Water Heater Temperature and Pressure Relief Valve Discharge

The installation has several deficiencies. First, the discharge pipe terminates 6 inches above the floor, which meets the maximum height requirement, but the code requires termination not more than 6 inches above the floor and to be piped to a safe place of disposal. The floor drain is 8 feet away, but the pipe terminates 6 inches above the floor, so discharge may not reach the drain, potentially causing water damage. Second, the discharge pipe must be installed so that it drains by gravity. The horizontal run of 12 feet with two 90-degree elbows and one 45-degree elbow may create a trap or low point if not properly sloped. The code requires the pipe to slope downward toward the discharge point. Third, the discharge pipe size must be the same as the valve outlet (3/4-inch), which it is. However, the pipe material must be rated for the temperature and pressure, and copper is acceptable. The vacuum relief valve is not directly related to TPR discharge. Overall, the installation may not fully comply due to potential lack of gravity drainage and improper disposal location.

To comply, the discharge pipe should be sloped continuously downward from the valve to the termination point to ensure gravity drainage. The termination should be directed to a safe place of disposal, such as a floor drain or outside, and must not be obstructed. Since the floor drain is 8 feet away, the pipe could be extended to terminate directly over the drain, but it must maintain the required air gap (typically 2 times the pipe diameter or 1 inch minimum) above the drain. Alternatively, the pipe could terminate outside the building. The number of elbows should be minimized to reduce friction loss. The pipe should be supported to prevent sagging. Also, ensure the discharge pipe is not trapped and that any horizontal runs have a slope of at least 1/4 inch per foot. Finally, verify that the TPR valve itself is functioning and not leaking.