How to Fix a Washing Machine That Doesn’t Heat Water

A washing machine that doesn’t heat water can affect the quality of your laundry, especially when washing heavily soiled clothes. This issue is often caused by a malfunctioning heating element, a faulty thermostat, or wiring problems. In this guide, we will go through the possible causes of this problem and the step-by-step solutions to fix it.

Understanding How Washing Machines Heat Water

Most washing machines have an internal heating element that warms up the water to the desired temperature. This element is controlled by a thermostat, which regulates the heat. In some cases, the machine relies on a hot water supply from your home’s plumbing system.

When the washing machine fails to heat water, it can result in poorly washed clothes, detergent not dissolving properly, and ineffective stain removal. Identifying the root cause is crucial before attempting any repairs.

Common Causes of a Washing Machine Not Heating Water

1. Faulty Heating Element – The heating element is responsible for warming the water. If it is damaged or burned out, the machine won’t heat the water.
2. Defective Thermostat – The thermostat regulates the temperature. A faulty thermostat can prevent the element from heating up.
3. Wiring Issues – Loose or damaged wires may stop the power from reaching the heating element.
4. Faulty Temperature Sensor – Modern machines have sensors that detect temperature. A defective sensor may send incorrect signals.
5. Control Board Malfunction – If the machine’s electronic control board is faulty, it may fail to send power to the heating system.
6. Water Supply Issues – If your machine relies on a hot water inlet and there is no hot water supply, it will not heat the water.
7. Limescale Build-Up – In hard water areas, limescale can coat the heating element, reducing its efficiency or causing failure.

Step-by-Step Guide to Fixing a Washing Machine That Doesn’t Heat Water

Step 1: Check the Washing Machine’s Settings

Before proceeding with repairs, ensure that the washing machine is set to a hot water cycle. Some machines allow you to adjust temperature settings manually. If the cycle is set to cold, the machine won’t heat the water.

Step 2: Test the Heating Element

How to Check the Heating Element:

• Unplug the Machine: Always disconnect the washing machine from power before working on it.
• Locate the Heating Element: It is usually at the back or bottom of the drum.
• Use a Multimeter:
  • Set the multimeter to the resistance (ohms) setting.
  • Place the probes on the heating element’s terminals.
  • A reading between 20-30 ohms means the element is functioning.
  • If the reading is infinite or zero, the heating element is faulty and must be replaced.

How to Replace the Heating Element:

1. Drain any water from the machine.
2. Remove the rear or bottom panel.
3. Disconnect the wires from the heating element.
4. Unscrew the securing bolts and remove the old heating element.
5. Insert the new heating element and secure it.
6. Reconnect the wires and reassemble the machine.

Step 3: Check and Replace the Thermostat

The thermostat controls the heating element. If it fails, the machine won’t heat water.

How to Test the Thermostat:

• Locate the thermostat (often near the heating element).
• Use a multimeter to check for continuity.
• If there is no continuity, replace the thermostat.

How to Replace the Thermostat:

1. Remove the faulty thermostat.
2. Insert the new thermostat in the same position.
3. Reconnect the wires and secure it properly.

Step 4: Inspect the Wiring and Connections

Loose or burned wires can prevent power from reaching the heating element.

How to Check for Wiring Issues:

• Open the machine’s back panel.
• Look for any loose, burned, or disconnected wires.
• Use a multimeter to check for voltage at the heating element terminals.

How to Fix Wiring Issues:

• If you find damaged wires, cut out the faulty section and replace it with new wiring.
• Ensure all connections are secure and insulated properly.

Step 5: Check the Temperature Sensor

Some machines have a built-in sensor that detects water temperature. If this sensor fails, it may prevent the heating element from activating.

How to Test and Replace a Faulty Sensor:

• Locate the temperature sensor (usually near the thermostat).
• Use a multimeter to check for resistance changes when exposed to different temperatures.
• If faulty, replace it with a new sensor.

Step 6: Inspect the Control Board

A faulty control board may fail to send power to the heating element.

How to Check the Control Board:

• Inspect for visible burns or damaged components.
• Test output voltage using a multimeter.
• If the control board is faulty, it may need to be replaced by a technician.

Step 7: Check for Limescale Build-Up

Limescale can coat the heating element, reducing efficiency. This is common in areas with hard water.

How to Remove Limescale from the Heating Element:

• Use a descaling solution or white vinegar.
• Run an empty hot wash cycle with the solution.
• Repeat monthly to prevent future build-up.

Step 8: Verify the Water Supply

If your machine relies on a hot water inlet, ensure the hot water supply is working.

How to Check the Water Supply:

• Open the hot water tap and check for flow.
• Ensure the inlet hose is not blocked.
• If necessary, clean or replace the inlet filter.

When to Call a Professional

If you have checked all the above components and the machine still doesn’t heat water, it may be due to an advanced electrical fault, a faulty control board, or a problem with internal wiring. In such cases, contacting a professional technician is recommended.

A washing machine that doesn’t heat water can be frustrating, but diagnosing the issue step by step can help you identify and fix the problem. The most common culprits are a faulty heating element, thermostat, or wiring issues. Regular maintenance, such as descaling and checking electrical connections, can help prevent this issue from occurring in the future