Quick answer
Your washing machine has developed an electrical fault — usually a failing heating element or motor. Stop using it and have it tested or repaired.
Washing machines are one of the most common causes of RCD tripping because they combine electricity and water. A failing heating element, worn motor brushes, or a damaged pump can all cause earth leakage. If your washing machine trips the RCD, stop using it immediately. Try it on a cold wash — if it only trips on a warm wash, the heating element is the likely fault. Do not keep using a washing machine that is tripping your electrics — it is a safety issue. Call an appliance repair engineer or replace the machine.
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