my avalon bay ice maker just blinks 'add water' nonstop even though the reservoir is full, what gives?

Diagnosis

The "Add Water" blinking light on the Avalon Bay AB-ICE26S is triggered by a failure in the water level detection circuit. This model utilizes a magnetic float sensor—a small plastic cylinder that rises and falls with the water level. Inside this float is a magnet that triggers a reed switch when it reaches the "full" threshold. When the light blinks despite the reservoir being full, it means the reed switch is not being activated, either because the float is physically stuck in the "down" position or because mineral buildup (scale) has created a friction lock between the float and its guiding sleeve. In many cases, this is caused by "hard water" deposits. Calcium and magnesium from your tap water crystallize on the smooth walls of the sensor chamber, creating a gritty layer that prevents the float from gliding upward. If the float cannot rise to the top of the sensor shaft, the control board assumes the tank is empty and halts the ice-making cycle to prevent the pump from running dry and burning out. You can confirm this by looking through the reservoir window; if the float is sitting low while the water is high, you have a mechanical obstruction.

How to Fix It

To resolve this, you need to manually clear the obstruction and reset the sensor's movement. Follow these precise steps:

1. Power off the unit using the control panel and unplug the power cord from the wall outlet to ensure no electrical current is running to the sensor.
2. Remove the ice basket and lift the water reservoir tank completely out of the machine to expose the base.
3. Locate the sensor chamber—a small vertical tube located in the base of the unit where the water enters the pump system.
4. Using a clean cotton swab or a soft-bristled brush, gently push the plastic float down and let it snap back up. Repeat this 10-15 times to break any mineral bonds or dislodge trapped debris.
5. If the float feels "sticky," dip the cotton swab in a mixture of 50% white vinegar and 50% warm water. Rub this solution around the edges of the float and the inner walls of the sensor sleeve to dissolve calcium deposits.
6. Rinse the sensor area with a small amount of distilled water to remove any vinegar residue.
7. Reinsert the reservoir, ensuring it seats firmly and flush against the base.
8. Plug the unit back in and press the Power button. The "Add Water" light should extinguish within 5-10 seconds as the sensor registers the water level.

If That Didn't Work

• Deep Descaling Cycle: If the float is still sticking, the internal plumbing may be heavily scaled. Fill the reservoir with a commercial descaling solution or a strong vinegar mix. Run the machine for one full cycle, then let the solution sit in the reservoir for 2 hours without powering the unit on. This allows the acid to eat through the mineral buildup surrounding the sensor.
• Check for Air Locks: Sometimes an air bubble gets trapped in the sensor housing, preventing the float from reacting accurately. Tilt the machine gently forward and backward (about 15 degrees) while the reservoir is installed to release trapped air.
• Inspect the Reservoir Seal: Ensure the rubber gasket at the bottom of the water reservoir is not warped or missing. If the seal is leaking, the water level in the sensor chamber may be dropping faster than the tank level, triggering the alert prematurely.
• Hard Reset: Unplug the unit for exactly 30 minutes. This clears the volatile memory of the control board and forces a fresh hardware poll of the sensors upon reboot.

Heads Up

• Use Filtered Water: To prevent future sensor failures, use filtered or distilled water. Tap water containing high mineral content is the primary cause of float-sensor malfunctions in the AB-ICE26S.
• Weekly Cleaning: Run a vinegar-based cleaning cycle once every two weeks to prevent calcium buildup from seizing the float mechanism.
• Avoid Harsh Chemicals: Never use bleach or abrasive scouring pads inside the sensor chamber, as this can scratch the plastic and create more "catch points" for minerals to adhere to.
• Level Surface: Ensure the machine is on a perfectly level surface. If the unit is tilted, the float may lean against the side of the sleeve, increasing friction and causing false "Add Water" readings.