#Water heater overflow pipe requirements full size
#Water heater overflow pipe requirements code

Item 5 requires that the discharge piping serving relief valves, discharge to the floor, to the pan serving the water heater or storage tank, to a waste receptor or to the outdoors.

#Water heater overflow pipe requirements code

The code is silent as to the size or shape of the waste receptors and the gravity drain line size for capturing and conveying the discharge water from relief valves. Figure 3 illustrates an approved means of connecting the discharge from multiple water heater relief valves. Item 4 requires the discharge piping serve only a single relief device and that it shall not connect to piping serving any other relief device or equipment.

#Water heater overflow pipe requirements full size

Item 3 requires the discharge piping not be smaller than the diameter of the outlet of the valve served and must discharge full size to the air gap. Item 2 requires the discharge to terminate through an air gap located in the same room as the water heater. Although an air gap is already required for the protection of the potable water supply in Section 608.16.1, a plumber or other authorized installer might not realize that the termination point of the relief valve discharge pipe shall also provide for an airgap. Item 1 states the discharge piping not be directly connected to the drainage system. Because the discharge piping from these safety devices that serve water heaters are an extension of the potable water distribution system, the outlet of the discharge pipe must be treated as a potable water supply system outlet. These sections address the requirements of discharge piping serving a pressure relief valve, temperature relief valve or combination temperature and pressure relief valve. These items are mentioned in Section 504.6 of the International Plumbing Code (IPC) and Section P2804.6.1 of the International Residential Code (IRC). There are other important items associated with the relief valve. Any water discharge from the relief valve is an indication of a water distribution system problem, a water heater problem or that the relief valve is malfunctioning.

If the water heater is operating properly, the pressure in the water distribution system is no greater than is required by the code, and the relief valve is in proper operating condition, then there should not be any water discharge from the relief valve. A water heater temperature and pressure relief valve is an important safety device for water heaters as well as the water distribution system to which it is connected. The water heater installed in a home can be a ticking time bomb if not installed correctly or maintained properly. Water Heater Temperature and Pressure Relief Valve A new edition of CodeNotes - Water Heater Safety in the I-Codes (based on the 2018 IPC and IRC) - provides an understanding of the detailed requirements on these items from an overall safety viewpoint. It doesn’t take much imagination to envision what could happen when one of these water heaters is not installed properly. Many are installed inside a living space and tucked away in a closet. The location of a water heater is always a concern.