Why does my electric underblanket make a clicking or buzzing sound?

A soft clicking sound can happen as the controller regulates temperature, but loud or repeated buzzing is not something to ignore. The manuals describe automatic temperature control and overheat protection, so brief control cycling may be normal, while persistent noise can point to a fault or poor connection. fileciteturn0file2turn0file1

1. Listen to the sound closely and note when it appears. Expected result: a brief click during heating control may be harmless, but continuous buzzing is not.
2. Check that the plug and controller are fully inserted. Expected result: noise caused by a loose connection should stop after reseating the parts.
3. Move the blanket flat on the mattress and make sure it is not folded. Expected result: a folded or creased section can overheat and make the controller work harder.
4. Try a different socket if the unit is otherwise undamaged. Expected result: if the noise changes or stops, the original socket may be contributing to the issue.
5. If the sound is loud, accompanied by heat at the plug, smell or flickering power, unplug the blanket and stop using it. Expected result: the product should not be used again until it has been checked.

Do not use the blanket if the noise comes with scorching, intermittent power or visible damage. If the issue remains unresolved or safe use is uncertain, contact the retailer or store where it was purchased. fileciteturn0file2turn0file11