Whirlpool Washer Error Code F40 — What It Means & How to Fix It

What Does This Error Mean?

Error code F40 on a Whirlpool washer means the water inlet valve has failed to operate correctly. The inlet valve controls the flow of hot and cold water into the drum. When the control board detects the valve is not responding as expected, it sets F40 and stops the fill cycle. You will notice the washer is not filling with water or is filling too slowly. This is most often a failed inlet valve or a water supply issue.

Affected Models

Whirlpool Front-Load Washers
Whirlpool Duet series
Whirlpool WFW series
Whirlpool Top-Load Washers

Common Causes

A failed water inlet valve solenoid that no longer opens when commanded
Low household water pressure not meeting the valve's minimum operating pressure
Kinked or blocked supply hoses behind the washer
Clogged inlet valve mesh screens blocking water flow
A faulty main control board not sending the correct voltage signal to the valve

How to Fix It

Check both water supply hoses at the back of the washer. Make sure the hot and cold shutoff valves are fully open. Check that neither hose is kinked. A hose that is bent tightly behind the washer can restrict water flow enough to cause F40.

Pull the washer slightly away from the wall to inspect the hoses and valves — there should be a gentle curve, not a sharp kink.
Check your home water pressure. Whirlpool washers require a minimum of 20 PSI and maximum of 120 PSI at the inlet. Very low pressure can cause the inlet valve to not open properly. You can buy an inexpensive water pressure gauge at a hardware store and attach it to an outdoor spigot to test.

If your home pressure is below 20 PSI, contact a plumber. Low pressure affects all water appliances.
Clean the inlet valve mesh screens. Turn off the water supply valves, disconnect both supply hoses from the back of the washer, and look inside the valve ports. You will see small mesh screens — remove them carefully with needle-nose pliers and rinse them clean under running water.

Sediment and mineral deposits clog these screens over time, especially in areas with hard water.
Test the inlet valve solenoid coils with a multimeter. A working solenoid reads 200-500 ohms. An open reading (infinity) means the solenoid has burned out and the full inlet valve assembly must be replaced.

Inlet valves have separate solenoids for hot and cold water — test each one.
Replace the inlet valve if it fails the resistance test or if cleaning the screens did not help. Use your full washer model number to find the correct replacement valve. Turn off the water supply completely before starting the replacement.

Have a towel ready — residual water will drain from the hoses when disconnected.

When to Call a Professional

If water pressure and supply hoses are fine and cleaning the screens does not help, the inlet valve needs to be tested and likely replaced. Inlet valves cost $40-$80 and require the back panel to be removed for access. A technician can replace the valve in about an hour for $120-$220 total.

Frequently Asked Questions

Why would the inlet valve suddenly fail?

Inlet valve solenoids have a limited lifespan — typically 10-15 years of normal use. They can also fail prematurely due to water hammer (pressure shocks in the pipes), mineral scale buildup, or power surges. Valves in areas with hard water tend to fail sooner because mineral deposits damage the solenoid and seal over time.

Can I clean a clogged inlet valve or must I replace it?

The mesh screens inside the valve ports can be cleaned and reused. However, if the solenoid itself has failed — meaning the coil has burned out — the entire valve must be replaced. You cannot repair a burned solenoid coil at home. Clean the screens first, then test the solenoids with a multimeter to determine if replacement is needed.

How much does it cost to fix F40?

Cleaning inlet screens: free. A replacement inlet valve: $40-$80 for parts. A technician service call for valve replacement: $120-$220 including parts. If the main control board is at fault: add $150-$400 for board replacement.