1. The Grill Is Not Getting Enough Fuel

A low or inconsistent fuel supply is one of the first things to consider when a gas grill won’t stay lit.

With a propane grill, the cylinder may be nearly empty. With a natural-gas grill, there may be an issue affecting the amount of gas reaching the appliance.

A grill can sometimes ignite even when the available fuel flow is marginal. Once the burners begin demanding more gas, however, the flame may weaken and eventually go out.

Possible signs include:

• Very small burner flames.
• Slow preheating.
• The flame weakens when another burner is turned on.
• The grill cannot reach its normal cooking temperature.

If your grill stays lit but produces poor heat, see our guide on why a gas grill is not getting hot.

2. A Propane Regulator May Be Restricting Gas Flow

Propane grills rely on a regulator to control gas pressure between the propane cylinder and the grill.

If gas flow becomes restricted, the grill may still ignite but operate with unusually weak flames. In some cases, the burners may eventually go out because there is not enough gas flow to maintain combustion.

Homeowners sometimes describe this as the grill being stuck in a low-flame or low-flow condition.

Possible symptoms include:

• All burners have weak flames.
• The grill suddenly takes much longer to heat.
• Adding another burner causes the existing flames to weaken.
• The grill worked normally before a propane-cylinder change and now performs poorly.

Because the regulator is part of the fuel system, it should not be modified, bypassed or repaired with makeshift parts. The U.S. Consumer Product Safety Commission’s gas grill safety guidance also recommends inspecting gas hoses and connections and not using a grill when a gas leak is present.

3. Dirty or Clogged Burners Can Cause an Unstable Flame

A burner does more than simply release gas. It must distribute fuel evenly through many small burner ports while mixing it with the correct amount of air.

Grease, rust, food residue, insects and other debris can interfere with those burner ports.

When enough openings become restricted, the flame pattern may become uneven or unstable. In severe cases, part of the burner may light while another section repeatedly goes out.

Common symptoms include:

• Only part of the burner stays lit.
• The flame moves unevenly across the burner.
• The burner repeatedly goes out in the same area.
• The grill heats unevenly.
• The flames have changed color or appearance.

Learn more about BBQ burner cleaning, repair and replacement.

4. The Burner May Be Worn Out

Not every burner problem can be corrected with cleaning.

Gas grill burners live in an extremely harsh environment. They are repeatedly exposed to high temperatures, grease, moisture and outdoor conditions.

Over time, burner metal can corrode, split, crack or develop enlarged burner openings.

Once the burner is physically deteriorated, gas may no longer flow through it as designed. This can create uneven flames, poor heat and burners that will not remain lit.

A dirty burner may be cleanable. A burner with major corrosion, holes or splitting generally needs replacement.

5. The Burner May Not Be Positioned Correctly

Gas must enter the burner correctly from the valve and orifice.

If the burner has shifted, was installed incorrectly after cleaning or repair, or is no longer held securely in place, the gas-and-air mixture entering the burner may be affected.

This can sometimes happen after burner replacement or when mounting points inside an older grill have deteriorated.

Because burner alignment involves the fuel-delivery system, a burner that does not appear to be properly positioned should be inspected before the grill is used again.

6. A Grill Valve Could Be Causing the Problem

The gas valves behind your control knobs regulate how much gas is delivered to each burner.

If a valve is damaged, contaminated or worn, the burner may not receive consistent gas flow.

One useful clue is whether the problem affects only one burner.

If three burners operate normally but one repeatedly goes out, the problem may be related to that burner’s components rather than the entire gas supply.

Pro Grill provides professional BBQ grill valve repair and replacement when a valve problem is properly diagnosed.

7. Wind May Be Blowing Out the Burner

Not every flame problem originates inside the grill.

Strong wind can disrupt burner flames, particularly when an outdoor kitchen is located in an exposed area or where surrounding walls funnel wind directly toward the grill.

This can be especially noticeable on elevated properties, coastal homes and open patios.

If your grill works normally on calm days but repeatedly goes out when it is windy, the installation location may be contributing to the problem.

Do not solve this by enclosing the grill or blocking required ventilation. Built-in grills need proper airflow and ventilation for safe operation.

8. Grease and Debris May Be Affecting Airflow

Gas burners require oxygen to maintain proper combustion.

Heavy grease and debris inside a neglected grill can interfere with airflow around burners and other internal components.

The cooking grates may look reasonably clean while the lower portion of the grill contains years of grease, carbon and food debris.

Depending on the grill design, buildup can collect around:

• Burners.
• Briquette trays.
• Heat shields.
• Firebox surfaces.
• Grease-management systems.
• Ventilation openings.

Professional BBQ grill cleaning removes buildup from areas that are often overlooked during routine homeowner cleaning.

At Pro Grill, our deep-cleaning process uses food-safe cleaning products and high-temperature steam to remove grease and buildup while allowing our technicians to inspect visible internal components for deterioration.

9. Several Grill Components May Be Worn at the Same Time

Older grills often have more than one problem.

For example, a grill may have partially clogged burners, deteriorated briquette trays, aging valves and an ignition system that is also beginning to fail.

Replacing one obvious component may improve the grill without fixing every symptom.

That is why professional diagnosis can save money compared with repeatedly replacing parts by guesswork.

If your grill has multiple symptoms — difficulty lighting, weak heat, uneven flames and burners that will not stay lit — consider a professional BBQ grill inspection.