Common Multihead Weigher Problems and Fixes 2026

Common Multihead Weigher Problems and Fixes 2026

Multihead weigher performance is critical for product quality, cost control, and line throughput. In 2026, manufacturers still face recurring issues — inaccurate fills, hopper bridging, vibration, electrical faults and environmental impacts — but modern troubleshooting, preventive maintenance and design tweaks can solve most problems quickly. This article distills field-proven fixes and preventive actions from industry experience and Kenwei's service practice to help packaging engineers, plant managers and maintenance teams restore and sustain optimal multihead weigher performance.

Inaccurate Weights: Causes, Diagnosis and Fixes for multihead weigher Accuracy

Symptom: Final packs are overfilling or underfilling, or recorded mean weights drift beyond target tolerances.

Common causes and how to address them:
- Calibration drift: Re-calibrate using certified calibration masses. Verify calibration across the full weighing range (minimum, mid, maximum). If drift recurs, inspect load cells and junction box for moisture or loose connectors.
- Incorrect combination table or weighting algorithm: Review combination logic and check that the software/firmware version is compatible with the scale model. Run a diagnostics routine to compare expected and measured pan weights.
- Product variability: High variation in product piece weight (e.g., chips, nuts) reduces combination accuracy. Use feeders to pre-dosage, increase the number of heads for better distribution, or use dynamic algorithms that account for variance.
- Mechanical resonance or vibration: Vibrational noise can change pan readings. Isolate the machine base, tighten fasteners, replace worn dampers and verify that the machine is bolted to a flat, level foundation.
- Environmental factors: Drafts, airflow, temperature gradients and humidity can impact accuracy. Shield the weighing area or increase environmental control.
Actionable steps:
1. Immediately run a zero and span calibration with traceable masses.
2. Log weight distributions from each channel; identify the outliers.
3. Temporarily reduce line speed to check if throughput is the root cause.
4. If sensors show inconsistent readings, swap the suspect load cell with a known-good unit to isolate the fault.
Preventive measures: daily weight checks, monthly full calibration records, and routine load-cell inspections.

Feeding and Product Flow Issues: Stop Bridging, Jamming and Uneven Feed

Symptom: Irregular product feed to hoppers, bridging, slow flow or complete blockages.

Common causes and fixes:
- Poor feeder design or settings: Adjust feeder amplitude/frequency. For sticky products, reduce feeder acceleration and increase vibration amplitude on the troughs.
- Product characteristics: Fine powders, flaky or wet products require different chute angles, surface finishes or gas purging. Consider anti-stick coatings or Teflon liners.
- Inadequate hopper agitation: Add agitators or level sensors to keep the product moving.
- Wrong chute geometry: Modify chute angles and widths to meet the product’s angle of repose.
Actionable steps:
1. Observe a slow-motion feed cycle with the machine in diagnostic mode.
2. Mark where product accumulation begins and clear the obstruction.
3. Implement temporary mechanical agitation or manual clearing only if compliant with food safety rules.
Long-term fixes: redesign the feed path with product trials; for high-changeover lines, use modular hoppers and adjustable chutes.

Product-Specific Adjustment Tips for multihead weigher

Soft or fragile products: lower vibration intensity, increase pan depth. Small free-flowing products: reduce pan overlap time and use steeper chutes. Sticky/sugary products: heated or coated feeders help.

Mechanical Wear and Vibration: Bearings, Belts and Pan Problems

Symptom: Increased noise, uneven pan movement, or sudden loss of synchronization across heads.

Causes and actions:
- Worn bearings or shafts cause irregular motion. Inspect bearings for play, discoloration or lubrication failure. Replace per manufacturer intervals.
- Belt/drive wear affects pan timing. Check tension and alignment; replace belts if glazing, fraying or slippage is present.
- Loose fasteners or framework fatigue leads to resonance. Torque-check all critical fasteners and use thread-lock where appropriate.
Maintenance protocol:
- Daily visual checks for abnormal noise or leakage.
- Monthly lubrication and quarterly mechanical inspection.
- Keep a log with parts replaced and vibration analysis if available.

Electronic and Software Faults: PLC, Sensors and Firmware

Symptom: Error codes, inconsistent readouts, loss of control, or unexpected reboots.

Troubleshooting checklist:
- Check for I/O errors: Confirm sensor wiring and examine connectors for corrosion or loose connections.
- Firmware mismatch or bugs: Keep firmware up to date and follow release notes from the OEM. Test firmware updates on one machine offline before fleet deployment.
- Grounding and EMI: Ensure proper grounding and cable routing away from high-voltage lines. Ferrite clamps may reduce interference.
- Memory or storage issues: Clear logs periodically if the HMI or PLC fills up and slows the system.
Actionable steps:
1. Record the fault code and consult the service manual.
2. Attempt a controlled reboot and run self-tests.
3. If persistent, enable diagnostic logging and escalate to service.

Hygiene, Dust and Environmental Control for Reliable multihead weigher Operation

Symptom: Dust accumulation, sticky residues, or hygiene-related faults causing product contamination or mechanical binding.

Key mitigations:
- Establish clean-in-place (CIP) or scheduled manual cleaning compatible with machine IP rating.
- Use food-grade lubricants and ensure washdown compatibility where required.
- Install dust extraction or containment for dusty products.
- Monitor humidity: desiccant cabinets or dehumidifiers can protect electronics and product consistency.
Hygiene best practices:
- Create SOPs for cleaning frequency per product run.
- Use HACCP/ISO 22000 frameworks to define critical control points around the weigher.

