Why Is My Samsung Washing Machine Not Heating the Water?
Run a short 60°C cotton cycle with no laundry inside and feel the drum door glass after 10 minutes — if it stays cold, reset the machine by unplugging it for 5 minutes and trying again; this clears minor control board glitches and resolves the fault in a significant number of cases (takes about 5 minutes).
Fault description
When a Samsung washing machine fails to heat water, the wash cycle appears to run normally — the drum fills, agitates, and drains — but the water temperature never rises to match the programme you selected. You may notice that clothes come out less clean than usual, detergent residue is left behind, or biological stains are not removed. On some models a temperature indicator on the display simply never advances.
The heating system in a washing machine involves several components working together: a heating element submerged at the bottom of the drum, a temperature sensor (NTC thermistor) that monitors water temperature, and the main control board that decides when to switch heating on and off. A failure in any one of these parts — or in the wiring connecting them — can result in cold washes across all programmes.
Because this fault involves electrical components carrying mains voltage, some steps below require care. Always disconnect the machine from the mains before opening any panels.
Causes
- Failed heating element — The heating element is the most common reason a Samsung washing machine stops heating. Over time, limescale build-up or normal wear causes the element to burn out, breaking the circuit so no heat is produced regardless of the programme selected.
- Faulty NTC thermistor (temperature sensor) — The NTC thermistor continuously measures water temperature and sends readings to the control board. If it fails or drifts out of calibration, the board either never activates the heater or cuts it off prematurely, resulting in a cold wash.
- Defective main control board (PCB) — The PCB controls the relay that switches power to the heating element. A damaged relay or burnt track on the board means the heating circuit is never completed, even though the element itself may be perfectly functional.
- Wiring harness damage or loose connections — The wires connecting the heating element and thermistor to the control board can corrode, chafe, or work loose over years of vibration. A broken or intermittent connection interrupts the heating circuit without any obvious external sign.
- Tripped or blown thermal cut-out — Samsung washing machines include a thermal cut-out fuse as a safety device. If the machine has previously overheated — due to a blocked pump or restricted airflow — this fuse blows and permanently disables the heater until it is replaced.
- Incorrect programme or temperature setting — Some eco and quick-wash programmes on Samsung machines are designed to run at very low temperatures (20°C or below) to save energy. If the temperature dial or digital selector has been accidentally changed, the machine behaves correctly but simply does not heat to the expected level.
Step-by-Step Fix
- 1
Verify the programme and temperature setting
Before investigating hardware, confirm the selected programme is not an eco or cold-wash cycle. On Samsung machines with a digital display, the target temperature is shown on screen; on dial models, check the temperature selector is not set to 20°C or the cold symbol. Select a 60°C cotton programme and run a short test cycle to confirm the fault is genuine.
- 2
Reset the machine
Unplug the washing machine from the mains socket and leave it disconnected for at least 5 minutes. This allows the control board capacitors to fully discharge and clears any temporary software error that may be suppressing the heating circuit. Plug back in, select a 60°C programme, and check whether the door glass warms up after 10–15 minutes.
- 3
Test the heating element with a multimeter
Disconnect the machine from the mains. Remove the rear panel (usually held by two or three screws at the top). Locate the heating element at the base of the drum — it has two spade connectors. Disconnect the wires and set your multimeter to resistance (Ω). A healthy element reads between 20 Ω and 50 Ω; a reading of zero (short) or infinite (open circuit) confirms the element has failed and needs replacing.
- 4
Check the NTC thermistor
The thermistor is usually clipped into the heating element assembly or mounted nearby on the drum casing. Disconnect its two-wire connector and measure resistance with a multimeter. At room temperature (around 20°C) a working NTC thermistor typically reads 10,000–15,000 Ω. A reading far outside this range, or an open circuit, means the sensor is faulty and should be replaced before condemning the element.
- 5
Inspect wiring and connectors
With the rear panel still removed, trace the wiring loom from the heating element and thermistor back towards the control board. Look for burnt insulation, corroded spade terminals, or connectors that pull apart with minimal force. Gently tug each connector to confirm it is fully seated. Corroded terminals can sometimes be cleaned with electrical contact cleaner and a small wire brush.
- 6
Check the thermal cut-out fuse
The thermal cut-out is a small cylindrical or disc-shaped component wired in series with the heating element, often clipped to the element body or nearby bracket. Test it with a multimeter set to continuity — a healthy fuse gives a beep or near-zero resistance reading. No continuity means it has blown and must be replaced with an identical-rated part; do not bypass it, as it is a critical safety device.
- 7
Inspect the control board heating relay
If the element, thermistor, fuse, and wiring all test as good, the fault is likely on the main PCB. With the machine unplugged, locate the control board (usually behind the top or front panel depending on model). Visually inspect the board for burnt marks, swollen capacitors, or discoloured areas around the heating relay. A visibly damaged board needs professional assessment or replacement — this is not a component that can be repaired at home.
When to call a service technician
If you have tested the heating element, thermistor, and thermal cut-out and all components measure within specification, the fault almost certainly lies with the main control board. PCB diagnosis and replacement involves working with mains-voltage circuits and requires specialist equipment to confirm before parts are ordered. Attempting board-level repairs without experience risks further damage to the machine or a safety hazard.
You should also contact a service technician if you find burnt wiring, a melted connector, or any sign of arcing inside the machine. These indicate a more serious electrical fault that goes beyond a straightforward component swap and must be assessed by a qualified professional before the machine is used again.
Prevention
The parts most commonly replaced when a Samsung washing machine stops heating are the heating element, the NTC thermistor, and the thermal cut-out fuse. Using genuine Samsung-compatible parts ensures the correct resistance and temperature ratings, which matters for both performance and safety. Running a monthly drum-clean cycle at 60°C or 90°C helps dissolve limescale before it builds up on the element surface and shortens its life — particularly important in hard-water areas.
Search for compatible heating elements, thermistors, and thermal cut-outs for your specific Samsung model using the parts finder below.
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Frequently Asked Questions
Can I still use my Samsung washing machine if it is not heating the water?
You can continue using it on cold-wash programmes without causing further damage in most cases. However, cold water will not effectively remove grease, bacteria, or heavy soiling, and detergents designed for warm washes will not activate properly. It is best to get the fault repaired before relying on the machine for hygiene-sensitive items like towels or bedding.
How do I know if it is the element or the thermistor that has failed?
Test both with a multimeter as described in the steps above. A failed element will show infinite resistance (open circuit) or zero resistance (short circuit). A failed thermistor will show a resistance value far outside the 10,000–15,000 Ω range expected at room temperature. Testing both before ordering parts saves time and money.
Is a Samsung washing machine not heating water dangerous?
In most cases the machine is safe to run on cold cycles while you arrange a repair. The exception is if you have found burnt wiring, a melted connector, or any smell of burning — in those situations stop using the machine immediately and have it inspected by a service technician before running another cycle.
How long does a washing machine heating element typically last?
In average use, a heating element lasts between 5 and 10 years. Hard water significantly shortens element life because limescale acts as an insulator, causing the element to overheat and burn out prematurely. Using a descaling product or running regular hot maintenance washes can extend element life considerably.
Why does my Samsung washing machine heat on some programmes but not others?
This usually points to a partially failing thermistor or a control board issue rather than a completely dead element. The thermistor may be giving inaccurate readings that cause the board to cut heating short on higher-temperature programmes. It can also indicate a software glitch — try a full power reset first, and if the problem persists, test the thermistor resistance as described in the guide above.