Problems on this page:
Burner will not light or keeps tripping
Hits OEE: Availability
Symptoms: The oxidiser fails to start, or the burner trips during the purge, ignition or run.
Flame scanner dirty or failing
Clean the scanner lens and check its signal; the burner management system must never be bypassed.
Gas pressure outside the switch limits
Check the gas train pressure and the high and low pressure switches.
Combustion air fan or damper fault
Check the fan, its airflow switch and the damper positions.
Purge not completing
Check the airflow and the damper limit switches that prove the purge.
Prevention: Burner start attempts and trip causes recorded so repeat faults stand out.
Combustion chamber temperature too low
Hits OEE: Quality
Symptoms: The chamber does not hold the temperature set in the permit or the process design.
Burner output limited
Check the burner firing rate, the gas valve and the control loop.
Process air flow higher than the design
Check how many extraction points are open and the fan speed.
Heat recovery bypass stuck
Check the bypass damper and its actuator.
Temperature sensor fault
Compare the thermocouple with a second reading and replace it if it drifts.
Prevention: Chamber temperature trended against the permit limit.
Emissions above the permit limit
Hits OEE: Quality
Symptoms: Stack monitoring shows emissions above the permitted level.
Chamber temperature or residence time too low
Check the temperature and the air flow against the design values.
Poisoning or fouling of the media or catalyst
Inspect the ceramic media or catalyst and clean or replace it.
Valve leaking between inlet and outlet on regenerative units
Check the poppet or rotary valve seals for leaks.
Monitoring instrument drift
Check the analyser calibration.
Prevention: Emissions results reviewed against the permit on the schedule it sets.
Pressure drop across the bed rising
Hits OEE: Performance
Symptoms: The fan has to work harder, and extraction from the process falls as the pressure drop climbs.
Ceramic media fouled with particulate or condensed material
Run a bake-out or clean the media as the maker specifies.
Inlet filter blocked
Change or clean the inlet filter and check its differential pressure gauge.
Media damaged or collapsed in a bed
Inspect the beds at the next planned stop and replace damaged media.
Damper not opening fully
Check the damper positions against their indicators.
Prevention: Pressure drop trended per bed so fouling shows early.
Switching valves faulting
Hits OEE: Availability
Symptoms: A regenerative oxidiser stops with a valve position or timing fault.
Actuator air pressure low
Check the air supply, the regulator and the actuators for leaks.
Limit switches out of adjustment
Adjust or replace the limit switches so they prove the valve position.
Valve seats worn or fouled
Inspect the seats at a planned stop and clean or replace them.
Hydraulic unit fault on hydraulically driven valves
Check the oil level, the filter and the pump pressure.
Prevention: Valve cycle counts and faults recorded per valve.
High solvent load alarm
Hits OEE: Availability
Symptoms: The oxidiser trips or opens its bypass on a high concentration alarm.
Process releasing more solvent than the design
Check the process for spills, open containers or a change in the product being run.
Dilution air damper not opening
Check the dilution damper, its actuator and its control signal.
LEL analyser reading high
Check the analyser with calibration gas.
Extraction from part of the process blocked
Check the ducting and branch dampers so the load is not concentrated.
Prevention: Solvent concentration trended against the alarm limit.
Gas consumption too high
Hits OEE: Performance
Symptoms: The oxidiser burns more gas than it used to for the same production.
Heat recovery efficiency down
Check the media, valves and heat exchanger for fouling or leaks.
Running at full temperature when the process is idle
Use the idle or standby mode during breaks.
Too much air drawn through the oxidiser
Close extraction points that are not in use.
Burner tuning drifted
Have the burner combustion tuned.
Prevention: Gas use per production hour recorded weekly.
Fan vibration or noise
Hits OEE: Availability
Symptoms: The main process fan vibrates or gets noisy.
Build-up on the fan impeller
Clean the impeller with the fan isolated and locked off, and look for the source of the build-up.
Fan bearings worn
Check bearing temperature and vibration and plan the replacement.
Belt or coupling worn
Check the belts or the coupling and their alignment.
Mounting bolts or base loose
Tighten the bolts and check the base and anti-vibration mounts.
Prevention: Fan vibration checked on a route.
Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.
Related equipment guides: fan / blower · heat exchanger · paint booth · dust collector · control valve · coffee roaster
Stop the same fault coming back
Recurring thermal oxidiser stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.
Book a Fabrico demo
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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary
Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover