How to Fix LG Air Conditioner Error E4

What error E4 means

Error E4 on an LG air conditioner, as documented in LG's owner's manual for its portable air conditioner (model LP0814WNR), means the coil sensor temperature is low, so the unit will stop and display E4 to defrost. The manual's remedy is simply that after defrost, the unit will re-start. In other words, on this product E4 is a protective pause rather than a breakdown: the indoor coil has become cold enough to ice over, and the control board stops cooling until the ice has melted. The same manual lists E1 and E2 as thermistor faults that need service and FL as a full water tank, so E4 is the one code in that table that clears on its own. LG's current online error-code guides, which cover split, window and ceiling types, do not list E4, so this page is based on the portable AC manual; if a different LG product shows E4, treat it as unlisted and follow LG's general advice to reset the power and request service if it persists. On a portable AC, E4 that keeps returning usually points to the reasons a coil ices up: choked filters, a blocked exhaust, or running cooling in a cold room.

Why error E4 happens on a LG Air Conditioner

On a LG Air Conditioner, error E4typically resolves to one of three root-cause categories. They’re ordered cheapest-to-verify first — start at the top and only escalate if the first cause is ruled out.

• Mechanical: blockage, obstruction, or worn moving part. A common cause across LG Air Conditioners in India — air filters clog and fan bearings and drain lines collect dust and sludge. Our step-by-step fix below targets this category first because it’s the cheapest to verify and resolvereports.
• Electrical: voltage spike, sensor fault, or PCB anomaly. India’s grid carries more voltage fluctuation than many appliance design tolerances assume, and a routine surge or sag can be enough to throw E4. If you’ve had recent voltage events (lights flickering, AC tripping), start your investigation here. A working stabilizer prevents this entire category.
• Software / configuration: stuck child-lock, demo-mode, or pending firmware reset.Less common but the cheapest fix when it applies — a 60-second factory reset clears it. We list this last because it’s rarely the actual cause, but check it before disassembling anything.

Safety first

Step-by-step fix

1. 1

   Step 1

   Let the defrost finish

   Do not switch the unit off at the wall. LG's manual says the unit stops and displays E4 to defrost and will re-start after defrost. Leave it powered and wait; the fan may keep running while the coil warms up. Once the ice has melted, the display clears and cooling resumes on its own.

   Pro tip: Note how long the pause lasts and how often it happens; a single E4 on a humid evening is normal, one every half hour is not.

2. 2

   Step 2

   Clean the air filter

   Switch the unit off and unplug it. Remove the filter from the back or side of the portable unit, wash it under the tap, let it dry and refit. A dust-choked filter starves the coil of warm room air, which is the most common reason a coil gets cold enough to ice and trip E4 repeatedly.

   Caution: Fit the filter back before running the unit; running without it clogs the coil itself.

3. 3

   Step 3

   Check the exhaust hose and the window kit

   Make sure the exhaust hose is as short and straight as possible, not kinked or crushed behind furniture, and that its outlet through the window kit is not blocked. A restricted exhaust makes the unit run hot and cold in the wrong places and can push the coil into icing.

   Pro tip: Keep the hose length to what the kit provides; extending it with extra tubing is a frequent cause of poor performance.

4. 4

   Step 4

   Raise the set temperature in a cold room

   If the room is already cool, for instance on a monsoon night or early morning, running Cool mode at the lowest setting drives the coil below freezing. Set 24 °C to 26 °C or use Fan or Dry mode. A coil sensor reading low is exactly what LG's manual says triggers E4.

   Pro tip: Portable units work best with doors and windows closed and the unit placed with clear space around its intake.

5. 5

   Step 5

   Empty the water tank

   While the unit is off, check and empty the internal water collection tank if your model has one, following the Care and Cleaning section of the manual. A full tank shows FL rather than E4, but on humid days a unit that is defrosting repeatedly also collects more condensate than usual.

   Caution: Place the unit on a level floor; tilting it affects both drainage and coil behaviour.

