Troubleshooting BOH Equipment

Calibrating a BUNN tea brewer (such as the ITCB or Infusion Series) ensures that the machine actually dispenses the volume it thinks it is dispensing. This process involves measuring the "Flow Rate" (ounces per minute) for both the spray head (brew water) and the dilution nozzle (bypass water).

🛠️ What You’ll Need

• A measuring pitcher (minimum 64 oz, though 130 oz is better for dilution).

• The brew funnel and spray head must be clean and free of lime scale before starting.

Part 1: Calibrate the Spray Head (Brew Flow)

This measures the water coming through the tea leaves in the funnel.

1. Enter Programming Mode: Press and hold the right hidden button (usually located to the right of the digital display or near the BUNN logo/trademark symbol) for about 5 seconds until the screen displays CALIBRATE FLOW?.

2. Select Yes: Press the button under YES. The screen will display SPRAYHEAD CAL?. Press YES again.

3. Prepare the Machine: Place an empty brew funnel into the rails and place your measuring pitcher underneath it.

4. Start the Test: When the screen says CONTAINER READY?, press YES. Press the BREW button.

   • The machine will dispense water for exactly 60 seconds.

5. Measure and Adjust: Once the 1-minute timer hits zero and the dripping stops, look at the amount of water in your pitcher.

   • The screen will show a number (e.g., 15.0 OZ/M).

   • Use the (+) or (-) buttons to change the number on the screen to match the actual amount you measured in your pitcher.

6. Save: Press DONE. The machine now knows exactly how much water flows through the spray head per minute.

Part 2: Calibrate the Dilution (Bypass Flow)

This measures the cold water that bypasses the tea leaves to fill the dispenser.

1. Navigate to Dilution: From the main calibration menu, press the hidden button until you see CALIBRATE DILUTE?.

2. Select Yes: Press YES.

3. Prepare the Machine: Move your pitcher so it is directly under the dilution nozzle (the separate nozzle usually located behind or to the side of the spray head).

4. Start the Test: Press YES at the CONTAINER READY? prompt, then press the BREW button.

   • The machine will again dispense water for 60 seconds.

5. Measure and Adjust: Check the total ounces in your pitcher.

   • The screen will display its current programmed dilution flow rate (e.g., 60.0 OZ/M).

   • Use the (+) or (-) buttons to adjust the screen to match your measured volume.

6. Save: Press DONE.

Part 3: Exit & Verify

1. Exit Programming: Press the hidden button repeatedly (or the BACK button) until you return to the main READY TO BREW screen.

2. Pro-Tip (Maintenance): If your measurements are significantly lower than the factory defaults (usually around 15oz for spray and 60-70oz for dilution), check for a clogged spray head or a kinked water line before finishing.

Warning: Be careful when handling the water during the Spray Head calibration; it is dispensed at brewing temperature (200°F/93°C) and can cause burns.

Use this guide to help diagnose and troubleshoot in store. Please always report this to your Store Supervisor and/or Ops Leader so they can reach out for maintainance if needed.

🧊 Phase 1: The "First Look" Checklist

Before opening the mechanical housing, check these external factors that cause 50% of cooling failures.

• Power & Controller: Is the digital display on? If it’s blank, check the GFC/Outlet. If it says "OFF" or "STBY," someone may have accidentally held the power button while cleaning.

• The "Airflow" Rule: Is the cooler stuffed to the brim? Reach-ins require internal air circulation. If containers are blocking the Evaporator Fans (usually at the top/back), the bottom of the unit will stay warm.

• Clearance: Reach-ins breathe from the bottom or the top. Ensure there are at least 4–6 inches of space between the cooler and the wall/other equipment.

🛠️ Phase 2: Common Symptoms & Fixes

1. The Unit is Running but Not Cold

• Dirty Condenser Coils: This is the #1 cause of failure. Dust and grease from the kitchen coat the coils, preventing heat from escaping.

  • Fix: Unplug the unit, find the coil grate (bottom or top), and use a vacuum or stiff brush to remove the "blanket" of dust.

• Frosted Evaporator: Look inside at the fans. Do you see ice buildup? This happens if the door is left cracked or a seal is leaking.

  • Fix: Manual Defrost. Turn the unit off for 4–24 hours with the doors open to melt the internal ice block.

2. Rapid "Cycling" (Turning On and Off Frequently)

• Worn Door Gaskets: If the rubber seal is torn or brittle, cold air escapes.

  • The Paper Test: Close the door on a piece of paper. If you can pull the paper out with no resistance, your seal is blown.

  • Fix: Clean the gasket with warm soapy water (syrup spills make them stick and tear). If torn, they must be replaced.

3. Water Pooling at the Bottom

• Clogged Drain Line: Every cooler has a hole to drain condensation. In boba shops, spilled powders or liquids can clog this.

  • Fix: Locate the drain hole inside and flush it with a mixture of warm water and a capful of bleach to clear slime/mold.

🔊 Phase 3: The "Sound" Test

Listen closely to the machine to identify the failing part:

Sound - Meaning: Action

Loud Clicking - Start Relay / Compressor: The compressor is trying to start but failing. Call a Pro.

High-Pitched Squeal - Fan Motor: A bearing is going bad in the evaporator or condenser fan.

Bubbling / Hissing - Refrigerant Leak: You have a hole in the lines. Let your Ops Leader know so we can get maintainance.

Silence (but lights are on) - Thermostat: The sensor thinks it's already cold. May need a sensor replacement.

🥤 Sealer Machine Troubleshooting Guide

1. The Machine Isn't Powering On

• Check the Source: Ensure the plug is pushed firmly into the outlet and the machine’s power switch is in the ON position.

• Fuse Check: Most machines have a small fuse compartment near the power cord entry. If there was a power surge, the fuse might be blown.

• Emergency Stop: Ensure the red Emergency Stop button hasn't been accidentally pressed. Twist it clockwise to release.

2. The Film Isn't Advancing (Or Skipping)

• Sensor Alignment: Look for the small electric eye (sensor) that reads the black marks on the film. If it’s dirty or misaligned, the film won't stop at the right spot. Clean it with a dry microfiber cloth.

• Spring Tension: Ensure the butterfly nuts on the film rollers are tightened correctly. If they are too loose, the film slips; too tight, and the motor struggles to pull.

• Film Direction: Double-check that the film is threaded under the sensor bar and over the rollers according to the diagram on the machine.

3. Cup Is Leaking or Has a Weak Seal

• Temperature Check: For standard PP (Polypropylene) cups, the temperature should usually be set between 160°C and 180°C. If it's too low, it won't bond; if it's too high, it will melt and warp the film.

• Clean the Heating Plate: Turn the machine off and let it cool completely. Use a damp cloth to wipe the circular heating element. Sugar or film residue on the plate creates gaps in the seal.

• Dry the Rim: If the rim of the cup is wet with tea or syrup, the film cannot stick. Ensure your baristas aren't overfilling.

4. The Film Is Sticking to the Heater

• Too Hot: Your temperature is likely set too high. Lower it by 5°C increments.

• Residue Buildup: Burnt film on the heating ring acts like glue. Use a non-metal scraper (like a plastic card) to gently remove residue once the machine is cool.

5. Error Codes (Common)

Code: Meaning - Fix

P01: Temperature Sensor Error - Restart machine; if it persists, the internal sensor may need replacement.

E00: Motor/Switch Issue - Check for film jams or obstructions in the cup tray path.

E01: Film Sensor Error - Clean the electric eye or check if the film has run out.