BUNN Coffee Brewer Message Temperature Too Low: Tank Heating
Temperature Too Low means the water in the tank has not reached the ready temperature. Wait for the brewer to heat, or disable the BREW LOCKOUT function if you need to brew before it is hot.
Low: it is normally a heating wait that clears on its own.
- Code
- Temperature Too Low
- Maker
- BUNN
- Equipment
- Coffee brewers
- Applies to
- New Infusion Series (ITB, ITCB, ITCB HV, ICB SH/DV/Twin) display message
What does BUNN Temperature Too Low mean?
The Infusion Series brewer will not make a drink until the tank water is at the ready temperature. The control reads the tank temperature, and while it is below the target, the display shows Temperature Too Low. This is normal after the brewer is switched on, after a long idle period, or after a large amount of water has been drawn and fresh cold water has entered the tank. The programming manual, in its Troubleshooting page, says to wait for the brewer to heat, or to disable the BREW LOCKOUT function, described on page 16. The lockout is what stops brewing at a low temperature, so turning it off allows a drink before the water is ready, with the risk of weak coffee. The only cause the manual lists is that the tank water is below the ready temperature. If the message does not clear after a reasonable time, it can lead to the Heating Time Too Long message, which indicates a heating failure.
Affected models and control systems
BUNN Infusion Series bean-to-cup brewers: ITB, ITCB and HV models, and the ICB and Twin. Other BUNN brewer lines use a different message list.
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
- Temperature Too Low on the display
- Brewer will not start a drink
- Water in the tank not yet hot
Possible causes
Listed in BUNN's documentation
- Tank water below ready temperature
Other likely causes — what usually sits behind Temperature Too Low on this control. A technician confirms which one it is before any part is replaced.
- Brewer just switched on or recovering from a busy rush
- Cold inlet water after a long idle period
- Heater taking longer than normal because of scale
Safe checks before calling for service
- Check that the brewer is switched on and give it time to heat.
- Look at the display to see whether the message clears.
- Avoid forcing brews through the BREW LOCKOUT setting unless you accept a cooler drink.
- If it stays on for a long time, note how long and tell the technician.
How a technician diagnoses Temperature Too Low
- Read the message and how long the brewer has been heating.
- Measure the tank temperature against the display.
- Check the tank heater and its supply.
- Check the temperature probe reading and wiring.
- Check the control output to the heater.
- The heater and its relay are line-voltage parts.
- The tank holds hot water and steam under heat.
- Scale removal and heater work require draining and disassembly.
How Temperature Too Low differs from similar codes
Temperature Too Low is a normal heating wait. Heating Time Too Long means the tank did not heat in the allowed time.
Technical reference
- Maker documentation
- BUNN owner support
- Edition
- 41581.0003 D 3/20; troubleshooting page stamped 41581.3 120210
- Models / control
- New Infusion Series (ITB, ITCB, ITCB HV, ICB SH/DV/Twin) display message
- Section
- Troubleshooting (cont.), p.32
- 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 coffee brewer error codes
Is Temperature Too Low an error?
Not necessarily. It is the normal message while the tank is warming.
What is BREW LOCKOUT?
A setting that stops brewing until the tank is at temperature. Disabling it allows cooler brews.
How long should I wait?
If it does not clear in a reasonable time, expect the Heating Time Too Long message.
Need help with BUNN Temperature Too Low?
A technician confirms the cause on site and gives you the price in writing before any work starts.