Water Heater Pressure Relief Valve Extension Pipe

In the example below an upper pressure relief valve drain not visible behind vent connector has been tied into the drain for the lower one.

Water heater pressure relief valve extension pipe. 4 termination of the discharge piping can be to any of the following. The temperature steam rating of a combination temperature and pressure relief valve or valves shall equal or exceed the energy input rating in btu per hour of the water heater. The discharge drain extension is typically taken to just a few inches above the floor or in some jurisdictions it may be directed outdoors a solution that i think is risky. Go to our blog post when is a water heater drain pan required.

Serve a single relief device and shall not. The temperature pressure relief valve on a water heater is connected to a drain line so that if the valve opens someone nearby is not shot in the face with hot water. Discharge through an air gap located in the same room as the water heater. Use a 3 4 male iron pipe mip adapter thread it into the prv and carry on with the rest of your pipe.

Measure the distance from the relief valve to the floor. The valve should be connected to a discharge pipe also called a drain line that runs down the length of the water heater tank. The tpr valve will activate if either water temperature measured in degrees fahrenheit or pressure measured in pounds per square inch psi exceed safe levels. I explain that it was routed to a drain to prevent a mess if it discharges but that you would want to see water on the floor if it was dripping or pressure had blown off so that you know.

For more on this. Pan serving the water heater. Not be directly connected to the drainage system. The water heater s temperature pressure relief valve tprv extension pipe is routed upwards.

The pipe must be no more than 6 from the floor to prevent a scalding injury should the valve open. The pressure relief valve extension is plastic and has a couple of elbows leading it to a drain. The discharge piping serving a pressure relief valve temperature relief valve or combination valve shall. You can not reduce the size of the pipe coming from the prv.

There should be nothing between the pressure relief valve and the water heater. If the tpr valve is on top of the water heater install a short piece of cpvc from the valve to the side of the water heater then use a 90 degree fitting to make the turn towards the floor and add a second pipe to carry the discharge down to the catch pan. I always advise the client that the pipe should be copper and should terminate about 6 inches from the floor. Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap.

Connect the relief valve to the opening in the water heater with a pipe wrench or an adjustable wrench. Connect the pipe and elbow to the pressure relief valve. Cut lengths of cpvc pipe to match the ones you re replacing as long as they extend to within 3 inches of the floor. Most pressure relief valves have a 3 4 threaded discharge port.