Why does a commercial food warmer leak or fail to retain heat?

Please verify the following points and require itemized written supplier responses:（commercial food warmer rice-warmer-leakage） Leaks may come from aged seals, loose joints, cracks or damaged drains; poor insulation may result from impact damage, deformed lids or frequent opening. Stop using leaky, hot-shelled or deformed units to prevent contamination and burns. Define capacity, accuracy, materials and operating environment before requesting quotes on a uniform basis. Request specification sheets, test reports, certificates, maintenance manuals and spare-part lists. During acceptance, verify appearance, dimensions, functions, safety protection and packaging, and keep test records. Do not compare unit price alone; include customization, freight, spare parts, after-sales support and downtime risk. Keep written records of inquiries, confirmations, FAT, acceptance and warranty commitments.