacing it is the better long-term option.

Keep Your Home Warm and Safe

Finding your gas heater not heating can certainly be frustrating, there’s no doubt about that. However, it’s often a sign that something needs attention – whether that’s a quick filter clean or a more serious repair.

You can safely check the basics like your gas supply, pilot light and power connections, but anything involving the gas line, internal components or burner should always be done by a licensed professional.

Want to keep your home warm, comfy and safe over these remaining weeks of winter? Of course you do. And you can do so by providing regular maintenance for your gas heater, fixing minor issues before they become major and upgrading when age starts to take its toll on the heater.

Make sure you avoid complex DIY fixes for your gas supply lines. Search online for a qualified gas technician to keep your heating system working as it should.

Please note: Thanks for reading our blog “Gas Heater Not Heating? Here’s What to Do. ” This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.