Kentucky Master Plumber Practice Test 2026 - Free Master Plumber Practice Questions and Study Guide

The appropriate temperature limit for using a water heater designed for supplying potable hot water in a space heating application is 140 degrees Fahrenheit. At this temperature, the water heater can safely provide adequate space heating without risking damage or hazards that can arise from excessive temperatures, which can affect the integrity of the system and the materials involved.

In applications involving potable water, it's essential to maintain a balance between efficiency and safety. Temperatures exceeding 140 degrees can lead to scalding and can compromise the health of the plumbing system. Furthermore, many local codes and manufacturer guidelines set forth this limit to ensure safe operation in both potable water supply and space heating situations. Keeping the temperature at or below this threshold helps to mitigate risks while still allowing for effective heating capabilities.