keeps getting stuck on 'priming' and never finishes, just shows the little water drop forever.

Diagnosis

The Breville Oracle Jet BES750BSS utilizes a high-pressure pump and an automated priming sequence to ensure the thermoblock is saturated before heating. When the machine hangs on the "priming" screen with the flashing water drop icon, it indicates that the pump is running, but the flow sensor is not detecting a sufficient volume of water passing through the system. This is typically caused by an airlock—a pocket of air trapped in the internal tubing that prevents the pump from creating the vacuum necessary to pull water from the reservoir. This failure often occurs after the machine has run completely dry, during the first setup, or if the water tank was removed while the pump was active. Because the Oracle Jet uses a sophisticated internal valve system to manage both the espresso group head and the steam wand, air can become trapped in the "T-junction" of the plumbing. If the pump cannot displace this air, the flow meter never triggers the "complete" signal, leaving the machine stuck in a loop. You can confirm this by listening closely: if you hear the pump humming loudly but no water is exiting the group head or steam wand, you have a classic airlock.

How to Fix It

To clear the airlock and force the machine to complete the priming cycle, follow these precise steps:

1. Ensure the water tank is filled to the "MAX" line with filtered water. This provides the maximum head pressure to help push air out.
2. Remove the water tank and inspect the magnetic float (the small plastic piece that moves up and down in the tank). Ensure it moves freely and isn't stuck at the bottom.
3. Re-insert the tank firmly, ensuring it clicks fully into the base to engage the valve.
4. Power the machine off and then back on. When the "priming" screen appears, immediately press the "Steam" button or the "Hot Water" button. This diverts the water path and often forces air out through the steam wand more efficiently than the group head.
5. While the pump is running, gently lift the water tank up and down (about 1 inch) several times. This creates a "pulsing" effect in the intake valve that can break the surface tension of an air bubble.
6. Once water begins to flow steadily from the steam wand, let it run for 10 seconds, then press the button again to stop. The machine should now recognize the flow and clear the priming screen.

If That Didn't Work

• Manual Valve Reset: Turn the machine off. Remove the water tank and the water filter holder. Instead of the filter, place a small piece of clean, lint-free cloth over the intake valve at the bottom of the machine and press down firmly for 5 seconds. This can sometimes "seat" the valve if it was stuck partially open, allowing air to leak in. Reinstall the tank and try priming again.
• The "Hot Start" Method: If the machine is cold, the air pockets are larger. Let the machine warm up for 10 minutes. Even if it's stuck on priming, the thermoblock may still be heating. Heat expands the air, making it easier for the pump to push the bubble through the system. Attempt the "Steam" button prime again after the machine is warm.
• Water Tank Bypass: If you are using the included charcoal filter, remove it entirely. A clogged or improperly seated filter creates too much resistance for a pump struggling with an airlock. Try to complete the priming cycle with just plain water in the tank; if it works, the filter was the bottleneck.
• Hard Reset: Unplug the machine from the wall outlet for a full 60 seconds. This clears the volatile memory of the control board and resets the flow sensor logic. Plug it back in and immediately initiate the priming sequence.

Heads Up

• Avoid Dry Running: Never let the water tank drop below the minimum line. Once air enters the BES750BSS pump, it is significantly harder to remove than in simpler machines due to the complex internal routing.
• Filter Maintenance: Replace the water filter every 2 months or 40 liters. A saturated filter can restrict flow enough to trigger a "priming" error even when the tank is full.
• Water Quality: Use filtered water to prevent calcium buildup in the flow meter. If the flow meter becomes coated in scale, it may fail to detect water movement, leading to a permanent "stuck on priming" state.
• Tank Seating: Always ensure the tank is pushed straight down. If it is tilted, the valve won't open fully, and the pump will suck air instead of water.