It is generally recommended to let hot water cool down before pouring it down the kitchen sink drain. Here's why:
PVC pipes: Many modern kitchen sink drain pipes are made of PVC (polyvinyl chloride) material. While PVC pipes are generally heat resistant, pouring very hot water directly into them can potentially soften or damage the pipes over time. Gradually cooling the water before pouring it down the drain helps prevent any potential harm.
Grease and fats: Hot water can temporarily liquefy grease and fats that may be present in the drain, but as it cools down, these substances can solidify and create blockages in the pipes. Allowing the water to cool before pouring it down the drain gives the grease and fats a chance to solidify further along the pipe system or in a grease trap, reducing the risk of clogs.
Environmental impact: Pouring hot water down the drain unnecessarily consumes energy. Allowing it to cool before disposal reduces energy waste and is more environmentally friendly.
To properly dispose of hot water from cooking or other uses, it's recommended to let it cool down first and then dispose of it in a suitable manner, such as pouring it into a heat-resistant container or down the drain at room temperature. Additionally, it's important to avoid pouring large amounts of grease, oil, or food scraps down the drain, as these can contribute to clogs and plumbing issues.