Bull BBQ · Troubleshooting
Troubleshooting Uneven Heat on a Bull BBQ Grill
Uneven heat on a Bull almost always traces to one of three things: dirty burner tubes, undersized gas line, or carbon-crusted flame tamers. Fifteen minutes with a flashlight + a pipe cleaner solves most cases.
By Reed · Updated November 8, 2026
What you need
- Flashlight or phone light
- Pipe cleaner or thin venturi brush
- Shop vacuum
- Multimeter (optional, for regulator diagnosis)
Step by step
Light each burner individually and visually compare
Turn OFF all burners, then light them one at a time on high. Compare the flame pattern — the weak burner stands out immediately. Blue flame with minor yellow tips = good. Yellow flame = restricted gas. Low flame + hissing = restricted venturi.
Pull the suspect burner tube + clean the venturi
With the grill cold, pull the grates + flame tamers + the suspect burner tube. Look into the venturi (the bell-shaped opening at the valve end). Insect nests (especially spider webs) are the #1 cause of weak-burner complaints on stored grills. Run a pipe cleaner through, then blow out with compressed air.
Check the flame tamers for carbon buildup
Carbon-crusted flame tamers drop onto the burner tubes and choke gas flow. Pull them, scrub with a plastic scraper, wash with hot soapy water, dry completely. Reinstall carefully so they sit flat.
If still uneven: verify gas line sizing
Undersized gas lines starve the burners furthest from the manifold. Angus wants 3/8-inch LP minimum; Brahma wants 1/2-inch NG. If the line is smaller than spec, no amount of cleaning will fix the weak outer burners.
Last resort: regulator test with soapy water
At this point, test the regulator by replacing it with a known-good spare. Bull regulators rarely fail but when they do, the symptom is consistent across all burners (not just one). Replace with Bull's OEM part only — aftermarket regulators can over- or under-flow.
Common mistakes
- Replacing parts in the wrong order. Order matters: venturi → flame tamers → gas line sizing → regulator. Jumping to the regulator first wastes money.
- Cleaning the venturis with wire. Steel wire can leave shards that catch fire. Use a pipe cleaner or nylon venturi brush only.
- Overlooking flame-tamer alignment. A slightly-off flame tamer deflects heat to one side. After cleaning, ensure every tamer sits level and centered over its burner.
Hands-on tips
- Clean venturis annually, even if the grill seems fine. Stored outdoors = spider-web magnet.
- Keep a pipe cleaner + flashlight in the grill cart or outdoor kitchen cabinet. It's a 60-second check.
- If you hear a slight 'poof' or whoosh when igniting, that's usually a venturi partial-block, not a dangerous condition. Clean and re-test.
Questions people ask
Can I just run the weak burner on low to compensate?
No — the imbalance will burn food unevenly. Fix the root cause. Cleaning a venturi takes 10 minutes and solves most cases.
What if only the rear IR burner is weak?
IR burners use a ceramic-matrix that clogs with grease differently than tube burners. See our /guides/bull-bbq/maintenance-infrared-burner page for the IR-specific procedure.
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