Middleby Marshall LongWave Infrared Conveyor Oven Preventative Maintenance Checklist
Middleby Marshall crafts high-end ovens that help keep commercial kitchens run effectively. Like all ovens, this unit will require regular preventative maintenance to ensure it’s running efficiently and safely. Use our Middleby Marshall LongWave infrared conveyor oven preventative maintenance checklist to ensure you’re hitting all of the key points you need.
Recommended Cleaning Supplies
- General-purpose cleaner
- Clean towels
- Wire brush
- Vacuum
- Bucket with warm, soapy water
- Nonabrasive cleaning pads
- Soft detailing brush
- Heat-resistant gloves
- Food-safe cleaning products
- Lockout/tagout equipment
- Maintenance inspection form
Safety Precautions Before Cleaning or Maintenance
Before you start disassembling or cleaning a Middleby Marshall LongWave oven, make sure to lock out or tag out the electrical supply. In addition, follow these basic safety rules:
- Complete the oven’s normal shutdown or cooldown procedure.
- Let hot surfaces and removable components cool before handling.
- Disconnect and lock out the electrical supply when the task requires disassembly or service access.
- Use heat-resistant gloves and appropriate personal protective equipment.
- Keep the floor around the oven clean and dry.
- Do not spray water directly into the oven.
- Do not use pressurized steam-cleaning equipment.
- Do not saturate the oven insulation with excessive water.
- Do not use a caustic oven cleaner on the bake chamber.
- Do not use green abrasive scrub pads on LongWave oven components.
Daily Middleby Marshall LongWave Maintenance Checklist
Before Opening
- Inspect the exterior for visible damage.
- Confirm the area around the oven is free of combustible materials.
- Verify that air openings aren’t covered.
- Check the conveyor for visible debris or an obstruction.
- Confirm that the crumb tray and exit tray are correctly installed.
- Inspect the cooling fan filter for heavy grease or dust.
- Confirm that the touchscreen powers on normally.
- Look for active warnings or fault messages.
- Listen for unusual fan, motor or conveyor noises.
- Confirm that the conveyor moves smoothly during startup.
After Each Production Shift
1. Shut Down and Cool the Oven
- Follow the normal control-panel procedure to initiate cooldown.
- When the oven reaches 200°F, the controller returns to the splash screen, the cooling fan shuts off and the conveyor stops.
2. Remove and Clean the Heat Curtain
- Remove the heat curtain.
- Wipe it with a clean towel and general-purpose cleaner.
- Run it through the dishwasher if permitted by your operation.
- Dry it completely.
- Reinstall it correctly.
3. Brush Crumbs From the Conveyor Belt
- Use a wire brush to loosen and remove crumbs from the belt.
- Inspect the belt for food, foil, containers or other obstructions.
- Look for bent, damaged or unusually loose belt sections.
- Verify that the belt tracks smoothly.
4. Clean the Crumb Tray
- Remove the crumb tray.
- Discard loose debris.
- Wipe the tray with a general-purpose cleaner.
- Place it in the dishwasher if permitted.
- Dry it completely.
- Reinstall it in the proper position.
5. Clean the Exit Tray
- Remove the exit tray.
- Wipe it with a clean towel and general-purpose cleaner.
- Run it through the dishwasher if appropriate.
- Dry it thoroughly.
- Reinstall it securely.
6. Remove Loose Debris From the Oven
- Vacuum or sweep loose crumbs from accessible areas inside the oven.
- Do not force tools into heating, sensing or moving components.
- Do not blow debris deeper into the equipment with compressed air.
- Do not use a water hose or steam-cleaning equipment.
7. Clean the Fan Filter
- Remove the filter carefully.
- Rinse it with cold water.
- Allow it to dry completely.
- Inspect it for tears, damage, or excessive grease.
- Reinstall it in the correct orientation.
8. Wipe the Exterior
- Wipe the top, front, and sides with a clean towel and general-purpose cleaner.
- Remove grease from the control-panel area without saturating it.
- Clean around handles, seams and high-touch surfaces.
- Check that labels and warning notices remain legible.
- Dry all surfaces.
Weekly LongWave Oven Maintenance Checklist
1. Deep-Clean the Cooling Fan Filter
- Lift the filter from the bottom of the front panel.
- Wipe it with a clean towel.
- Inspect both sides under good lighting.
