Normal vs. a problem
Some unevenness is built in. The back of the grill runs hotter than the front because heat rises toward the hood. The sides near the walls can lag a bit. A grill with a rear infrared rotisserie burner or a sear zone will obviously have a hot spot by design.
What we mean by a problem: a whole burner zone noticeably cooler than its neighbors on the same setting, cold patches in the middle of a burner, flames that are tall on one end and barely there on the other, or food that cooks unevenly in a pattern that matches one burner. Those point to parts that can be cleaned, adjusted or replaced.
What causes it, most common first
Clogged burner ports
Grease and carbon close off ports along part of the burner. That section burns low or not at all.
Learn moreSpiders or debris in a venturi
A partial blockage at the burner inlet starves one burner of gas and air. It lights, but runs small and often yellow.
Learn moreRusted-out burner sections
Ports corrode wider in one spot, creating a tall flame there and a weak one everywhere else.
Warped or clogged heat plates
Heat plates and briquette trays spread heat. When they warp, crack or fill with grease, heat channels straight up in some spots and is blocked in others.
Learn morePartially clogged orifice
The small brass fitting that meters gas into the burner can get blocked by debris, cutting flow to one burner.
Low gas pressure overall
A tripped propane regulator or undersized gas line can make the whole grill weak, and the ends lag most.
Learn moreHomeowner checks
Grill off and cool, gas supply closed unless a step says otherwise.
- Clean the grates and do a bread test: lay slices of white bread across the grill on medium for a minute and look at the toast pattern.
- Lift the grates and heat plates. Look for grease pooled on plates or a plate that has sagged or cracked.
- Light the burners with the plates out and look at the flames. Each burner should have an even row of blue flames along its length.
- If one burner is weak, turn it off, let it cool, pull it, and shine a flashlight into the venturi for webs.
- On propane, reset the regulator if every burner seems weak.
- Clean ports gently with a soft brass brush, brushing along the length, not into the holes.
What to leave to us
If the cause turns out to be a clogged orifice, a valve that won't open fully, or a burner that won't seat properly, that's where we'd take over. Orifices and valves are part of the gas train, and a misthreaded orifice leaks right next to an open flame. Anything that smells like gas should go straight to our gas smell page before you light it again.
How we fix uneven heat
- 1
Map it
We look at flame pattern on each burner with the plates out, and check supply pressure, before pulling anything apart.
- 2
Deep clean the cooking system
Burners, heat plates, grates and firebox get cleaned. A lot of uneven heat is just years of grease in the wrong places.
- 3
Clear the gas path
Venturi tubes cleared, orifices inspected and cleaned or replaced.
- 4
Replace damaged parts
Burners with rusted-out ports and heat plates that have warped or burned through get replaced with matched parts.
- 5
Test across the grate
We relight, check every burner on high and low, and confirm the heat is even before we leave.
Uneven heat questions
Will a deep cleaning fix my hot spots?
Often, yes. Grease-clogged ports and heat plates cause a large share of uneven heat. If parts are physically damaged, cleaning helps but won't fully fix it.
Why is the back of my grill always hotter?
That's normal on most grills. Heat rolls toward the back under the hood. Use the front as your cooler zone.
Could it be my gas supply?
If every burner is weak, possibly. If it's one burner or one area, the cause is almost always at that burner.
Do I need new heat plates?
If they're cracked, burned through, or warped so they don't sit flat, yes. If they're just dirty, cleaning is enough.
How much does it cost to fix?
It depends on whether it needs cleaning, parts, or both, and on the brand. Send a photo of your bread test and the burners and we'll quote it.
Related guides
BBQ Grill Repair
On-site repair for gas grills: ignition, burners, valves, regulators, gas leaks and the hardware that wears out, with common parts carried on the truck.
TroubleshootingSigns Your Burners Need Replacing
How to tell a dirty burner from a worn-out one, with flame patterns to watch for and a safe way to pull and inspect them.
TroubleshootingWhy Your Grill Won't Get Hot
The common reasons a gas grill runs cold, in the order techs check them, including the regulator reset that fixes many propane grills.
TroubleshootingSpiders in Burner Tubes
Spider webs in burner venturi tubes are a common cause of weak flames and flashback fires. Here's how to spot it, clean it and prevent it.
Care & how-toBasic Cleaning vs. Deep Cleaning
The difference between a routine grill cleaning and a full teardown, with step-by-step instructions for both.
Tired of cooking around a cold spot?
Call or text us, or send a few photos. We'll tell you whether it needs a cleaning, parts, or both.