The OF error code means your LG washer has detected too much water in the drum — an overflow condition. The most common cause is a faulty water inlet valve that doesn't fully close, allowing water to seep in even when the machine is idle. You should unplug the washer immediately to stop water flow. While one DIY check (inspecting the water level pressure hose) is worth trying first, this code frequently requires a replacement water inlet valve or pressure switch — a job best handled by a technician.
What the OF Code Means
Your LG washer continuously monitors the water level inside the drum using a pressure switch (also called a water level sensor). When the water exceeds the maximum safe threshold — or continues to rise when it shouldn't — the machine stops the cycle, triggers the drain pump, and displays OF (overflow fault).
Unlike a filling error, an overflow means water is actively getting where it shouldn't be. This can be caused by a valve that won't close properly, a pressure switch that has lost its ability to sense the water level accurately, or a blocked pressure hose that is feeding the switch false readings.
Unplug the washer as soon as you see OF. If the water inlet valve is stuck open, the machine will continue to fill even with the power on. After unplugging, check whether water is still trickling into the drum — if it is, the inlet valve is the likely culprit.
Common Causes — Most Likely First
How to Fix the OF Error — Step by Step
Unplug the washer immediately
Pull the power cord from the wall outlet (or switch off the circuit breaker) as soon as you see the OF code. This is the most important first step — if the water inlet valve is stuck open, unplugging the machine stops the electrical signal that can hold it open.
Close the water supply valves
Turn both the hot and cold supply valves behind the washer fully clockwise to close them. This stops any ongoing water flow to the machine while you investigate, regardless of whether the inlet valve is stuck.
Run a drain-only cycle to remove excess water
Plug the washer back in and select the Spin/Drain cycle (no wash, no fill). Let it complete to remove the standing water from the drum. This prevents any risk of overflow onto the floor during your inspection and clears the error state.
Check detergent type and quantity
Open the detergent drawer and verify you're using HE (High Efficiency) detergent. Standard detergent produces far too many suds in an LG front-load or top-load HE machine. If you used the wrong type, run an empty rinse cycle two or three times to clear the suds.
Inspect the pressure switch hose
Access the back panel of the washer (two to four screws). Locate the small rubber or plastic hose running from the bottom of the drum up to the pressure switch — a small round component, usually mounted near the top of the cabinet. Check that the hose is firmly attached at both ends, isn't kinked, and has no visible blockages. Blow gently through it to confirm it's clear. Reattach any loose connection.
Restore water supply and run a test cycle
Reopen the supply valves, close the back panel, and run a short cotton or quick-wash cycle. Stay nearby and watch the first few minutes. If the machine fills to a normal level and the cycle runs without displaying OF, the issue is resolved.
If the code returns — the inlet valve or pressure switch needs replacement
A recurring OF code after clearing suds and verifying the pressure hose almost always means the water inlet valve is mechanically stuck open, or the pressure switch has failed and requires replacement. Both are internal parts that require disassembly and diagnostic confirmation before replacing — call a technician at this point.
When to Call a Technician
The OF code frequently requires a part replacement. Book a professional repair if:
- Water continues to enter the drum after the washer is unplugged
- The code returns after you've verified the pressure hose and switched to HE detergent
- The drum remains full of water and won't drain even on a Spin/Drain cycle
- You can hear the inlet valve clicking but water flow doesn't stop
- There are signs of water leaking onto the floor around the washer
Repair Cost Expectations
If You Fix It Yourself
Professional Repair
Still Seeing OF? We'll Fix Your LG Washer.
Same-day appointments across Boston. Certified LG technicians, common parts stocked on the truck, and a 90-day warranty on every repair.
Frequently Asked Questions
Is the LG OF code the same as the OE code?
No — these are opposite problems. OF (overflow) means too much water is getting into the drum. OE (outlet error) means the washer can't drain the water out. Both can leave the drum full of water, but the cause and repair are different. If you're unsure which code you're seeing, check the display carefully: OF has a rounded "F", while OE ends in "E".
Can too much detergent really trigger the OF code?
Yes, and it's more common than people expect. Excess suds create a foam column that rises above the actual water level. The pressure switch — which measures water level by air pressure in a small chamber — can misread this foamy column as a true overflow and trigger the OF fault. Switching to an HE-rated detergent and using no more than the recommended amount (usually one to two tablespoons) often clears the code permanently.
My LG washer shows OF but the drum looks almost empty — why?
This usually points to the pressure switch or its hose rather than an actual overflow. The pressure switch may be faulty and reporting a false "full" reading even when the drum is nearly empty, or the hose connecting it to the drum may be blocked with detergent residue. Inspect and clear the pressure hose first. If the code persists, the switch itself likely needs replacement.
How much does it cost to fix an LG washer OF error?
If switching to HE detergent or reseating the pressure hose resolves the issue, the cost is zero. If a part needs replacing, a water inlet valve typically costs $25–$50 for the part alone; a pressure switch runs $20–$40. Professional repair in the Boston area — including diagnosis, parts, and labor — generally runs $150–$270 with a 90-day warranty.