There is nothing more frustrating than unpredicted problems with your Bunn coffee maker when instead of a cup of coffee, you receive just steam or water. Quite often, coffee makers stop working if the one-way valve gets clogged, but there are also dozens of other possible problems.
Luckily, coffee maker repair typically isn’t a complicated task even for those who don’t have relevant experience. Try the troubleshooting tips from the tables below and see for yourself!

Bunn VPR VPS coffee maker troubleshooting

PROBLEMPROBABLE CAUSEREMEDY
Water is not hot1. Limit Thermostat or Thermal Cut-Off CAUTION - Do not eliminate or bypass limit thermostat/thermal cut-off. Use only BOM replace- ment part. Limit Thermostat - #29329.0001 Thermal Cut-off - #04776.0000Limit Thermostat or Thermal Cut-Off for testing procedures.
2. Control ThermostatControl Thermostat for testing procedures.
3. Tank HeaterTank Heater for testing procedures.
Spitting or excessive steaming1. Lime Build-up CAUTION - Tank and tank components should be delimed regularly depending on local water conditions. Excessive minerai build-up on stainless Steel surfaces can initiate corro- sive reactions resulting in serious leaks.Inspect the tank assembly for excessive lime deposits. Delime as required.
2. Control ThermostatControl Thermostat for testing procedures.
Dripping from sprayhead1. Lime Build-up CAUTION - Tank and tank components should be delimed regularly depending on local water conditions. Excessive minerai build-up on stainless steel surfaces can initiate corro- sive reactions resulting in serious leaks.Inspect the tank assembly for excessive lime deposits. Delime as required.
1. DispenserThe dispenser must be completely empty before starting a brew cycle.
Beverage overflows dispenser1. Filter TypeBUNN® paperfilters must be used for proper extraction.
Weak beverage2. Coffee GrindA fine or drip grind must be used for proper extraction.
3. SprayheadA six-hole stainless steel spray head must be used for proper extraction.
4. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by gentle shaking.
5. Water TemperaturePlace an empty funnel on an empty dispenser beneath the sprayhead. Pour-in a pitcher of tap water and check the water temperature im- mediately below the sprayhead with a thermometer. The reading should not be less than 195°F. Adjust the control thermostat to increase the water temperature. Replace if necessary.
Dry coffee grounds remain in the funnel1. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by gently shaking.
Brewer is making unusal noises1. Tank HeaterRemove and clean lime off the tank heater.
Cool beverage serving temperature1. ON/OFF Warmer SwitchON/OFF Warmer Switch for testing procedures.
2. Warmer Element(s)Warmer Element(s) for testing procedures.

Bunn Smart Wave Series coffee maker troubleshooting

RED LED FLASHESDISPLAYDESCRIPTIONACTION
1ER 1TEMP SENSOR SHORTEDCALL SERVICE
2ER 2TEMP SENSOR OPENCALL SERVICE
3ER 3HEATING TOO LONGCALL SERVICE
4ER 4REFILL TOO LONGCHECK WATER SUPPLY
5ER 5HIGH TANK LEVEL-DURING BREWDELIME
6ER 6CHECK "ENABLE BREW ON/OFF SWITChCHECK SWITCH
7ER 7CHECK "BREW A7LARGE" SWITCHCHECK SWITCH
8ER 8CHECK "BREW B7LARGE" SWITCHCHECK SWITCH
Not ApplicableER 9CHECK "HIDDEN" SWITCHCHECK SWITCH

