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A gas grill that will not climb past about 300°F has usually tripped the excess-flow safety device inside the propane tank valve. It engages when burner valves are opened before the tank valve, and it restricts gas to a trickle. Resetting takes a minute: all burners off, tank valve closed, hose disconnected for 30 seconds, reconnected, then open the tank valve slowly before lighting one burner at a time. If the grill still runs cool after that, work down the list — clogged burner ports, spider webs in the venturi tubes, a failing regulator, a nearly empty tank, or grease-blocked heat tents.
How do you do the regulator reset?
- Turn every burner knob to off, including the side burner.
- Close the tank valve fully.
- Disconnect the regulator coupling from the tank and wait at least 30 seconds.
- Reconnect and hand-tighten — no wrench.
- Open the tank valve slowly, a quarter turn at a time, and pause 10 seconds.
- Light the first burner, then add the others one at a time.
The critical habit is the order: tank valve first, burners second, always. Snapping the tank valve wide open with a burner already turned on is exactly what the safety device is designed to catch, and it is why the same grill trips repeatedly for some owners and never for others.
What else causes a cool grill?
| Cause | Symptom | Fix |
|---|---|---|
| Tripped flow limiter | All burners low, caps near 300°F | 60-second reset above |
| Spider webs in venturi tubes | Yellow flame, whooshing, flame at the valve | Brush the tubes out; do it every spring |
| Clogged burner ports | Flame on part of the burner only | Cool burner, clear ports with a wire or pin |
| Corroded burner tubes | Flame escaping from holes, uneven heat | Replace the burner set |
| Failing regulator | Low flame after reset, humming | Replace regulator and hose assembly |
| Nearly empty tank | Fades over the cook, worse in cold | Weigh the tank; keep a spare |
| Grease-loaded heat tents | Heat is uneven, smoky, flares | Deep clean the cookbox |
How do you tell if the burners are the problem?
Light the grill in daylight and look along each burner tube. A healthy flame is mostly blue with small yellow tips, even along the full length of the tube, and roughly the same height on every burner. Gaps of no flame mean blocked ports. A tall lazy yellow flame across the whole burner means a gas or air supply problem upstream — venturi or regulator. Flame escaping in the wrong place means the tube has rusted through and needs replacing, which is a straightforward job covered in how to replace gas grill burners. Burners are consumable parts, typically lasting 5 to 8 years, and burner failure is a normal part of the arc described in how long a gas grill lasts.
Is it just running low on propane?
Check by weight, not by the inline gauge — gauges read pressure, which stays near constant until the tank is nearly dry. Every cylinder is stamped with a tare weight marked TW, usually around 17 pounds; put the tank on a bathroom scale and subtract it, and the remainder is pounds of propane left. In cold weather a tank below about a quarter full often cannot vaporize fast enough to feed every burner. The quick field methods are in telling if a propane tank is empty without a gauge, and expected run times in how long a propane tank lasts.
When should you stop and call a professional?
If soapy water bubbles anywhere along the hose, at the regulator coupling or at the tank valve, you have a leak — close the valve and replace the failing part before using the grill again. Do not attempt repairs to a hard-plumbed natural gas line, a manifold or a gas valve body; that work belongs to a licensed gas fitter, and local codes govern it. Never search for a leak with a flame, and never operate a grill with a persistent gas smell. Everything else on this page is homeowner-level maintenance, most of which falls out of a proper seasonal clean — see how to clean a gas grill.
We do not buy, test or physically handle any product on this site — troubleshooting here reflects manufacturer service documentation, CPSC safety guidance and aggregated owner reports. See how we rank, or browse our best gas grill picks.
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