Quick Answer
Common causes include blocked burner ports, an insect nest in that burner's venturi tube, a burner tube that has slipped off its valve orifice, a blocked orifice, and no spark reaching that position. Check first that the tube is correctly seated over the orifice — reassembly after cleaning is a frequent cause of one dead zone.
Which symptom matches yours?
- Three burners light and one does nothing
- The dead burner lights only partway along the tube
- The zone lights but is much weaker than the others
- Flames on that tube are yellow and sooty
- The problem appeared after cleaning or moving the griddle
- The igniter sparks at the other positions but not that one
Diagnostic decision tree
No flame at all on one tube, spark present
→Gas is not reaching that burner — orifice, venturi or seating.
No spark at that position, others spark
→Electrode position, wiring or ground at that burner.
Flame on only part of the tube
→Blocked ports along the affected section.
Yellow sooty flame
→Restricted venturi or an air-shutter/mixture problem.
Started right after cleaning
→The burner tube is not seated over the valve orifice.
Fixes, easiest first
1. Confirm the burner tube is seated on its orifice
AddressesReassembly error, the most common cause of one dead zone after maintenance.
- Shut off the gas at the cylinder and let the griddle cool completely.
- Lift the cooktop off and look at the valve end of the dead burner tube.
- The valve orifice should sit centred inside the venturi opening, not off to one side or outside it.
- Reseat the tube and secure any retaining screw or clip so it cannot shift.
Expected resultThat zone lights normally on the next attempt.
When to stopIf reseating fixes it, nothing else is required.
The cooktop is heavy — lift it cold and with help.
2. Clear the burner ports
AddressesGrease, carbon or corrosion blocking part or all of the tube.
- With the tube cool and removed or exposed, inspect the port row with a flashlight.
- Work a stiff wire or opened paperclip through each blocked port, pulling debris outward.
- Brush the tube with a stainless brush and knock out loose debris.
- Refit and test with the other burners off, so you can see that zone clearly.
Expected resultAn unbroken row of small blue flames along the full tube length.
When to stopReplace the burner if the ports have corroded together or the tube is split.
3. Clear the venturi tube
AddressesInsect nesting, a documented cause of single-burner failures on outdoor propane appliances.
- Remove the burner tube from the frame.
- Shine a light through the venturi end; spider webbing shows as grey fibrous material.
- Push a venturi brush or a long pipe cleaner through the tube from the burner end and pull the debris out.
- Reinstall the tube over the orifice and confirm seating.
Expected resultBlue flames instead of yellow, and immediate lighting.
When to stopPersistent yellow flame after clearing suggests an orifice or mixture issue.
4. Check the valve orifice
AddressesA blocked or damaged brass orifice starving that burner.
- With the gas off, inspect the small brass orifice at the valve end for grease, paint overspray or debris.
- Clear it with a soft brush or compressed air only — never drill or enlarge an orifice.
- If the orifice appears damaged, order the correct replacement part for your Blackstone model.
Expected resultFlame equal to the neighbouring burners at the same setting.
When to stopNever modify an orifice; a wrong-size opening is a fire hazard.
Do not drill, ream or file a gas orifice under any circumstances.
5. Check spark at that position
AddressesAn ignition fault confined to one zone.
- With the cylinder valve closed, press the igniter in dim light and look for a spark at that burner's electrode.
- Clean the electrode tip and its ceramic insulator with isopropyl alcohol and dry thoroughly.
- Confirm the electrode wire is seated and the ceramic is not cracked.
- Until the spark is restored, light that burner with a long lighter at the burner tube, with the cooktop lifted or through the front access as the manual describes.
Expected resultA visible spark and immediate ignition.
When to stopCracked ceramic or an eroded electrode means part replacement.
If a burner does not light within about five seconds, turn the knob off and wait five minutes before trying again so unburned gas disperses.
Blackstone 36" Griddle: what makes this model different
- Burner layout
- Four independent burner tubes, each with its own control valve and orifice — a single dead zone isolates to that assembly
- Ignition
- Battery-powered spark igniter with electrodes at the burner positions
- Access
- The rolled steel cooktop lifts off the frame for burner access; it is heavy and should be handled cold
- Frequent fault
- Burner tube not reseated over the valve orifice after cleaning or transport
- Service parts
- Burner tubes, electrodes and wiring, control valves, orifices
When to stop troubleshooting
- Persistent gas smell around the affected burner — close the cylinder valve and stop.
- Flame burning back inside the burner tube with a whistling or roaring sound.
- A cracked, melted or hardened hose, or a damaged regulator.
- Any flame outside the burner area, under the frame, or around a valve stem.
- The zone still will not light after reseating, clearing the ports and venturi, and confirming spark — contact Blackstone support for valve or manifold service.
Sources and references
- Blackstone customer support — griddle troubleshooting and warranty parts — Blackstone Products
- Blackstone griddle owner's manuals — Blackstone Products
- Propane safety: cylinders, regulators and leak checks — Propane Education & Research Council
Procedures are summarised from the sources above and from the owner's manual for this model. Always follow the manual supplied with your grill where it differs.