A washing machine that fills slowly or throws a water supply fault has three likely causes and they are checked in a specific order, cheapest first. There is a screen in the hose coupling, sometimes a second screen at the machine's own inlet, and behind both an electrically operated valve that opens to admit water.
Start at the tap end
Close the tap and unscrew the inlet hose from it. A fine mesh screen sits recessed in the coupling, usually removable with pliers by a small tab. Rinse it, brush anything stubborn away, and soak it in a descaler or vinegar if it is furred with scale rather than dirty with grit. Check the rubber washer at the same time and replace it if it is hardened or distorted. Seat the screen fully on refitting, since one left proud tears as the hose is tightened.
Then the machine end
Many machines have a second screen where the hose meets the appliance, in front of the inlet valve, and it is the one people forget because the tap end screen gets all the attention. Close the tap, unscrew the hose at the machine and look into the port. Some are integral to the valve body and cannot be removed, in which case clean in place carefully without pushing debris further in. On two hose machines check both, since one side filling far slower than the other localizes the fault immediately.
Testing the valve itself
If both screens are clear and the fill is still slow, the solenoid valve is the candidate. It can jam partly open or partly closed with grit, or its coil can fail. With power off, check the wiring and connections, then measure the coil for continuity if you are equipped to. A valve that hums but passes little water is usually mechanically obstructed, and one that does nothing at all with power present is usually electrical. Valves are inexpensive parts and are a common replacement.
Stopping it happening again
Repeated blockages mean the supply is carrying sediment continuously, and clearing screens is treating the symptom. An inline cartridge filter on the machine's feed catches the material before it reaches either screen, and it suits well supplies, older galvanized pipework and properties where mains work regularly stirs the line. Fit it where it can be serviced without moving the machine and support the housing on a bracket. Our whole house filter guide covers treating the property rather than the appliance.
Questions people ask about washing machine inlet filter
Where are the screens on a washing machine?
One recessed in the inlet hose coupling at the tap end, and often a second at the machine's own inlet port in front of the valve.
The screens are clear but it still fills slowly, what now?
The inlet solenoid valve. A valve that hums but passes little water is obstructed, and one doing nothing with power present is electrical.
The screen is furred rather than dirty, what is that?
Scale from hard water. Soak it in a descaler or vinegar until clear, then rinse and refit it fully seated with a sound washer.
How do I stop it blocking repeatedly?
Fit an inline cartridge filter on the machine's feed so sediment is caught before it reaches either screen or the valve.