BUNN Slush Machine Message HOPPER LIGHTS FLASHING: Low Product
HOPPER LIGHTS FLASHING means the hopper is low on product. On Autofill units the bag-in-box may be empty. Refill the hopper to clear the error, or replace the bag-in-box if it is empty.
Low: an operator prompt that clears when the hopper is refilled.
- Code
- HOPPER LIGHTS FLASHING
- Maker
- BUNN
- Equipment
- Slush & frozen drinks
- Applies to
- Ultra NX frozen beverage dispenser
What does BUNN HOPPER LIGHTS FLASHING mean?
The Ultra NX dispenser watches the product level in the hopper above each barrel. When the level falls low, the hopper lights flash to ask for a refill. The Use and Care Guide says the hopper is low on product, and that on Autofill units the bag-in-box may be empty. Refilling the hopper clears the error, and replacing the bag-in-box clears it on an Autofill unit. Running with a low hopper starves the barrel, which can lead to thin or icy product and, if it continues, to the refill error or the product mix message. The lights are an operator prompt and not a malfunction. If the lights flash soon after a refill, check that the product is reaching the sensor, and that the bag-in-box line is connected and not kinked. The guide does not list part failures for this message. A hopper that runs dry during service leaves the barrel short of mix, so the product can come out thin or icy until the barrel is full again.
Affected models and control systems
BUNN Ultra NX frozen beverage dispensers. Other BUNN frozen drink machines use different messages.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Hopper lights flashing
- Hopper level low
- Bag-in-box empty on Autofill units
Possible causes
Likely causes — what usually sits behind HOPPER LIGHTS FLASHING on this control. A technician confirms which one it is before any part is replaced.
- Hopper low on product
- Bag-in-box empty (Autofill)
- Bag-in-box line kinked or not connected
- Level sensor covered by sticky product
- Heavy use during a busy period
Safe checks before calling for service
- Look at the hopper and add product to the level mark.
- On an Autofill unit, check the bag-in-box and replace it if empty.
- Check that the bag-in-box line is connected and not pinched.
- If the lights keep flashing after a refill, note the side and tell the technician.
How a technician diagnoses HOPPER LIGHTS FLASHING
- Read the lights and confirm the hopper level.
- Check the bag-in-box connector and line.
- Check the level sensor for residue.
- Check the refill pump or valve operation.
- Replace the part that fails.
- The refill pump is electrically driven.
- Product lines can leak sugar solution onto electrical parts.
- Level sensing is part of the control circuit.
How HOPPER LIGHTS FLASHING differs from similar codes
HOPPER LIGHTS FLASHING is low product. The REFILL ERROR message is a refill process error that needs a button press to clear.
Technical reference
- Maker documentation
- BUNN owner support
- Edition
- 58028.0000 B 2/22
- Models / control
- Ultra NX frozen beverage dispenser
- Section
- Warnings & Error Messages table, side 1
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related BUNN slush & frozen drink error codes
How do I clear it?
Refill the hopper, or replace the bag-in-box.
Why does it flash after a refill?
The product may not be reaching the level sensor, the hopper may not be filled to the mark, or a bag-in-box line may be kinked. Recheck the fill level and the line before calling.
Is it the same as the refill error?
No. The refill error flashes the hopper lights too, but it needs the Left Dot pressed for 3 seconds to clear. This message clears by refilling.
Need help with BUNN HOPPER LIGHTS FLASHING?
A technician confirms the cause on site and gives you the price in writing before any work starts.