Balancing Throughput and Accuracy: Settings, Trials and Acceptance Criteria

Symptom: Either reduced throughput to meet accuracy or high reject rates impacting productivity.

Guidance:
- Run speed/accuracy trials. Start at target weight and incremental speed increases until accuracy falls outside acceptance; determine practical maximum speed.
- Use statistical process control (SPC) on sample weights to set realistic Cpk targets.
- Consider increasing number of heads or pan volume for higher throughput with maintained accuracy.
Example approach:
1. Set baseline speed at 70% rated.
2. Increase in 5% increments and record mean, s.d., and reject rate.
3. Choose a production speed that balances target mean with acceptable reject rate.

Calibration, Verification and Documentation

Good calibration practices reduce repeat troubleshooting:
- Use certified weights and keep calibration certificates up-to-date.
- Define calibration frequency: daily quick-checks, weekly span checks, and quarterly full calibrations or after major maintenance.
- Maintain traceable logs: who calibrated, when, and results.
Regulatory alignment: For food and pharmaceutical packing, follow local regulatory recording practices and ensure validation steps are documented for audits.

Preventive Maintenance Checklist and Recommended Spare Parts

Daily:
- Quick visual inspection, check for jams, check zero balance.
Weekly:
- Clean hoppers and pans, check feeder settings, inspect belts.
Monthly:
- Load-cell check, tighten fasteners, firmware review.
Quarterly:
- Bearing lubrication/replacement schedule, alignment checks, electrical connector inspections.
Suggested spare parts stock (minimum for one production line):
- 2 load cells
- 2 sets of bearings
- 1 spare HMI or PLC module
- Set of belts and drive components
- Selection of fasteners and seals

Quick Troubleshooting Table

Table data derived from industry best practice and Kenwei field service findings.

Kenwei — Manufacturer Profile and How We Solve multihead weigher Challenges

Kenwei is a powerful manufacturer of multi-head weighers. We are committed to the development and manufacturing of metal detectors, multi-head weighers, linear weighers, and check weighers. Our machines are characterized by high speed and high precision. We also provide our customers with one-stop automated weighing and packaging solutions to meet our customers’ customization requirements. Guangdong Kenwei is located in Fusha High-tech Industrial Park, Zhongshan City, Guangdong Province. The company is equipped with an automated weighing and packaging system and has comprehensive capabilities in design and development, manufacturing, marketing, installation and commissioning, technical training, and after-sales service. It has established a good brand image and a reputation for thoughtful and fast service in the packaging machinery industry.
Our vision is to become the world's leading weighing packing machine manufacturer.

Why Kenwei is a strong choice for multihead weigher needs

Brand advantages summarized:
- Proven high-speed, high-precision machines suitable for snack, frozen, confectionery and granular products.
- One-stop solutions: from machine selection and line design to installation, commissioning and training.
- Fast after-sales response and dedicated service teams located close to major manufacturing hubs.
- Customization capability: modular designs for quick product changeover and flexible packaging formats.

Main products and core competencies: Check Weigher, multihead weigher packing machine, multihead weigher, linear weigher, metal detector, packing machine, counting machine, combination weigher, food packaging machine, food packing machinery. Core competitive strengths include high throughput, precision weighing algorithms, modular mechanical design, robust electronic control and integrated packaging line engineering.

Visit Kenwei for product specifications and support: https://www.kenweigroup.com/

FAQs — Common Questions About multihead weigher Problems

Q: How often should I calibrate a multihead weigher?

A: Perform daily quick zero checks, weekly span checks and a full calibration quarterly or after any major maintenance. Increase frequency for critical applications or highly variable products.

Q: My machine shows different weight across heads. How do I fix it?

A: Check for mechanical misalignment, perform a pan balance test, inspect load-cell wiring and connectors, and run diagnostics to isolate the failing channel. Replace faulty load cells or realign pans as needed.

Q: Can multihead weighers handle sticky or oily products?

A: Yes, but they require adapted feeders, coated surfaces or heated chutes and stricter hygiene routines. Trials with sample product are essential to define optimal settings.

Q: What spare parts should we keep on site?

A: Keep critical spares: extra load cells, bearings, belts, key sensors and a spare HMI/PLC module. Stocking these reduces downtime significantly.

Q: How do environmental factors affect weighing accuracy?

A: Air drafts, temperature gradients, humidity and dust can all impact weight readings and mechanical behavior. Control the local environment or install shields and dust extraction to mitigate effects.

Contact and Next Steps

If you need assistance diagnosing a persistent issue or want to upgrade your line for higher throughput and reliability, contact Kenwei’s technical team for consultation, onsite troubleshooting or spare parts quotes. View products and request support at https://www.kenweigroup.com/.

Sources and References

• PMMI — The Association for Packaging and Processing Technologies: industry guides and technical articles on weighing and packaging (2020-2024).
• Packaging World: technical articles and case studies on multihead weigher troubleshooting and maintenance (2018-2024).
• Ishida operator and service manuals: load-cell and combination weigher technical specifications (various models, 2015-2023).
• Food Safety Magazine: articles on hygiene, cleaning procedures and CIP integration for weighing equipment (2017-2022).
• ISO 22000 / HACCP frameworks: best practices for food equipment cleaning and critical control points (2018-2024).
• Kenwei internal service records and field reports (Guangdong Kenwei, 2022-2024).