Bunn SINGLE SERVE POD BREWER coffee maker troubleshooting

PROBLEMSUGGESTIONS
Brew Button Flashes Red• Internal hot water tank must be filled with water.
Brew Button is Red• Your mochine is brewing. Press the Brew Button again to stop the brew process.
Indicator Light is Green• Water is hot and ready to brew.
Indicator Light is Red• Water is heating.
Indicator Light Flashes Red• The Brew Button was pressed but the water is heating. Wait for indicator light to turn green and press Brew Button again.
Indicator Light Flashes Green• Add water. NOTE: Make sure that a cup is positioned on the Drip Tray under the Pod Drawer prior to pushing Brew Button.
• If water with low mineral content such as distilled water is used, the sensors may not detect the water. Tip the brewer to drain the water out of the Pour-ln Bowl and add tap water, drinking water or bottled water with a higher mineral content.
Indicator Light Flashes Red and Green• Pod Drawer is not fully inserted. Press in the Pod Drawer to lock into place.
Pulse Button is Red• The Pulse option is activated. Press the Pulse Button again to deactivate.
Brewer doesn't turn on• Make sure brewer is plugged into a working outlet.
• Press Brew Button to begin brew (Brew Button will be illuminated).
Coffee/tea is not brewing• Make sure brewer is plugged into a working outlet.
• Make sure brewer is filled with water. The hot water tank needs to be filled to begin brewing (indicator light will flash green).
• Make sure Pod Drawer is fully inserted (the indicator light will alternately flash red and green if it is not fully inserted).
• If indicator light flashes red. brewer is heating water to proper brew temperature in approximately 2 minutes. When the light is green, press Brew Button.
• Press Brew Button to begin brew (Brew Button will be illuminated).
Takes too long to brew• Mineral deposits may be present in your brewer. See Deep Cleaning
and Cleaning the Sprayhead
Brewer only brews water• Make sure a pod is in the Pod Drawer.
Water speed varies during brew• The Pulse Brew Button has been pressed. During the brew, water flow will vary to properly steep tea or for stronger coffee.
Water leaks out around the Sprayhead• The Sprayhead may be clogged, loose or the seal may be damaged. Please refer to Cleaning the Sprayhead. Reassembling the Sprayhead/ Seal and Inspecting the Sprayheod Seal on pages 6 and 7.
The Pod Holder will not come out of the brewer• The pod in the Pod Drawer may be swelled to a point where the drawer does not slide out easily. Wait 10 minutes for the pressure to drop and try carefully removing the Pod Drawer ogain.
Water leaks out around the. Pod Drawer• Make sure the pod is fully seated in the Pod Drawer cavity.
Off taste is detected• Perform Basic Cleaning and Deep Cleaning
• Remove used pods from pod drawer after each brew. Do not leave used pods in the pod drawer for extended periods of time.

