How to Troubleshoot an LG Dryer That Won't Heat

LGLG DryerModerate⏱ 2 - 3 hours

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If an LG dryer runs but doesn't heat, the problem is often incoming power, the heater assembly, a thermal cutoff or fuse, the thermostat, or the thermistor. This guide shows how to open a common LG dryer design, test the heating components with a multimeter, replace the heater canister assembly if needed, and reassemble the dryer.

🧰 Tools

Phillips Screwdriver
Multimeter
Needle Nose Pliers
Vacuum Cleaner

⚙️ Parts

Heater canister assembly
Thermistor
blower housing fuse
thermal cutoff sensor
thermostat
Power cord
Terminal block

ШагиSteps

Check incoming voltage at the terminal block

Use a Phillips screwdriver to remove the rear plate that covers the power cord terminal block.
Set a multimeter to AC voltage.
Measure voltage between the middle and left terminal screws, the middle and right terminal screws, and the left and right terminal screws.
Look for about 120 V AC between middle-left and middle-right, and about 240 V AC between left-right.
Caution: You’re measuring live voltage at the terminal block, so keep the meter probes controlled and don’t touch metal parts.

Inspect the cord and terminal block for damage

Visually inspect the terminal block, the terminal screws, and the power cord where it connects to the terminal block.
Inspect the power cord where it plugs into the wall outlet.
Replace any burnt, singed, or damaged parts you find, including damaged wires, the terminal block, or the power cord.

Reset the breaker and decide whether to call for electrical service

Turn the dryer breaker fully off, and then fully on, to reset it.
A tripped breaker can drop the heating leg connection, and some models may show codes like NP or PF for this kind of power issue.
Call an electrician if you still can’t get correct voltage at the terminal block after resetting the breaker.
Continue with disassembly if the incoming voltage tests correctly.

Remove the top panel and steam tray housing if equipped

Remove the three screws at the bottom of the metal bracket near the top front of the dryer.
Remove the top panel to expose the drum and internal housing.
Some LG models also have two screws behind this bracket that must be removed.
If the dryer has a steam tray, remove the water tray, and pull up the hidden tab at the bottom of the plastic housing to release and remove the tray housing.

Disconnect and remove the control interface

Unplug the wire harnesses that run from the control interface to the main electronic board at the back of the dryer.
Disconnect the three harnesses on this model, with two on the left side and one on the right.
Remove the two Phillips screws from the front of the steam tray area on this model.
Lift the top of the interface panel, and roll it away from the dryer bulkhead.
Some models need extra force to release retention tabs holding the interface to the metal bulkhead.

Disconnect the door switch and light harnesses

Unplug the white door switch harness and the red light harness that were hidden by the interface panel.
Move these wires away from the bulkhead, typically toward the rear of the dryer.

Remove the front door cover

Remove the two screws at the top of the door area.
Remove the four screws inside the door opening, with one in each corner.
Slide the top of the door cover forward, and lift it up off the metal feet at the bottom.
Screw count and locations may vary slightly, so remove all screws securing the cover on your model.

Remove the interface mounting bracket and crossbar screws

Remove the four screws holding the metal plate that supported the interface panel.
Remove the two screws behind the top area, and remove the front-left and front-right screws on this model.
Remove the extra single screw from each crossbar that holds the circuit board area in place on this steam model.
Lift the plate off the dryer.

Move the steam system and control board out of the way

Remove the two screws holding the control board in place.
Remove the ground screw that connects the steam system to the crossbar.
Remove the screws at the back that secure each crossbar to the rear of the dryer.
Detach the rubber hose going to the steam system from the dryer.
Slide the steam system plastic arms toward the rear to release the housing, and remove the steam system assembly.
You can leave wiring attached and flip assemblies out of the work area if there’s enough strain relief.

Remove the front bulkhead

Remove the four Phillips screws, with one in each corner of the bulkhead.
Remove the screw at the very bottom of the blower housing.
Unclip the moisture sensor in the lower-right corner of the dryer.
Lift the bulkhead up to dislodge it from its tabs, and remove it from the drum.
Caution: Removing the bulkhead lets the drum drop down onto the blower housing.

Release the belt and remove the drum

Reach between the drum and blower housing, and find the idler pulley by feel.
Push the idler pulley to release belt tension, and slip the belt off the motor spindle.
Use the belt as a handle to lift and remove the drum from the dryer.
Inspect the drum for visual damage, and vacuum lint from inside the cabinet while it’s open.

Test the heating element for correct resistance and shorts

Use needle-nose pliers to remove at least two of the three wires from the heating element to isolate it for testing.
Set the multimeter to ohms, and test resistance between the element terminals in all three combinations.
Check red-to-blue for about 20 Ω, blue-to-yellow for about 40 Ω, and red-to-yellow for about 20 Ω.
Replace the heater housing assembly if readings are far outside these values.
Test for a grounded heater by touching one meter lead to a terminal and the other lead to the heater canister.
WARNING: Replace the heater assembly immediately if you get continuity to the canister instead of OL, because a grounded element is dangerous and can heat poorly.

