What is the maximum water temperature that control valves must be set to for individual showers and tub/shower combinations?

The maximum water temperature that control valves must be set to for individual showers and tub/shower combinations is 120°F. This standard is in place primarily for safety reasons, as water temperatures above this threshold can lead to an increased risk of scalding, particularly for vulnerable populations such as children and the elderly.

Setting the temperature at 120°F balances user comfort with safety; it is warm enough for a pleasant bathing experience while minimizing the risk of burns. Additionally, maintaining this standard helps ensure that plumbing installations comply with the guidelines set forth in the International Residential Code (IRC), which emphasizes both operational efficiency and the welfare of occupants.

While temperatures higher than this may be suitable for some processes, they exceed safe levels for residential bathing fixtures, making adherence to the 120°F standard vital for health and safety practices in plumbing design.