Bunn OL coffee maker troubleshooting

ProblemProbable CauseRemedy
Equipment will not operate.1. No power or incorrect voltage(A) Connect the brewer to the power source.
(B) Check the terminal block for the proper voltages.
(C) Check circuit breaker/fuse.
Brew cycle will not start.1. No waterCheck plumbing and shut-off valves.
2. Water Strainer(A) Direction of flow arrow must be poinling towards brewer.
(B) Remove the strainer and check for obstructions. Clear or replace.
3. Water Level Switch and Overflow Safety SwitchRefer to Service Water Level Switch and Overflow Safety Switch for testing procedures.
Brew cycle will not start, (cont.)4. On/Off Brew Station Warmer SwitchRefer to Service On/Off Brew Station Warmer Switch for testing procedures.
5. Start SwitchRefer to Service Start Switch for testing procedures.
6. RelayRefer to Service Relay for testing procedures.
7. Solenoid ValveRefer to Service Solenoid Valve for testing procedures.
Water flows into fill basin continuously (On/Off brew station warmer switch ’OFF*).1. Solenoid ValveRefer to Service Solenoid Valve for testing procedures.
Water flows into fill basin continuously (On/Off brew station warmer switch "ON*).1. Start SwitchRefer to Service Start Switch for testing procedures.
Water is not hot.1. Limit Thermostat. Do not eliminate or bypass limit thermostat. Use only B.O.M. replacement part #29329.1000Refer to Service Limit Thermostat for testing procedures.
2. Control ThermostatRefer to Service Control Thermostat for testing procedures.
3. Tank HeaterRefer to Service Tank Heater for testing procedures.
Decanter warmer is not hot.1. Warmer Switches(A) The Warmer Switches must be in the ON position for the warmer to operate.
(B) Refer to Service Warmer Switch (es) for testing procedures.
2. Decanter WarmersRefer to Service Warmers for testing procedures.
Spitting or unusual steaming from sprayhead.1. Control ThermostatRefer to Service Control Thermostat for testing procedures.
2. Lime build-up. Tank and tank components should be delimed regularly depending on local water conditions. Excessive mineral build-up on stainless steel surfaces can initiate corrosive reactions resulting in serious leaks.Inspect the tank assembly for excessive lime deposits. Delime as required.
Warmer plates too hot, solenoid coil smoking, or water in tank heats excessively fast.1. Brewer wired to wrong voltage
Inconsistent beverage level in decanter.1. Improper water pressureCheck the operating water pressure to the brewer. It must be between 20 and 90 psi.
2. Syphon systemWater should flow freely from the sprayhead and then stop abruptly. The brewer must be level from frontto-back to syphon properly.
Dripping from sprayhead.1. Syphon systemWater should flow freely from the sprayhead and then stop abruptly. The brewer must be level from frontto-back to syphon properly.
2. Solenoid ValveRefer to Service Solenoid Valve for testing procedures.
Beverage overflows decanter.1. Beverage left in decanterThe brew cycle should be started only with an empty decanter under the funnel.
Weak beverage.1. Type of paper filtersBUNN® paper filters should be used for proper extraction.
2. CoffeeA sufficient quantity of fine or drip grind coffee should be used for proper extraction.
3. SprayheadB.O.M. sprayhead #01082.0000 should be used to properly wet the bed of ground coffee in the funnel.
4. Funnel loadingThe BUNN® paper filter should be centered in the funnel and the bed of coffee leveled by gentle shaking.
5. Water temperaturePlace a funnel over an empty decanter on the warmer beneath the sprayhead. Place the On/Off brew station warmer switch in the upper position, press the start switch, and check the water temperature immediately below the sprayhead with an accurate thermometer. The reading should not be less than 195° F. Adjust the control thermostat slightly clockwise to increase the water temperature.
Brewer is making unusual noises.1. Solenoid ValveThe nut on top of the solenoid valve must be tight or it will vibrate during operation.
2. Plumbing linesPlumbing lines should not rest on the counter top.
3. Water supply(A) The brewer must be connected to a cold water line.

Bunn coffee maker BTX B troubleshooting

ProblemSuggestions
Coffee not coming out• Initial set up required.
• Make sure lid is closed.
• Evaporation can occur overtime - reservoir may need to be refilled.
• Requires a minimum of 4 cups (20 oz) to begin brewing.
• Check sprayhead holes, clean if necessary.
Brewed only partial decanter• Evaporation can occur overtime - reservoir may need refilled.
• Some water is always absorbed by the coffee grounds and filter. You may need to adjust water input accordingly.
Funnel is overflowing• Use BUNN paper filters.
• Sprayhead is missing.
• Decaffeinated, fine grind coffee or softened water is used. See bottom of to order correct sprayhead or paper filters.
Coffee is cold• Plug in brewer and turn on vacation switch on side of brewer. Allow 15 minutes for water to heat to proper temperature.
Coffee is not staying hot• Warmer switch should be in the “on” position. (BX, GRX, NHBX)
• If using a BTX with thermal carafe, pre-heating will increase the time your coffee will stay warm.
Loud rumbling noise• Normal while water is heating.
• May be time to delime.
Waterflow begins before lid is closed• Make sure lid is fully open.
• Brewer is not designed to hold water in upper tray for an extended period of time.
• Remove top lid to ensure rocker arm is snapped in place and rubber stopper area is thoroughly cleaned.
Deliming tool doesn’t go in all the way• Refer to deliming instructions (step 3)
Brewer leaks• For repair information, go to www.bunn.com, Home Coffee Brewers or call 800-352-2866.

