Troubleshooting guide
Dishwasher Not Filling With Water? Causes and Fixes
- ✓ $79 diagnostic, credited to the repair
- ✓ 45-day parts & labor warranty
- ✓ Same-day & next-day visits
- ✓ 6+ years repair experience
Quick answer
If your dishwasher isn't filling, first make sure the water supply valve under the sink is fully open, then check that the float in the tub moves freely. If you hear a hum but no water flows, the water inlet valve has usually failed or its screen is clogged. A faulty door switch or control board can also stop the fill.
A dishwasher that doesn't fill will run through its cycle dry, or stop and show an error. Either way, nothing gets clean. The good news is the fill system is simple: a supply valve, a hose, an electric inlet valve, and a float that tells the dishwasher when to stop.
Give the dishwasher a minute before deciding it isn't filling. Many models run the drain pump first to clear old water, so you may not hear water coming in until 30 to 90 seconds into the cycle.
Causes, from most to least likely
1.Water supply valve closed or partly closed
The small shutoff valve under the sink feeds the dishwasher. It gets turned off during plumbing work, faucet replacements and rental make-ready, and nobody turns it back on. A valve that's only partly open causes a slow, weak fill.
- Check it yourself
- Look under the sink for the valve on the line heading to the dishwasher. Turn it fully counterclockwise. Older multi-turn valves can stick — if it won't turn, don't force it.
- The fix
- A seized or leaking shutoff valve is a plumbing repair. The dishwasher itself may be fine.
2.Float stuck in the up position
A plastic float, usually in a front corner of the tub floor, rises as water fills. When it reaches the top, a switch underneath tells the dishwasher to stop filling. If debris or grease holds the float up, the dishwasher thinks it's already full.
- Check it yourself
- Find the float (a small dome or cylinder in the tub floor). Lift it gently and let it drop. It should move freely and click. Clean around it with warm soapy water.
- The fix
- If the float moves but the switch underneath has failed, the float switch is replaced.
3.Clogged or failed water inlet valve
The inlet valve is an electric valve behind the kick panel. Its inlet screen catches sediment and can clog, especially after work on the water main. The solenoid coil that opens the valve can also burn out. A failed solenoid often produces a hum with no water.
- Check it yourself
- Listen at the bottom of the dishwasher at the start of a cycle. A hum or buzz with no water sound points to the valve. With the breaker off, remove the kick panel and look for leaks or mineral crust around the valve.
- The fix · typical $150 – $250
- We test the solenoid and replace the valve if it's open or weak. It's a common part and a quick repair.
4.Kinked supply line or low water pressure
The supply line can kink when the dishwasher is pushed back in. Low household water pressure, or a boil-water notice where lines were just flushed, can also slow the fill.
- Check it yourself
- Check that the kitchen faucet has normal pressure. Follow the supply line under the sink for kinks.
- The fix
- A kinked or damaged line is replaced. Sediment that came through after a water-line repair often clogs the inlet screen, which is cleared or the valve replaced.
5.Door latch or door switch
The dishwasher won't open the inlet valve unless it knows the door is latched. A failing door switch can let the control light up but block the fill.
- Check it yourself
- Close the door firmly and listen for a click. If the door feels loose or the latch is cracked, this is likely.
- The fix · typical $150 – $260
- A worn latch or door switch is replaced.
6.Control board not powering the valve
The control board sends power to the inlet valve. A failed relay or a surge-damaged board can leave a good valve with no power.
- Check it yourself
- Not a homeowner test. Note any error code and look it up in your manual.
- The fix · typical $260 – $480
- We check for voltage at the valve during the fill. If there's none and the wiring is good, the board is the problem.
When to call a technician
Call us if the supply valve is fully open, the float moves freely and the dishwasher still won't fill, or if you hear humming with no water. We test the inlet valve, float switch and door switch before replacing anything. You'll get a written price first, and the $79 diagnostic is credited to the repair.
45-day parts & labor warranty
Every repair carries a 45-day warranty on the parts we install and on our labor.
What the warranty covers →Common questions
How much water should a dishwasher fill with?
+
Less than most people expect. Many modern dishwashers use only a few gallons for a whole cycle, and the water may only cover the sump area at the bottom of the tub. That's normal.
Why does my dishwasher hum but not fill?
+
A hum with no water flow usually means the water inlet valve's solenoid is energized but the valve isn't opening, or its screen is clogged. Make sure the supply valve is open first.
My dishwasher stopped filling after a plumber worked on my sink. Why?
+
The dishwasher supply valve may have been left closed, or sediment knocked loose during the work clogged the inlet valve screen. Check the valve under the sink first.
Can I run my dishwasher with low water?
+
It will run, but dishes won't get clean, and the wash pump can wear faster running short of water. Fix the fill problem first.
How much does a dishwasher inlet valve cost to replace?
+
Typically $150–$250 total, including the part, labor and the $79 diagnostic credit. It usually takes under an hour.
Related guides
Last reviewed 2026-10-07 by Mako Appliance Repair, Clearwater FL.
Rather not DIY it? We can usually come today.
$79 diagnostic credited to your repair · 45-day parts & labor warranty · Open 7 days · 7:30am–8:30pm