Heating pads (flexible heating mats) are a popular flexible heating category in winter, but the large-area, bendable heating structure makes surface temperature rise the item most prone to exceed limits. Ningbo Xuntong Standard has summarised the high-frequency non-conformities from many submissions and built a practical corrective-action plan to help businesses minimise risk before mass production.

1. Most prone to exceed limits: surface temperature rise

The temperature distribution across a flexible heating surface is often uneven, and local hot spots above the standard limit are the number-one problem. The standard requires the temperature rise of accessible surfaces to stay within the limit, and abnormal tests must verify that the temperature does not exceed the danger threshold when the thermostat fails. Ningbo Xuntong Standard recommends running a temperature-field simulation at the design stage rather than waiting for a failed submission.

2. Structural non-conformities

Insufficient seam strength, water ingress into the controller and unreliable thermostat fixing are common mechanical problems; some low-cost products use only a single thermostat with no thermal fuse and fail the abnormal test by overheating directly. The sealing and fixing method of the controller directly determines whether the product can pass the abnormal operation test.

3. Electrical safety

Leakage current, electric strength and abnormal operation (covering/folding) are mandatory checks. Ningbo Xuntong Standard recommends a redundant design of “double thermostat + thermal fuse” so that even if the main thermostat fails, the backup protection can still cut the power — this is the key to passing the abnormal test.

4. Corrective-action path

Corrections usually start from three aspects: re-laying the heating-wire spacing to even out the temperature field, adding thermostat redundancy, and strengthening seams and controller sealing. Ningbo Xuntong Standard provides pre-testing and corrective-action guidance for heating pads, covering temperature rise, structure and electrical items in full. For related regulations and standards, see the Regulations & Standards section; for appliance testing capability, see the Ningbo Xuntong Standard official website; visit the appliance safety standards resources. Putting testing up front can significantly reduce tooling-change costs.