Bunn Fill Time Too Long Error Code
Tank refill timed out — the brewer could not fill the tank within the allowed time and shut down.
Source: Bunn/BU-AXIOM_sm.pdf
What does Bunn Fill Time Too Long mean?
On AXIOM digital brewers, the control board monitors how long the inlet (refill) valve runs to fill the hot tank. If the water level probe does not sense a full tank within the allowed window, the display reports Fill Time Too Long and stops the refill. The brewer shuts down to protect the tank heaters, since they will not energize until water grounds the level probe.
Symptoms
- Display reads "Fill Time Too Long"
- Tank does not refill or fills very slowly
- Brewer will not reach ready and will not brew
- Water heaters stay off because the tank is not full
Common causes
- Water shut off to the brewer
- Supply line too small or obstructed
- Inlet solenoid (refill valve) failure
- Control board failure
- ON/OFF switch is OFF
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Diagnostic steps
Confirm the brewer is switched on
Make sure the ON/OFF switch is in the ON position and the indicator is lit. If the switch is OFF the refill circuit will not run.
Verify the water supply
Check that the water supply shut-off to the brewer is fully open. A closed or partially closed valve starves the refill circuit.
Inspect the supply line for restriction
Check that the inlet supply line is not undersized, kinked, or obstructed. Replace or repair the line as needed so it can deliver adequate flow.
Test the inlet solenoid (refill valve)
If water and supply are good, check the inlet solenoid valve for failure. Replace or repair the valve if it does not open.
Check the control board
If supply, switch, and valve are all good, the control board may have failed. Replace or repair as needed, then re-test the fill cycle.
When to call a professional
Refill diagnostics involve live AC line voltage at the solenoid, control board, and terminal block, and Bunn warns that shorting terminals or applying external voltage can destroy the board. If clearing the obvious supply and switch problems does not restore filling, have a Bunn Authorized Service Representative test the inlet solenoid and control board. Solenoids must not be energized more than ten minutes without water flow or damage results.
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Other Bunn Error Codes
The tank water failed to reach the ready temperature within the allowed time, so the brewer shut down.
Tank water is below the ready temperature, so brewing is locked out until it heats up.
The temperature sensor circuit reads open — the probe or its wiring is disconnected.
The temperature sensor circuit reads shorted — the sensor wiring is shorted.
The brewer detected inaccurate water flow caused by heavy lime buildup and is asking for descaling/repair.
The brewer detected very low water flow caused by lime buildup and is asking for descaling/repair.
Maintenance message prompting the operator to delime the sprayhead, valve, and tank.