Bunn Slush Machine FILTER NEEDS !!!CLEANING!!!: Freezing Stopped
FILTER NEEDS !!!CLEANING!!! Is the serious version of the filter message on the older ULTRA machines. The hot gas sensor has passed 250 F and the machine has stopped freezing to protect itself. Clean the screen, check the air space, and keep an eye on the product, since it will warm in the barrel while freezing is off.
High: the machine has stopped freezing and the product in the barrel is warming until the cause is fixed.
- Code
- FILTER NEEDS !!!CLEANING!!!
- Maker
- BUNN
- Equipment
- Slush & frozen drinks
- Applies to
- ULTRA-1 / ULTRA-2 frozen drink dispenser
What does BUNN FILTER NEEDS !!!CLEANING!!! mean?
The ULTRA-1 and ULTRA-2 have two alarm stages for refrigeration heat. At 220 F on the hot gas sensor the display shows the plain message. If the temperature keeps rising and passes 250 F, the control moves to this version, with the exclamation marks, and shuts down freezing to protect the compressor. The exclamation marks matter because the barrel is no longer being cooled. Product left in it will warm toward room temperature, and in a food service setting that is a quality and safety question, not just an inconvenience. A badly clogged rear filter is the usual way to reach this stage, since the condenser has almost no air. Fins packed with dirt behind the filter, a refrigerant charge that has slowly dropped and a hot gas sensor that reads too high are the other manual causes. Cleaning the filter often brings the machine back, but it is worth checking the product before serving another cup.
Affected models and control systems
This page covers the older Bunn ULTRA-1 and ULTRA-2 frozen drink dispensers. The Ultra NX words its overheating message differently.
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
- Display shows FILTER NEEDS !!!CLEANING!!! And the barrel stops freezing
- Product in the barrel gets thinner and warmer
- Compressor is not running although the machine is powered
Possible causes
Listed in BUNN's documentation
- A rear filter so clogged that air barely passes
- Condenser fins packed with dirt behind the filter
- A refrigerant charge that has dropped over time
- A hot gas sensor that reads too high
Other likely causes — what usually sits behind FILTER NEEDS !!!CLEANING!!! on this control. A technician confirms which one it is before any part is replaced.
- A filter that was cleaned for the first alert and then left for months, so the second stage was reached in a single hot afternoon
- Grease from a nearby fryer baked onto the condenser fins where soap and water cannot reach
- A leak that has let the charge fall slowly, so the compressor runs hotter and longer each summer
Safe checks before calling for service
- Clean the filter or rear screen with soapy water or compressed air.
- Check the air space around the machine and move anything blocking it.
- Keep an eye on the product, since freezing is off. Check its temperature before serving it.
- If the message stays after cleaning, switch the machine off and call us. Note the time it first appeared.
How a technician diagnoses FILTER NEEDS !!!CLEANING!!!
- Read the display and confirm which barrel and which stage of the message is active.
- Inspect the filter, condenser fins and fan for blockage.
- Read the hot gas sensor temperature and compare it with a gauge reading on the refrigerant line.
- Check refrigerant pressures and the system for a leak.
- Replace the sensor only after the gauge reading shows that it is wrong.
- Product left in the barrel warms while freezing is off, so deciding whether it is still safe to serve takes a temperature check.
- Cleaning behind the filter and checking refrigerant charge need panels off, gauges and refrigerant certification.
- If the cause is lost refrigerant, no amount of filter cleaning will bring the machine back.
How FILTER NEEDS !!!CLEANING!!! differs from similar codes
The plain FILTER NEEDS CLEANING message appears first at 220 F. This one appears at 250 F and stops freezing.
Technical reference
- Document
- ULTRA-1/ULTRA-2 Service & Repair Manual 41084.0000D, Troubleshooting p.19-21
- Maker documentation
- BUNN owner support
- Edition
- 41084.0000D 03/13 (copyright 2009 Bunn-O-Matic Corporation)
- Models / control
- ULTRA-1 / ULTRA-2 frozen drink dispenser
- Section
- Troubleshooting flowcharts: Torque Sensor Error p. 19, Temperature Sensor Error p. 20, Clean Filter Messages p. 21
- 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
Can I keep serving after FILTER NEEDS !!!CLEANING!!! Appears?
Only if you can confirm the product is still cold enough. Freezing is off, so it will keep warming.
Will the machine start freezing again on its own?
It may once it cools and the airflow is restored, but if it does not, the cause is deeper than the filter.
Why did it jump to this message so fast?
A blocked filter can raise heat quickly on a hot day. Low refrigerant or a high reading sensor can do the same.
Need help with BUNN FILTER NEEDS !!!CLEANING!!!?
A technician confirms the cause on site and gives you the price in writing before any work starts.