Troubleshooting / Reactor

Reactor Troubleshooting

The most common reactor problems on the plant floor, with the likely causes and the fix for each. Part of the OEE Lab troubleshooting directory.

Not your exact symptom?

Describe it in the symptom finder and search the whole directory.

Open the symptom finder

Problems on this page:

Temperature control problemsAgitator or seal issuesPressure or relief concernsBatch to batch variationFouling on the wallsCharging or weighing errorsJacket leaking into the productGlass lining damageAgitator not starting or trippingTemperature probe faults

Temperature control problems

Hits OEE: Quality

Symptoms: Cannot hold/reach temperature, exotherm overshoot, off-spec batch.

Jacket/coil fouling or flow
Clean the jacket/coil; check heating/cooling flow.
Control loop tuning
Tune the temperature loop; check the control valve.
Agitation poor (hot/cold spots)
Verify agitation; check the impeller and baffles.

Prevention: Heat-transfer surface upkeep, loop tuning, agitation checks.

Agitator or seal issues

Hits OEE: Availability

Symptoms: Mechanical-seal leak, agitator vibration, contamination risk.

Mechanical seal wear
Service the seal; check the seal flush/barrier fluid.
Bearing or coupling wear
Inspect drive bearings and coupling.
Imbalance or fouling on the impeller
Clean and inspect the impeller and shaft.

Prevention: Seal-support upkeep, drive condition monitoring, impeller checks.

Pressure or relief concerns

Hits OEE: Availability

Symptoms: Pressure alarms, relief device lifts, batch holds for safety.

Vent/relief path blocked
Verify clear vent/relief paths; inspect rupture disc/PRV.
Overcharge or reaction upset
Follow charging/recipe controls; manage the reaction rate.
Instrument or interlock fault
Check pressure transmitters and safety interlocks.

Prevention: Relief-path integrity, recipe control, instrument/interlock testing.

Batch to batch variation

Hits OEE: Quality

Symptoms: Yield or quality differs from batch to batch with the same recipe.

Raw material variation
Check the raw material lots against their specifications.
Charging inaccurate
Calibrate load cells and flow meters.
Temperature profile differs
Compare the batch temperature profiles.
Agitation differs
Check agitator speed and power.

Prevention: Batch records compared for every deviation.

Fouling on the walls

Hits OEE: Availability

Symptoms: Build-up on the walls reduces heat transfer and lengthens batches.

Wall running too hot
Check the jacket temperature.
Poor agitation near the wall
Check the agitator and baffles.
Product prone to sticking
Clean between batches.

Prevention: Heat transfer trended per batch.

Charging or weighing errors

Hits OEE: Quality

Symptoms: The wrong amount of a material is charged.

Load cell drift
Calibrate the load cells.
Flow meter error
Check the meter.
Manual additions
Use a second-person check and sign-off.

Prevention: Calibration on schedule.

Jacket leaking into the product

Hits OEE: Quality

Symptoms: Heating fluid or water found in the product.

Jacket corrosion
Inspect and repair the jacket.
Weld cracks
Pressure test the jacket.
Thermal stress
Check heating and cooling rates.

Prevention: Jacket tests at shutdowns.

Glass lining damage

Hits OEE: Availability

Symptoms: Chips, cracks or holes in a glass-lined vessel.

Thermal shock
Follow the vessel maker's temperature difference limits.
Mechanical impact
Protect the lining from tools and dropped parts.
Chemical attack
Check the process chemistry against the lining limits.

Prevention: Spark tests on a schedule.

Agitator not starting or tripping

Hits OEE: Availability

Symptoms: The agitator will not start, or trips soon after starting.

Viscous or settled batch at start
Start the agitator before solids settle or follow the restart procedure.
Motor or drive fault
Check the drive alarms.
Gearbox fault
Check the gearbox oil and noise.
Mechanical seal support system alarm
Check the seal pot or support system.

Prevention: Restart procedure written for settled batches.

Temperature probe faults

Hits OEE: Quality

Symptoms: The batch temperature reading drifts, jumps or fails.

Fouled thermowell
Clean the thermowell.
Failed probe
Replace the probe.
Wiring fault
Check the wiring and connectors.

Prevention: Probe checks against a reference on schedule.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: granulator · grinding mill · crusher · filter press · distillation column

Stop the same fault coming back

Recurring reactor 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
The directory stays free.

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