Find and clean the second filter
Almost every one of these machines has a coarse filter in the door and a second, finer stage behind a flap at the base, often protecting a heat exchanger. The door filter gets cleaned every load; the lower one frequently never does. A blocked heat exchanger makes the machine run hot, dry poorly and pack fibre against a warm surface, which is exactly the condition to avoid.
What you find
- Drying times increasing steadily over months — The classic sign of a blocked lower filter or exchanger.
- A thick mat of lint behind the lower flap — Direct evidence, and often the first time an owner has looked.
- The machine and the room get unusually warm during a cycle — Heat that is not being handled as designed.
- A musty or hot smell from the machine — Damp lint on a warm surface, and it is a reason to act rather than ignore.
- The water tank fills more slowly than it used to — Less moisture being condensed, which accompanies restricted airflow.
- NEAR MISS: a warm cabinet on a heat-pump machine — Expected; these run at lower temperatures but for longer.
Ranked for a condenser machine
- A blocked heat exchanger or lower filter — First. It is the stage owners do not know about, and it accumulates a dense mat of fibre that restricts everything downstream.
- A door filter cleaned but never washed — Second. Softener film blocks air invisibly and lets more fibre through to the lower stage.
- A full or unemptied condensate tank — Third. It stops the machine rather than causing a hazard, but it accompanies neglect of the rest.
- A degraded supply connection — Last, and it is the same connection question as on any other dryer.
Door filter, lower stage, then the supply
- Clean the door filter and wash the mesh under water — The routine item, and washing catches the invisible film.
- Open the lower flap and inspect the second stage — The top cause, and frequently a surprise the first time.
- Clean the exchanger fins as the manual describes — It restores airflow and lowers the running temperature.
- Check the plug and socket for warmth — The connection question applies to every dryer regardless of type.
Owner steps
- Take out the door filter and run water onto the mesh — If water pools rather than passing straight through, softener film is blocking air as well.
Tools: warm waterAbout 10 min
- Open the flap at the base and remove the lower filter stage — This is the stage most owners have never opened, and it is where the fibre collects.
Tools: glovesAbout 15 min
- Clean the heat exchanger fins with a soft brush or as the manual directs — Do not use anything sharp; the fins are thin and bend easily.
Tools: brushAbout 20 min
- Empty the condensate tank and check the drain route if one is fitted — A full tank stops the machine, and an unused tank often means an unchecked drain.
About 10 min
- STOP before the cabinet or any panel beyond the service flaps is opened — Mains voltage and a sealed refrigerant system sit inside a heat-pump machine.
The rules for this machine type
Safety
Unplug the appliance or switch off its breaker before removing any panel, and never run the machine with a filter missing: it is the only thing keeping fibre out of the exchanger. Do not touch the sealed refrigerant system inside a heat-pump machine. Do not run a dryer unattended overnight, and stop at once for any scorched smell.
When to call
Call for a service clean if drying times have been growing despite a clean door filter, since the exchanger may need attention beyond the service flap. Call immediately for any scorched smell or a breaker that trips. Say the machine is a condenser or heat-pump model: the maintenance items and the parts involved are different from a vented one.
Nearest pages of this class
Scope of this page
Written for the LG dryer class rather than one model line, with condenser and heat-pump machines in mind because their maintenance differs. Filter stages and exchanger designs differ by family and belong on the page for your specific machine.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
