How to Clean a Dishwasher Float Switch

What the float switch does

The float switch is a safety and control device inside your dishwasher. It sits in a small well in the tub floor, usually in a corner near the front or back. When water enters, the float rises; when it reaches a set height, the switch tells the control board to stop filling. If the float is stuck down, water keeps flowing and the tub can overflow. If it is stuck up, the dishwasher may not fill at all or may fill far too little. In such cases, refer to our guides on dishwasher not filling and dishwasher overflowing.

The float itself is typically a hollow plastic cap that fits over a vertical stem. The stem contains a small mechanical switch or a reed switch. It needs no tools to inspect on most models, but you should always disconnect the dishwasher from power before touching any internal part.

Locating the float

Open the dishwasher and remove the bottom rack. Look for a cup-like cap, usually white or black, sitting in a recess in the floor. It may be near the front left, front right, or rear depending on the model. On some compact and countertop units, the float is next to the spray arm at the back. If you need guidance on finding it in a built-in, our best built-in dishwashers guide covers common layouts.

If you cannot find it, check your owner's manual. Most manufacturers provide a diagram of the tub components. Bosch and Fisher & Paykel, for example, list the float in their online manuals under the water fill section. You can also search the manual for the key parts by visiting the support pages of those brands.

Common causes of sticking

The most frequent cause of a stuck float is debris. Small bits of food, broken glass, or a stray olive pit can wedge between the float cap and the well wall. Grease and detergent residue can also form a sticky film over time. In areas with hard water, mineral scale can make the float hard to move. Learn more about keeping your dishwasher clean inside with our filter cleaning guide.

If the float is stuck down, the dishwasher keeps filling because the switch never triggers. If it is stuck up, the switch is already triggered, so the dishwasher thinks the tub is full and either does not fill or runs with almost no water.

These problems are more likely if you do not scrape dishes well before loading, or if you use too much detergent that leaves residue. ENERGY STAR advises scraping rather than rinsing dishes to save water, but even a quick scrape helps keep the tub and its sensors cleaner.

Cleaning steps

Start by turning off the dishwasher at the circuit breaker or unplugging it. Open the door and remove the bottom rack to give yourself clear access to the float and its well.

Lift the float cap straight up. In many models it simply pulls off; in others it is held by a small clip. Do not force it. If it does not come off easily, check the manual for the specific release method.

Once the cap is off, inspect the well. Remove any visible food pieces or debris with your fingers or a soft-bristle brush. Do not use metal tools that could scratch the tub or damage the switch housing.

Wipe the float cap and the well with a clean cloth dampened with warm water. If you see scale or a white film, use a cloth dipped in vinegar to dissolve it, then wipe again with plain water. Dry the parts before reassembly.

After cleaning, put the float cap back on and confirm it sits flat and moves up and down without resistance. You can test it by gently pressing it down and letting it spring back. It should move smoothly and return to its rest position. If the switch is damaged, you may need to replace the float switch.

• Disconnect power first.
• Remove the float cap and clear debris by hand.
• Wipe the cap and well with a damp cloth or vinegar.
• Reinstall and verify free movement.

Testing the switch

With the float cap back in place, manually lift the float to the top of its travel. You may hear a faint click as the internal switch actuates. Release it and confirm it returns to the bottom. Do this a few times to ensure smooth operation.

If the float moves freely and makes a clear click, the mechanical part is likely fine. If it does not click, or if the float feels gritty and does not move smoothly even after cleaning, the switch itself may be faulty. In that case, you may need to replace the float switch assembly. See our guide on how to replace a dishwasher float switch for a step-by-step procedure.

A quick functional test is to run a short cycle and watch the water fill. If the dishwasher fills to the correct level and then stops, and no water leaks, the float switch is working. If it overfills, or if it stops filling after only a small amount of water, the switch may still be stuck. In those cases, consult our troubleshooting guides for dishwasher not filling or dishwasher overflowing.

Preventive maintenance

To keep the float switch clean, follow a few habits. Scrape food off plates before loading, but do not rinse; ENERGY STAR points out that rinsing wastes water and modern dishwashers are designed to handle food residue. Use the recommended amount of detergent, and consider a rinse aid to reduce mineral deposits and improve drying.

Inspect the float area whenever you clean the dishwasher filter. A quick wipe of the float and well once a month is enough for most households. If you have hard water, a vinegar rinse cycle every few months can help prevent scale buildup on the float and other parts. See our dishwasher filter cleaning guide for more tips.

If you have a portable or countertop dishwasher, the float works the same way. The cleaning process is identical, though the float may be smaller and closer to the side wall. Refer to the manual for your specific model if the float location is not obvious. For portable options, our best portable dishwashers guide can help you choose a model with easy access.

What to pick for your use

Questions

How often should I clean the dishwasher float switch?

A monthly check is a good habit, especially if you have hard water or often run heavy loads. If you notice filling problems, clean it right away. For related maintenance, see our filter cleaning guide.

Can I use vinegar to clean the float switch?

Yes. Vinegar dissolves mineral scale and grease. Use a cloth dampened with vinegar to wipe the float cap and its well, then rinse with water.

What happens if the float switch is stuck down?

The dishwasher will not know when to stop filling, which can lead to water pooling on the floor. Cleaning the float usually solves this, but if the switch is damaged, you may need to replace it. See our overflow troubleshooting for more.

Do all dishwashers have a float switch?

Most dishwashers use a float switch or a similar pressure sensor to control water level. The float is common in many brands, including compact and portable models. Check your manual for the exact design.