The answer to 'what causes supply line' is a supply line leak or burst, which can be caused by a variety of factors. Supply lines are the flexible hoses that connect water-using appliances and fixtures to the home's main water supply. Over time, the rubber or plastic material in the supply line can deteriorate, crack, or become damaged, leading to leaks. This can happen due to age, high water pressure, mineral buildup, or physical damage to the line.
Supply line leaks can range from small drips to major bursts, and they can cause significant water damage if not addressed quickly. Homeowners should regularly inspect supply lines for any signs of wear or damage, and replace them if needed to prevent costly leaks and water damage.