- If it is dusty, shake the loose dust from it.
- If it is greasy, wash it in warm, soapy water.
- Rinse it thoroughly.
- Allow it to dry completely.
- Reinstall it correctly.
2. Inspect Conveyor Operation
- Observe the belt through a complete operating cycle.
- Check for jerking, hesitation, slipping or intermittent stops.
- Listen for grinding, scraping or clicking.
- Inspect for food or foreign objects near the conveyor path.
- Confirm the conveyor isn’t rubbing against adjacent components.
- Document changes in belt movement.
3. Review Cooking Performance
- Verify that programmed temperatures and belt times match approved recipes.
- Review recent product-quality complaints.
- Check for uneven browning or incomplete cooking.
- Compare actual cook results with the operation’s standard.
- Make sure employees are selecting the correct preset.
- Confirm that airflow from nearby fans or HVAC vents isn’t disturbing the oven openings.
4. Inspect the Ventilation Area
- Confirm the hood and surrounding ventilation area are operating.
- Check that oven air circulation isn’t blocked.
- Remove stored containers, boxes, towels, or pans from required clearance areas.
- Look for grease accumulation around the hood and oven exterior.
- Report unusual heat, smoke or odors.
Self-Clean Cycle Checklist
Before Starting Self-Clean
- Complete the required manual removal of crumbs and loose debris.
- Confirm that no tools, towels, packaging, pans, or utensils remain in the oven.
- Check that the ventilation system is operating.
- Notify employees that the cleaning cycle is beginning.
- Verify that the surrounding area is clear.
- Follow your model’s touchscreen instructions.
After Self-Clean
- Confirm that the cycle finishes without a fault.
- Remember that the oven doesn’t automatically shut off after self-clean.
- Verify which operating mode the controller returns to.
- Allow the oven to cool if additional manual cleaning is required.
- Document any smoke, odor, fault or unusual operating behavior.
Monthly Preventative Maintenance Checklist
- Review daily and weekly maintenance records.
- Confirm that all employees follow the same cleaning procedure.
- Inspect the conveyor for visible wear or alignment changes.
- Check removable trays and heat curtains for damage.
- Inspect the filter for deterioration.
- Verify that touchscreen presets haven’t been changed without approval.
- Review recurring fault messages.
- Check for longer-than-normal preheat times.
- Compare cooking consistency across shifts.
- Inspect power cords, conduit, disconnects and accessible connections for visible damage without opening electrical compartments.
- Confirm that required model and serial-number information is readable.
- Schedule service for unresolved performance changes.
Six-Month Professional Maintenance Checklist
Ask the service technician to document the following:
- Inspect and tighten electrical control terminal screws.
- Inspect electrical contactor terminals.
- Check the condition and operation of the ventilation system.
- Verify that airflow throughout the oven isn’t blocked.
- Inspect the cooling fan and filter.
- Test conveyor and drive operation.
- Inspect temperature-sensing components.
- Evaluate infrared heating performance.
- Review fault history and operating symptoms.
- Identify worn parts that should be replaced proactively.
- Verify proper reassembly and safe startup.
- Record all findings, adjustments and replacement parts.
Signs Your LongWave Oven Needs Service
Call an authorized service provider if employees observe any of the following:
- Conveyor belt stops or operates intermittently
- Conveyor movement becomes noisy, uneven or jerky
- Oven doesn’t reach its set temperature
- Preheat time becomes noticeably longer
- Actual and programmed temperatures don’t agree
- Product is consistently undercooked or overcooked
- Cooking results vary across the belt
- Touchscreen displays a recurring fault
- Cooling fan doesn’t operate normally
- Filter becomes damaged or can’t be cleaned
- Electrical odor, smoke, arcing or unusual heat is present
- Circuit breaker trips repeatedly
- Self-clean cycle doesn’t complete normally
Simple Preventative Maintenance Log
Make sure to keep a written or digital log for every individual LongWave oven in the space.
Record:
- Date and time
- Oven model and serial number
- Oven position in a stacked configuration
- Cleaning tasks completed
- Filter condition
- Conveyor condition
- Fault codes observed
- Unusual sounds or odors
- Cooking-performance concerns
- Corrective action taken
- Employee initials
- Manager verification
- Service company and work-order number, when applicable
For more troubleshooting or cleaning tips, check out our Middleby Marshall manuals and diagrams.