Samsung Washer 4C Error? 6 Fixes for the Water Supply Code

The Samsung washer beeps, the display shows 4C and the drum sits there dry with your clothes in it. 4C (or 4E on models before 2016) is the water supply code: the machine opened its valve, waited, and not enough water arrived. Almost every cause sits between the wall and the back of the machine, which means you can fix nearly all of them without a tool.

First question: does the machine take a little water and then stop, or none at all? A trickle points at a clogged screen or low pressure. None at all points at a closed tap, a frozen or kinked hose, or the valve inside. Both start at the taps.

Start With These 30-Second Checks

1. 1Look at both taps behind the machine. Each lever should be fully in line with the pipe (open), not across it.
2. 2Pull the machine forward a hand's width and look at the hoses. A hose crushed against the wall or trapped under a foot cannot pass water.
3. 3In winter, feel the hoses and the wall pipe. A frozen hose is stiff and cold; a garage or outbuilding washer gets 4C on the first cold morning.
4. 4Run the cold tap at the sink nearest the machine. A weak flow there means the house pressure is the problem, not the washer.

1. Open the Taps All the Way and Check the Hoses

A tap that is a quarter open lets the machine trickle-fill and time out. Taps get knocked when the machine is pushed back, and the lever type can look open at a glance while it is half shut.

1. 1Turn each tap fully open, then a quarter back so it does not seize.
2. 2Straighten any kink in the hoses and re-route them so the machine can sit against the wall without pinching them.
3. 3Push the hose ends firmly onto their taps and check the connections by hand; a loose nut lets air in and slows the fill.
4. 4If a hose is bulging, cracked or over five years old, close both taps first, then replace the pair; braided stainless hoses cost $15 to $30 and will not burst.

2. Clean the Inlet Mesh Filters

Where each hose screws into the back of the washer there is a small dome of fine mesh. It catches grit and limescale from the pipes and it is the number one cause of a 4C that appears gradually over months.

1. 1Close both taps and unplug the washer.
2. 2Unscrew the hoses at the machine end over a towel; about a cup of water comes out.
3. 3Look into each inlet on the machine. Pull the mesh dome out with needle-nose pliers, gripping the rim, not the mesh.
4. 4Rinse the mesh under the tap and scrub it with an old toothbrush. If it is white with limescale, soak it in vinegar for 20 minutes.
5. 5Push the screens back in dome-outwards, refit the hoses hand-tight plus a quarter turn, open the taps, check for drips, plug in and start a rinse cycle.

3. Low Water Pressure or a Half-Closed Stop Valve

Samsung machines expect at least about 20 psi. Below that the fill takes longer than the timer allows. Pressure problems come and go, which is why 4C can appear only on some days.

1. 1Time the cold tap at the nearest sink filling a 1 litre jug. Under about 6 seconds is fine; over 10 seconds points at low pressure or a partly closed valve.
2. 2Trace the pipe from the washer taps back and look for an isolation valve or stopcock that is not fully open.
3. 3If the whole house is slow, check the main stopcock and ask neighbours; a pressure problem in the street is the water company's job.
4. 4As a workaround, run the wash when no one is showering and no outside tap is on.

4. Hot and Cold Hoses Swapped (4C2)

If the display says 4C2 rather than 4C, the machine is measuring hot water at its cold inlet. The hoses are on the wrong taps, or the hot tap is feeding a machine that only has a cold connection.

1. 1Close both taps and unplug the washer before you swap anything.
2. 2Follow each hose from the tap to the machine; the inlets on the back are marked with a red and a blue ring or the letters H and C.
3. 3Swap the hoses so hot goes to hot and cold to cold. On a cold-fill-only machine, connect the single hose to the cold tap and cap the hot tap.
4. 4Open the taps, plug in and run a rinse cycle. 4C2 should not return.

5. The Water Inlet Valve Inside the Machine

If the taps are open, the screens are clean and the pressure is fine, the electrically operated valve inside the washer may not be opening. You will usually hear a click when the machine tries to fill; a dead valve is silent. This is a $30 to $60 part and a moderate job.

1. 1Unplug the washer and close both taps before you open the back.
2. 2Remove the top or rear panel (a few screws) to reach the valve block where the hoses come in.
3. 3Unplug the two-pin connectors from each solenoid and test the coil with a multimeter on ohms. A reading around 1 to 2 kilo-ohms is normal; open circuit means the coil is dead.
4. 4Replace the valve block as one unit. Note which hose goes where with a photo before you pull the internal hoses off, and fit the new clamps snugly.
5. 5Reassemble, open the taps, plug in and run a rinse cycle with the top off, watching the valve for drips.

6. When to Call a Pro

Book a technician when the valve tests fine and the machine still will not fill, when the water level sensor or pressure switch is suspected, or when you see 4C together with other codes. If the machine fills but then shows a drain code instead, that is a different fault; see washer not draining.

1. 1The valve clicks, water pressure is good and the drum still stays dry: the pressure sensor or its hose is likely blocked, which needs the front panel off.
2. 24C appears mid-cycle rather than at the start: an intermittent valve or a board fault, which is guesswork without the service manual.
3. 3Any sign of water inside the electronics area at the top: unplug it and do not run it again.
4. 4A machine over 10 years old needing a valve and a pump: put the money towards a replacement.