6. 6

   Step 6

   Contact LG service if E4 keeps returning

   If the unit trips E4 again and again even with clean filters, a clear exhaust and a sensible set temperature, the coil sensor itself or the refrigerant charge may be at fault. Unplug the unit and contact your authorised LG service centre with the model number and a description of how often E4 appears.

   Caution: Do not open the casing to reach the coil or sensor; the unit contains mains wiring and a sealed refrigerant circuit.

Fixed it? Protect it next time. See an extended warranty plan for your Air Conditioner →

Common mistakes LG Air Conditioner owners make with error E4

These six anti-patterns turn a routine 30-minute fix into a costly repair or warranty void. Read before starting.

• Forcing a stuck door, lid, or panel. Prising open a LG Air Conditioner housing while it is in a fault state. Forcing it usually breaks the latch or sensor — turning a small part replacement into a full service call. If the door won’t open, run the safety-disconnect step first, then try again.
• Repeated unplug-and-replug as a “reset” ritual. Cycling power three or four times without diagnosing the underlying cause stresses the PCB and can convert a soft fault into a permanent firmware-corruption code. Reset once, observe whether the error returns immediately, then move to actual diagnosis if it does.
• Pouring water (or any liquid) into electronics-adjacent areas to flush a blockage.Even a small amount near the PCB or main wiring harness can cause permanent damage that voids warranty. The unit’s drainage paths exist for a reason; if a blockage isn’t cleared by the manual procedure, it isn’t getting cleared by improvisation either.
• Skipping the safety-disconnect step.“I’ll just check quickly” is the most expensive sentence in appliance repair. Working live on a 230V circuit (especially with a hot or wet appliance) carries real shock risk and instantly voids any warranty claim. Disconnect, wait two minutes for capacitor drain, then proceed.
• Buying counterfeit replacement parts on Amazon.in. Red flags: price below 60% of LG authorised price, generic packaging without a model-compatibility list, seller name that doesn’t match a known LG parts distributor, listings dated within the last 30 days with no reviews. Counterfeit parts often work for 2-3 weeks then fail with a different error, costing you double.
• Calling an “independent” technician for a warranty-covered unit. Indian appliances under LG warranty must be serviced by authorised technicians or the warranty voids permanently. Even if the warranty is expired, third-party local technicians often replace working parts to inflate the bill — verify each part swap by asking to see the failure on the old part before they install the new one.

Preventing future E4 on your LG Air Conditioner

The fix above resolves the current instance. These five maintenance habits prevent it from coming back, specific to LG Air Conditioners in Indian operating conditions (hard water, voltage variability, monsoon humidity).

• Monthly: wash the air filters and clear the drain line. Hard-water deposits and everyday debris are a frequent cause of recurring E4 in India, and a few minutes each month is the cheapest way to avoid a repeat.
• Quarterly: descale water-touching components. Use food-grade citric acid or a LG approved descaler for hard-water regions (Bangalore, Hyderabad, large parts of Maharashtra and Tamil Nadu). Skipping this in a hard-water zone shortens the life of the heating and water-touching parts.
• Run the unit through a working stabilizer. A mainline stabilizer sized for Air Conditioners is the cheapest protection against voltage-induced E4 occurrences. The MCB on your distribution board is not a substitute — it trips on overload, not on under-voltage or surge.
• Decide AMC vs DIY honestly. Compare the LGAMC quote against what you have actually spent on service. If your unit is >5 years old and you’ve had two service calls in the last 18 months, an AMC usually pays for itself. Younger units with no service history: DIY plus stabilizer is cheaper.
• Watch monthly for early-warning signs. Unusual noise during a specific cycle phase, water spotting, mild burning smell — any of these means a service call within a week, not a wait-and-see month. Catching E4-precursor symptoms early turns a major repair into a routine maintenance visit.

If error E4 returns within 30 days of completing the fix above, escalate directly to LGauthorised service — repeat patterns within a month indicate a deeper fault (worn bearing, failing PCB, leak that wasn’t fully identified) that surface-level repair won’t resolve. Document the dates and circumstances of each occurrence; the service centre will use this to prioritize root-cause investigation.