Bosch Dishwasher Check Water Light – Meaning, Causes & Fix

BoschDishwasherUpdated 2026-08-07

The "Check Water" light on a Bosch dishwasher illuminates when the appliance's control board detects a problem with water supply, typically that the dishwasher is not receiving enough water, or no water at all, during its fill cycle within the expected time window. This indicator is common across Bosch's Ascenta, 300, 500, and 800 series dishwashers and is one of the most frequent reasons a cycle stalls or fails to start properly. This guide explains the common causes behind this light and the full troubleshooting sequence. For related dishwasher indicators, see our Bosch Dishwasher Tap Symbol Flashing guide and our Bosch Dishwasher Brush Light Flashing guide.

Quick Answer

What it means

The dishwasher did not detect sufficient water intake during its fill cycle, commonly due to a closed or kinked supply valve, a clogged inlet filter, or a faulty water inlet valve.

Severity

Moderate

Can you fix it yourself?

Yes — checking the water supply valve and inlet filter is straightforward and requires no special tools.

Call a technician when

Contact a certified technician if the water supply is confirmed on and unobstructed but the light persists, as this may indicate a faulty water inlet valve or float switch.

What Does Check Water Light Mean?

Bosch dishwashers monitor water intake during the fill portion of each cycle using a flow meter or float switch system. The "Check Water" light activates when the appliance either doesn't detect water flow starting within a set time, or the flow stops before the expected fill level is reached.

Common underlying causes include:

1. Water supply valve not fully open: The shutoff valve under the sink or behind the dishwasher may be partially or fully closed. 2. Kinked or damaged water supply line: The flexible hose delivering water to the dishwasher can become kinked, especially after the unit is moved for cleaning. 3. Clogged inlet filter screen: A small mesh filter where the water line connects to the dishwasher can become clogged with sediment over time. 4. Faulty water inlet valve: The electronically controlled valve that opens to allow water in can fail electrically or become stuck. 5. Low household water pressure: Insufficient pressure from the home's plumbing can prevent the dishwasher from filling within its expected time window.

This type of water-supply detection fault is similarly diagnosed to the Bosch Dishwasher Tap Symbol Flashing issue, both stemming from the appliance's fill-monitoring system detecting an abnormal water flow condition.

What Causes This Error?

Water supply shutoff valve partially or fully closed
Kinked, pinched, or damaged water supply hose
Clogged inlet filter screen at the water connection point
Faulty or stuck water inlet valve preventing proper water flow
Low household water pressure insufficient for the fill cycle's time window
Air lock in the water supply line, especially after plumbing work
Float switch stuck or malfunctioning, falsely indicating insufficient water
Recently installed or serviced dishwasher with an improperly connected water line

How to Fix Check Water Light

1
Verify the water supply shutoff valve is fully open. Locate the valve, typically under the kitchen sink or behind the dishwasher's lower kick panel, and confirm it's turned to the fully open position. This valve is often accidentally left partially closed after other under-sink plumbing work.
2
Inspect the water supply hose for kinks or damage. Carefully pull the dishwasher out (with power and water disconnected first) to check the flexible supply line running from the shutoff valve to the unit for any kinks, tight bends, or visible damage.
3
Clean the inlet filter screen. With the water supply off, disconnect the water line at the dishwasher's inlet valve connection and check for a small mesh filter screen, which can become clogged with mineral deposits or debris. Rinse it clean under running water and reinstall.
4
Check household water pressure. Run a faucet elsewhere in the kitchen to confirm normal water pressure and flow. If pressure seems noticeably weak throughout the home, this may be a plumbing issue affecting the dishwasher's ability to fill in time, separate from the appliance itself.
5
Power cycle the dishwasher and run a test cycle. Turn off the dishwasher at the circuit breaker for 5 minutes, then restore power and start a normal cycle to observe whether the Check Water light returns during the fill phase.
6
Have a technician test the water inlet valve if the light persists. If supply, hose, and filter are all confirmed clear and functioning, a certified appliance technician can test the water inlet valve's solenoid coil for proper electrical resistance and replace it if it has failed.

When to Call a Professional

If the water supply valve, hose, and inlet filter are all confirmed clear but the Check Water light continues to appear, contact a certified Bosch appliance technician. A faulty water inlet valve typically costs $80-$180 including parts and labor to replace and requires basic electrical and plumbing disconnection that's straightforward for a professional but involves working with both water and electrical connections.

Can You Still Use the Device?

A Bosch dishwasher displaying the Check Water light will typically pause or fail to complete its cycle, meaning dishes will not be properly washed until the underlying water supply issue is resolved. Continuing to run cycles without addressing this light wastes time and detergent without achieving a clean wash, so address the water supply issue before attempting further cycles.

Official Resources

Disclaimer: This article is for informational purposes only and does not constitute professional repair advice. CodeExplain is not affiliated with Bosch or any other brand mentioned. Always consult a qualified technician for complex repairs.