Test the thermal cutoff and thermostat

Remove a wire from the thermal cutoff sensor with needle-nose pliers.
Set the multimeter to ohms resistance or continuity, and probe the sensor terminals.
Replace the sensor if the meter reads OL, and treat a reading near 0.00 as good.
Some LG dryers have a reset button on this type of sensor, but most models do not.
Remove the red wire from the rear thermostat, and test it the same way.
Replace the thermostat if it reads OL, and treat a reading near 0.00 as good.

Inspect heater wiring and test the thermistor and blower fuse

Inspect wires at all heater and sensor spade connectors for heat damage, burn marks, or scorch marks.
Cut wires back until clean copper is exposed, and splice in a new harness connection if you find burnt damage.
Unclip the thermistor harness on the blower housing, and measure resistance from the wires going into the harness.
Compare the reading to an LG thermistor temperature chart, and expect about 11,000 Ω at typical room temperature.
Replace the thermistor if the value is off by more than about 5% to 10%, and remove it with a Phillips screwdriver.
Test the blower housing fuse on ohms resistance, and replace it if it reads OL instead of near 0.00.

Replace the heater canister assembly if needed

Remove the two screws on the front mounting bracket that hold the heater canister assembly in place.
Release the wires from the small retainers at the bottom, and lift the assembly up and out.
Slot the rear of the canister into the metal slot at the back of the bulkhead during installation.
Fit the front tab into the bracket slot while pivoting the canister into place, and reinstall the two screws.
Reconnect the element wires in order, with red at the top, blue in the middle, and yellow at the bottom.
Reconnect the other red wire at the rear thermostat connection point.

Test and clean the moisture sensor bars

Set the multimeter to ohms resistance, and insert the probes into the moisture sensor plug.
Touch a damp cloth or a wet finger to both moisture-sensor strips to create a resistance path.
Slide along the strips and watch for a resistance value across the full length of the bars.
Clean the strips with a wet rag and cleaning solution, or replace the bars, if the meter only reads in certain spots.
If you get a reading along the entire moisture bar, the moisture sensor isn’t the cause of a no-heat issue.

Reinstall the drum and seat it on the rollers

Lower the drum back into the dryer with the belt still around the drum.
Shift the drum until it slots between the bulkhead area and the roller wheel assemblies.
Rotate the drum by hand, and make sure it turns smoothly before continuing.

Route the belt onto the motor pulley and idler pulley

Reach between the drum and blower housing and thread the belt onto the motor pulley by feel.
Thread the belt onto the idler pulley to apply tension to the belt.
Rotate the drum and confirm the belt drives the motor, idler, and blower fan without major noise or binding.
Align the belt to the same imprint marker on the top of the drum.

Reinstall the front bulkhead

Slot the bulkhead onto the four fingers that rest on the dryer frame.
Roll the drum while gently pushing the bulkhead toward it so the drum front rests between the rollers and the bulkhead frame.
Reconnect the moisture sensor in the lower-right corner of the bulkhead.
Reinstall the four Phillips screws to secure the bulkhead to the dryer frame.

Reinstall the crossbars, bracket, steam system, and wiring

Reinstall the crossbars, and loosely install the rear screws that secure them at the back of the dryer.
Fit the interface mounting bracket into its two metal slots, and reinstall the four bracket screws.
Slot the steam system housing into the sidewall and push it forward to lock it into place.
Reposition the control board, reconnect the steam hose, reinstall screws, and confirm the ground strap is in the correct slot.
Route the wire harnesses to the front through the metal bracket, and reconnect the light switch harness.

Reinstall the front door cover

Hang the front cover on the two large fingers at the bottom of the dryer, and pivot the cover toward the dryer to seat it.
Reconnect the door switch harness before installing the screws.
Reinstall the six Phillips screws that secure the cover, with two at the top and four around the door opening.

Reinstall the control interface and reconnect its harnesses

Seat the control interface into the metal bracket and press it fully into place.
Route the three interface wire harnesses through the bracket, and reconnect them at the rear of the dryer.
Adjust the control board position slightly if needed so there’s enough room to connect the harnesses.
Reinstall the screws that secure the control interface to the metal bracket.
Some models use screws behind the bracket on the left and right sides instead of the steam tray area.

Test for heat and troubleshoot remaining causes

Run a test cycle to verify the dryer heats, even if the steam tray and top panel are still removed.
Reinstall any removed covers and assemblies after you confirm proper operation.
Check the vent for lint obstructions if the dryer still doesn’t heat after electrical and sensor tests.
Consider checking power output from the main board to the heating element, or call a technician for advanced diagnosis.

Reassemble the dryer completely and verify proper heat before pushing it back into place. Repair didn't go as planned? Ask our Answers community for help.

«How to Troubleshoot an LG Dryer That Won't Heat» — автор Ben Schlichter, iFixit, лицензия CC BY-NC-SA 3.0. Показано без изменений. Открыть оригинал и комментарии →