TL;DR
Burner lockout is most often a failed UV flame sensor or fuel supply pressure drop. Check fuel pressure first, then test the flame sensor output with a multimeter.
What you might see
- burner lockout fault on the controller display
- oven failing to reach setpoint repeatedly
- flame-fail alarm activating at ignition or during run
- no ignition spark audible
Likely causes
UV flame sensor degraded, providing a weak signal to the burner safety control
Fuel supply pressure low or fluctuating, preventing stable combustion
Igniter electrode fouled with carbon or positioned too far from the fuel nozzle
Combustion air proving switch tripped due to blocked intake or failed blower
Required tools
- Multimeter (voltage and continuity settings)
- Gas pressure test gauge or manometer
- Clean dry cloth
- Replacement UV flame sensor (if needed)
- Replacement igniter electrode (if needed)
- LOTO kit
Safety first
- Never bypass or jumper burner safety interlocks, flame sensing, or gas valve proving circuits.
- Close the manual gas shutoff valve before opening burner access panels.
- After any repair to the burner system, perform a full light-off test and observe stable flame before leaving the oven unattended.
Procedure
- 1
Read the burner controller fault code on the Despatch PCC controller display. Note the exact fault code for the diagnostic log.[1]
- 2
De-energize the oven and lock out the main disconnect.
Warning: The burner system uses fuel gas. Never bypass or jumper safety interlocks. Verify the gas supply valve is closed before opening burner access panels. - 3
Verify fuel supply pressure at the inlet of the gas train with an inline pressure gauge or test port. Compare to the Despatch PCC specification for this model.[1]
- 4
If pressure is correct, inspect the UV flame sensor. Remove the sensor and wipe the sight glass end clean with a dry cloth. Reinstall and attempt a burner light-off.
- 5
If the sensor still fails to confirm flame, test the sensor output voltage per the burner manufacturer's spec. A healthy UV sensor produces a defined DC signal when exposed to a UV source (a lighter flame works for bench test).
- 6
Inspect the igniter electrode tip. Replace the electrode if the tip is eroded, cracked, or coated with carbon deposits.[1]
- 7
Check the combustion air proving switch. With the blower running, verify the switch is closed with a multimeter. A stuck-open switch prevents light-off.
- 8
After any repair, perform a manual light-off test and confirm the burner holds flame for the full combustion period before returning the oven to automatic operation.
Sources
Despatch PCC Industrial Cabinet Oven Operation and Maintenance Manual, Despatch (ITW EAE)
Despatch PCC Industrial Oven Instruction Manual, burner troubleshooting and fault code guide (general)
View source
More guides for Despatch (ITW EAE) PCC
How to clear a stuck conveyor or charge inside a Despatch PCC industrial oven
A stuck conveyor inside the oven is a fire and product-damage risk. Turn off the heat immediately, do not open the door until below 50 C, then diagnose the drive or roller failure.
How to reduce high fuel consumption on a Despatch PCC industrial oven
High fuel consumption almost always means heat is escaping: damaged refractory, failed door seals, or excess air in the combustion mix. Inspect the refractory and door gaskets first.
How to fix long heat-up time on a Despatch PCC industrial oven
Slow heat-up is usually one or more degraded heating elements or a failed power contactor on a zone. Measure element resistance to find the weak zone.
How to assess and repair refractory cracks in a Despatch PCC industrial oven
Refractory cracks are caused by thermal cycling fatigue. Hairline surface cracks can be sealed with refractory cement; through-cracks or spalled panels need full panel replacement.
Stop fixing the same fault twice.
Dovient turns guides like this into your team's shared playbook, with AI that catches recurring issues before they break the line.