FF
LG Washing Machine
Severity: ModerateWhat Does This Error Mean?
The FF error means your LG washer is detecting a frozen water supply line. The machine tried to fill with water but could not get enough — likely because a pipe is frozen. This typically happens in cold months when the washer is in a garage or cold utility room. You need to thaw the supply line before the washer can run.
Affected Models
- WM3900HWA
- WM4000HWA
- WM3700HWA
- WM1388HW
- Most LG front-load and top-load washers in cold climates
Common Causes
- Water inlet hose or supply pipe frozen due to very cold ambient temperatures
- Washer located in an unheated garage, basement, or utility room in winter
- Cold air draft near the water supply pipes — such as an exterior wall with poor insulation
- Water left sitting in the inlet hose after a previous cycle froze overnight
- Very low indoor temperature — below 32°F in the laundry area
How to Fix It
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Do not try to force the washer to run — it will not fill.
Running the washer without water can damage the drum seals and other components. Wait until the pipes are thawed.
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Warm up the laundry room to above 50°F (10°C).
Use a portable space heater to raise the room temperature. Focus heat near the water supply pipes behind the washer.
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Wrap the cold water supply pipe with an electric pipe heat tape if accessible.
This is available at hardware stores. Do not use open flame or a heat gun near pipes or the machine.
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Wait 30–60 minutes for the supply pipes to fully thaw.
Turn on a nearby cold water faucet to check if normal water pressure has been restored before trying the washer.
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Once water flows freely, restart the washer on a normal cycle.
The FF error should clear once the machine successfully fills with water. If FF persists after thawing, check the inlet valve for freeze damage.
When to Call a Professional
The FF error itself is not a mechanical fault — it is an environmental problem. If you thaw the pipes and FF keeps returning in normal temperatures, the water inlet valve may have been damaged by the freeze. A cracked inlet valve needs professional replacement. Contact LG support at 1-800-243-0000 or a local plumber to inspect the supply line.
Frequently Asked Questions
Is it safe to use a hair dryer to thaw frozen pipes?
A hair dryer can be used carefully on supply pipes only — not on the washer itself. Keep the dryer on its lowest heat setting and keep it moving. Never apply heat directly to plastic fittings, rubber hoses, or electrical components. A space heater warming the room is safer and more effective.
How do I prevent the FF error from happening again?
Insulate your water supply pipes with foam pipe insulation — it is cheap and easy to install. If the washer is in a garage, consider installing a small space heater set to a minimum of 50°F in winter. After the last wash of the day, turn off the water supply taps. This prevents water from sitting in the hose where it can freeze overnight.
Can a frozen pipe cause permanent damage to my LG washer?
A frozen pipe alone usually does not damage the washer. However, if the pipe or inlet hose bursts from the freeze, water damage can occur. Also, if water inside the inlet valve freezes and expands, it can crack the valve. Always check the inlet hose and valve for cracks after a freeze event before running the machine.