The short answer
An LG washer that seems not to heat is usually running the cycle it was asked to run. Cold and eco programmes wash at low temperatures by design, and a machine plumbed to a cold supply only heats what it draws. Confirm the cycle and the plumbing before suspecting the element, because those two explain most of these complaints.
Causes, ranked for this Lg washer
- A cold or eco cycle selected — Why: Modern programmes wash cool by design to save energy, so a machine behaving exactly as designed produces this complaint whenever the cycle was chosen by habit rather than intent.
- Hot and cold supplies reversed or a tap closed — Why: On machines that take both supplies, a closed hot tap or reversed connections give a permanently cool wash with nothing wrong inside the appliance.
- Heating element failed — Why: This is the real fault and it produces a long cycle that ends cold, because the machine waits for a temperature it can never reach before giving up.
- Temperature sensor misreading — Why: A sensor reading high tells the control the water is already hot, so it never calls for heat and the wash stays cold with a perfectly good element.
- Control board or the heating relay — Why: Last, because each cause above imitates it and none needs a part; a board is diagnosed after the element and sensor are metered rather than before.
What to check, in order
- check which cycle and temperature were actually selected. — Because: it is the top cause and it costs nothing to confirm.
- run a deliberately hot cycle and feel the door glass near the end. — Because: it distinguishes a programme complaint from a genuine heating failure.
- check the supply taps and which hose is on which inlet. — Because: a closed or reversed supply gives a cold wash with nothing internally wrong.
- note whether cycles now run much longer than they used to. — Because: a long cycle ending cold is the signature of a failed element.
Checks you can safely do yourself
- Check the manual for which programmes heat and to what temperature, and note what was actually selected when the complaint occurs. — Tools: the owner manual — Time: several minutes
- Run a deliberately hot cycle with a light load and feel the door glass carefully near the end of the wash phase. — Tools: none — Time: the better part of an hour, mostly waiting
- Check both supply taps are fully open and that the hoses are connected to the correct inlets on the machine. — Tools: a torch — Time: several minutes
- Compare the cycle duration against how long it used to take, noting any substantial increase. — Tools: none — Time: several minutes
- Note whether the breaker holds throughout the heating phase. Stop here: the element and sensor need metering inside the cabinet. — Tools: none — Time: several minutes
Before you open anything
Safety
unplug-before-service branch-circuit-15-20a
A breaker tripping when the wash reaches its heating stage means an element breaking down to earth: stop using the machine and leave the circuit off. Do not test the glass by holding a hand against it for long, since a working machine reaches temperatures that will scald. Unplug before any inspection.
Where the owner fix ends
Checking cycles, supplies and durations is owner work. Call a technician when a deliberately hot cycle stays cold with the taps open and correctly connected, since the element and sensor must be metered inside the cabinet; and immediately when the breaker trips at the heating stage.
Nearest pages of the same kind
Generalized information — what this page does not cover
family model
This page is generalized information about LG washers and covers front-load and top-load machines together, whose heating arrangements, supply connections and cycle temperatures differ. No family-level or model-level page exists in this reference yet; when one is published it will be linked here.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
