A commercial coffee roaster is a significant investment — and like any precision machine, it needs regular maintenance to perform at its best. This guide covers the complete maintenance schedule for gas drum coffee roasters, including daily checks, weekly cleaning, monthly servicing, and annual overhaul tasks.
Why Maintenance Matters
Neglecting roaster maintenance leads to:
- Inconsistent roast profiles — temperature drift causes batch-to-batch variation
- Increased fire risk — chaff buildup in the exhaust system is a leading cause of roastery fires
- Component failure — bearing wear, seal degradation, burner fouling
- Higher energy consumption — a dirty heat exchanger can increase gas use by 15 to 25 percent
- Voided warranty — most manufacturers require documented maintenance records
Daily Maintenance (Every Roasting Session)
- Empty and clean the chaff collector before each session
- Check the drum for coffee residue and wipe clean with dry cloth if needed
- Inspect the gas burner flame — should be blue, even, and stable
- Check the temperature probe readings against a reference thermometer monthly
- Listen for unusual sounds from drum bearings or the motor
- Inspect the cooling tray and agitator arm for buildup
Weekly Maintenance
- Deep-clean the chaff collector and exhaust ducting — remove all chaff accumulation
- Clean the drum interior with a stiff brush (dry — no water inside the drum)
- Inspect the door seal (gasket) for wear or cracking
- Check all electrical connections at the control panel for signs of heat or corrosion
- Clean the cooling tray screen and verify the cooling fan runs at full speed
- Lubricate drum shaft bearings with food-grade grease (check manufacturer spec)
Monthly Maintenance
- Inspect the burner ports — clean with a soft brush if any ports show deposits
- Check and calibrate thermocouples — compare readings to a calibrated reference probe
- Inspect the afterburner (if equipped) — check temperature and clean combustion chamber
- Test all safety cutoffs and emergency stop functions
- Check belt tension on the drum drive — adjust if slack
- Inspect smoke filtration system (electrostatic or afterburner)
- Review Artisan or PLC roast logs for temperature drift trends
Annual Overhaul
- Full bearing replacement (drum and motor bearings)
- Burner service — replace burner nozzle and ignition electrode
- Complete thermocouple calibration and replacement if drift exceeds spec
- Inspect drum for wear and measure drum wall thickness
- Full electrical inspection — insulation resistance test, earth continuity check
- Replace door gasket if any signs of heat loss
- PLC firmware update (on Siemens PLC models — check Yoshan support for latest version)
- Full cleaning and re-seasoning of the drum interior
Maintenance for Siemens PLC Models (YS Series)
Yoshan’s YS Series uses a Siemens S7-200 SMART PLC with touch HMI. Additional maintenance tasks for PLC-controlled roasters include:
- Back up roast profiles and PLC parameters to USB drive monthly
- Check HMI touch screen for dead zones — calibrate if needed
- Inspect PLC cabinet for dust ingress — clean with compressed air quarterly
- Verify all sensor inputs match expected values at startup
Spare Parts to Keep on Hand
To minimize downtime, keep these common wear parts in stock:
- 2 to 4 spare thermocouples (K-type, matching your model spec)
- Spare drum door gasket
- Spare burner ignition electrode
- Drive belt (if belt-driven drum)
- Fuse set for the control panel
Yoshan supplies spare parts for all models, including those over 10 years old. Contact our after-sales team for a spare parts list specific to your machine.
When to Call for Technical Support
Contact Yoshan’s 24-hour support team if you experience:
- Temperature readings that deviate more than 2 degrees C from set point
- Burner fails to ignite or goes out during roasting
- Unusual vibration or noise from the drum
- PLC alarm codes that do not clear after restart
- Smoke from the drum area (not the exhaust) during roasting
Need spare parts or technical support? Contact our after-sales team — we respond within 24 hours and provide remote diagnostics via WhatsApp video call.
