Problems on this page:
Weak vacuum, packs not tight
Hits OEE: Quality
Symptoms: Packs come out loose or with air pockets, or the vacuum gauge does not reach its usual value.
Vacuum pump oil low or degraded
Check the oil level and colour and change the oil as the maker specifies.
Lid or chamber seal worn or damaged
Inspect the lid gasket for cuts and flattening and replace it if damaged.
Vacuum time or level set too low
Check the programme for the product and restore the validated setting.
Leaking valve or hose
Check hoses and valves for leaks with the machine running.
Prevention: Vacuum level checked at the start of every shift.
Seals not holding (leakers)
Hits OEE: Quality
Symptoms: Packs lose vacuum after hours or days, or leak tests fail at the seal.
Seal time or temperature wrong for the film
Set seal time and temperature for the film in use and confirm with a seal test.
Product or liquid on the seal area
Keep the seal area clean when loading, and use bag collars for messy products.
Worn seal bar cover or counter strip
Replace the seal bar cover tape and the silicone counter strip on schedule.
Film or bag not suited to the machine
Check the bag specification with the supplier for this machine and product.
Prevention: Seal test on packs from each shift and each programme.
Seal burnt through
Hits OEE: Quality
Symptoms: The seal is brittle, holed or cut through, or the bag melts at the seal line.
Seal time too long or temperature too high
Reduce seal time step by step until the seal passes the test without burning.
Seal bar cover tape worn through
Replace the cover tape.
Thinner bags than the setting was made for
Use a separate programme for each bag thickness.
Seal pressure too high
Check the seal pressure setting and the bellows or cylinders.
Prevention: One programme per bag type, with the seal settings recorded.
Wrinkled seals
Hits OEE: Quality
Symptoms: Seals show folds and creases that can leak.
Bag placed unevenly across the seal bar
Lay the bag flat and straight across the seal bar.
Bag too large for the product
Use a bag size that fits the product without large overhang.
Seal pressure uneven along the bar
Check the counter strip and the seal bar for even contact.
Product too close to the seal line
Leave the gap the maker recommends between product and seal.
Prevention: Bag sizes listed per product at the machine.
Cycle time too slow
Hits OEE: Performance
Symptoms: Each cycle takes longer than it used to, and output falls.
Vacuum pump worn or oil contaminated
Change the pump oil and have the pump checked if pumping speed stays low.
Exhaust or inlet filters blocked
Clean or replace the filters.
Gas flush or vacuum time set longer than needed
Review the programme times against the validated settings.
Filler plates not used for small products
Use the chamber filler plates so there is less air to remove.
Prevention: Cycle time per programme recorded and checked weekly.
Lid not closing or opening properly
Hits OEE: Availability
Symptoms: The lid will not stay down, opens slowly or the cycle does not start.
Gas springs or hinges worn
Replace worn gas springs and check the hinges.
Lid sensor or switch misaligned
Check and adjust the lid sensor that starts the cycle.
Vacuum release valve blocked
Clean the release valve so the chamber vents fully at the end of the cycle.
Debris on the lid gasket
Clean the gasket and the chamber rim.
Prevention: Lid gasket and hinges checked during the daily clean.
Gas flush not reaching the set level
Hits OEE: Quality
Symptoms: Residual oxygen in gas flushed packs is above the specification.
Gas supply pressure low
Check the gas bottle or supply pressure and the regulator.
Gas nozzle blocked or misplaced
Clean the nozzles and check their position in the bag.
Vacuum before flushing too short
Check the vacuum stage of the programme so air is removed before the gas goes in.
Leak between flush and seal
Check the chamber seal and the timing between flush and seal.
Prevention: Residual oxygen measured on sample packs each shift.
Vacuum pump running hot or smoking
Hits OEE: Availability
Symptoms: The pump is too hot to touch, an oil mist comes from the exhaust or the pump trips.
Oil level low or oil past its life
Top up or change the oil with the grade the maker specifies.
Exhaust filter clogged
Replace the exhaust filter, which also stops the oil mist.
Pump working beyond its duty
Check whether the cycle rate is higher than the pump was sized for.
Hot room or poor airflow around the pump
Give the pump space and cool air around it.
Prevention: Pump oil and exhaust filter on the planned maintenance list by run hours.
Liquid drawn into the pump
Hits OEE: Availability
Symptoms: Liquid or product juice appears in the pump oil, and the vacuum falls off.
Wet products boiling under vacuum
Chill the product before packing and stop the vacuum earlier for wet products.
Vacuum level set too deep for liquids
Use a programme with a lower final vacuum or sensor control for liquid products.
No liquid trap fitted
Fit a liquid separator between the chamber and the pump where the maker offers one.
Oil not changed after contamination
Change the oil at once after liquid gets in, and run the pump to dry it as the maker describes.
Prevention: Oil checked for water or product after packing wet products.
Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.
Related equipment guides: tray sealer · vacuum pump · form-fill-seal machine · flow wrapper · checkweigher · pouch filling machine · impulse heat sealer
Stop the same fault coming back
Recurring vacuum packaging machine 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