Bunn CDBCF Airpot coffee maker troubleshooting

FLASHESCAUSETHINGS TO CHECK
1Dry Plug - In Fault - Sheath of temperature probe dry for 10 minutes after power-upWater Pressure
Temperature probe wiring
Rll valve wiring, function, & strainer
Green wire between tank and circuit board
2Low Tank Level Fault - Level probe dry for 7 minutes after fill valve is energizedWater pressure Level probe wiring Temperature probe wiring Rll valve wiring, function, & strainer
3Low Water Temperature Fault - Sensor in tank is calling for heat for 30 minutes or moreTank heater wiring & function Temperature probe wiring
4Tank Sensor Disagreement - Level probe detects water, but dry plug-in probe dryTemperature probe wiring Level probe wiring
Green wire between tank and circuit board
5Temp Sensor Out-of-Range - HighSensor not connected to circuit board
6Temp Sensor Out-of-Range - LowSensor wires shorted together or to chassis

Bunn HG coffee maker troubleshooting

PROBLEMSUGGESTIONS
Brewer does not turn on• Make sure brewer is plugged into a working outlet.
• Press the On/Off button to begin brew (red light will be illuminated).
Coffee is not brewing• Make sure brewer is plugged into a working outlet.
• Make sure brewer is filled with water. A minimum of 4 cups (20 oz.) is needed to begin brewing.
• Make sure brewer clock is set.
• Press the On/Off button to begin brew (red light will be illuminated).
• Check to see if Auto-Start time was programmed accurately.
Brew time is longer than usual• Check sprayhead holes for debris. Clean sprayhead and perform deep cleaning.
Brew funnel overflows• Be sure filter basket is properly inserted.
• Use BUNN paper filters - they are taller to prevent overflow.
• Be sure sprayhead is in place.
• If overflow continues, contact BUNN for a flow restrictor sprayhead.
Warmer plate stays on after brewing phase• Warmer plate automatically shuts off after 2 hours. To shut off manually, push the On/Off button (red light will turn off).
Programmed• Make sure AM/PM was accurately selected.
Auto-Start did not work• Reprogram for Daylight Savings Time or a power outage if needed.
• Make sure Auto-Start button is illuminated.
Digital display flashes between time and ‘CLE’• Perform deep cleaning.
Rumbling noise• Normal while water is heating.
• Will occur if you pour fresh water into unit immediately after brewing.
• Will occur if you pour fresh water into unit when the warmer is still on from previous brew.

Bunn CWT 15-APS coffee maker troubleshooting

PROBLEMPROBABLE CAUSEREMEDY
Brew cycle will not start1. ON/LOWER Switch is off.Turn on switch.
2. No power(A) Turn on main power switch.
(B) Check that the power cord is securely plugged into outlet.
(C) Check circuit breakers or fuses.
3. No water(A) Water lines and valves to the brewer must be open.
(B) Check for plugged water filter
Water is not hot1. Heater switch turned off.Turn on switch
Inconsistent beverage level1. Lime Build-up(A) Use deliming spring.
(B) Clean sprayhead.
2. Water Pressure fluctuating.Have a pressure regulator In- stalled.
Consistently low or high bever- age level.1. Timer adjustment.Adjust timer.
Spitting or excessive steaming1. Lime Build-up(A) Use deliming spring.
(B) Clean sprayhead.
Dripping from sprayhead1. Syphon SystemThe brewer must be level or slightly lower in front to syphon properly.
Brew cycle starts when ON/ LOWER Switch is turned on.Auxiliary brew start switch on TWINS inadvertently activated.Move objects away from brewer.
Weak beverage1. Filter TypeBUNN® paperfilters must be used for proper extraction.
2. Coffee GrindA fine or drip grind must be used for proper extraction.
3. SprayheadA clean spray-head must be used for proper extraction.
4. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of ground leveled by gentle shaking.
5. Water TemperaturePlace an emptyfunnel on an empty dispenser beneath the sprayhead. Initiatea brew cycle and check the water temperature immediately below the sprayhead with a ther- mometer. The reading should not be less than 195°F (76°C). Adjust the control thermostatto increase the water temperature. Replace if necessary.
Dry coffee grounds remain in the funnel1. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by gently shaking.
2. SprayheadA clean spray-head must be used for proper extraction.

Bunn CW-APS coffee maker troubleshooting

PROBLEMPROBABLE CAUSEREMEDY
Brew cycle will not start (CWT- APS, CWTF-APS, CWT-TS, CWTF- TS, CWT-TSR &CWTF-TSR)1. No waterWater lines and valves to the brewer must be open.
2.Nopowerorincorrectvoltageto the brewer(A1) Check the terminal block for 120 volts across the black and white terminals on two wire 120 volt brewers.
(A2) Check the terminal block for 120 volts across the red and white terminals and the black and white terminal on three wire 120/240 volt brewers.
(A3) Check the terminal block for 200 volts on ’B Series" brewers or 240 volts on ’A Series" brewers across the red and black termi- nals.
(A4) Check the terminal block for 100 volts on ’B Series" brewers across the white and black terminals.
(B) Check circuit breakers or fuses.
Brew cycle will not start (cont.) (CWT-APS, CWTF-APS, CWT-TS, CWTF-TS, CWT-TSR &CWTF- TSR)3. ON/OFF SwitchRefer to Service - ON/OFF Switch for testing.
4. Start SwitchRefer to Service - Start Switch for testing procedures.
5. TimerReferto Service-Timerfortesting procedures.
6. Solenoid ValveRefer to Service - Solenoid Valve for testing procedures.
7. Water strainer/flow control (.222 GPM)(A) Direction of flow arrow must be pointing towards brewer.
(B) Remove the strainer/flow con- trol and check for obstructions. Clear or replace.
Water is not hot1. Tank Heater SwitchRefer to Service - Tank Heater Switch fortesting procedures.
2. Limit Thermostat CAUTION - Do not eliminate or bypass limit thermostat. Use only BOM replacement part #29329.1000Refer to Service - Limit Thermostat for testing procedures.
3. Control ThermostatRefer to Service - Control Thermostat fortesting procedures.
4. Tank HeaterRefer to Service - Tank Heater for testing procedures.
Inconsistent beverage level in dis- penser1. Strainer /flow control (.222 GPM) (CWT-APS, CWTF-APS, CWT-TS, CWTF-TS, CWT-TSR & CWTF-TSR(A) Direction of flow arrow must be pointing towards the brewer.
(B) Remove the strainer/flow con- trol and check for obstruction. Clear or replace.
2. Syphon SystemThe brewer must be level or slightly lower in front to syphon properly.
3. Lime Build-up CAUTION-Tankand tankcompo- nents should be delimed regularly depending on local water condi- tions. Excessive mineral build-up on stainless steel surfaces can initiate corrosive reactions result- ing in serious leaks.Inspect the tank assembly for excessive lime deposits. Delime as required.
4. Water Pressure (CWT-APS, CWTF-APS, CWT-TS, CWTF-TS, CWT-TSR & CWTF-TSR)The water pressure to the brewer must be at least 20 psi (138 kPa).
Consistently low beverage level in the dispenser (CWT-APS, CWTF- APS, CWT-TS, CWTF-TS, CWT- TSR & CWTF-TSR)1. TimerTimer must activate solenoid for at least two minutes and fifteen seconds.
2. Strainer/flow Control (.222 GPM)(A) Direction of flow arrow must be pointing towards brewer.
(B) Remove the strainer/flow control and check for obstructions. Clear or replace.
Spitting or excessive steaming1. Lime Build-up CAUTION-Tankand tankcompo- nents should be delimed regularly depending on local water condi- tions. Excessive mineral build-up on stainless steel surfaces can initiate corrosive reactions result- ing in serious leaks.Inspect tank assembly for excessive lime deposits. Delime as required.
Weak beverage1. Filter TypeBUNN® paper filters must be used for proper extraction.
2. Coffee GrindA fine or drip grind must be used for proper extraction.
3. SprayheadA six-hole stainless steel spray- head must be used for proper extraction.
4. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of ground leveled by gentle shak- ing.
5. Water TemperaturePlacean empty funnel on an empty dispenser beneath the sprayhead. I nitiate a brew cycle and check the water temperature immediately below the sprayhead with a thermometer. The reading should not be less than 195°F. Adjust the control thermostat to increase the watertemperature. Replace if necessary.
Dry coffee grounds remain in the funnel1. Funnel LoadingThe BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by gently shaking.
Brewer is making unusal noises (CWT-APS, CWTF-APS, CWT-TS, CWTF-TS, CWT-TSR, CWTF-TSR)1. SolenoidThe nut on the solenoid must be tight or it will vibrate during operation.
2. Plumbing LinesPlumbing lines should not resting on the countertop.
3. Water Supply(A) The brewer must be connected to a cold water line.