Water Heater Relief Valve Extension Pipe

Another common issue issue identified by our inspectors.

Water heater relief valve extension pipe.

The pipe itself needs to be either copper cpvc or galvanized water piping. I always advise the client that the pipe should be copper and should terminate about 6 inches from the floor. Connect the relief valve to the opening in the water heater with a pipe wrench or an adjustable wrench. 8 termination of the tpr drain pipe cannot be more than 6 inches or less than two pipe diameters above the floor ground or waster receptor.

The pressure relief valve extension is plastic and has a couple of elbows leading it to a drain. 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. Measure the distance from the relief valve to the floor. Cut lengths of cpvc pipe to match the ones you re replacing as long as they extend to within 3 inches of the floor.

Apply ptfe tape or your preferred pipe dope to the threads of the pipe. Most residential water heaters have a 3 4 threaded opening for the discharge pipe. The relief valve on your water heater has a pipe attached. A trapped tpr dischage pipe is a common defect when a replacement water heater s tpr valve is lower than the original one and the installer connects to the exisitng discharge piping at the wall.

The water heater s temperature pressure relief valve tprv discharge pipe is too short. Place one wrench on the tpr valve to prevent the valve from moving a pipe wrench works well. Cut the new pipe to length. Guidelines concerning these valves and their discharge pipes reflect real hazards that every homeowner and home inspector should take seriously.

Use the first wrench to hold the tpr in place when you use the other to unscrew the drain pipe. Although a tpr valve might never become activated it is an essential safety component on boilers and domestic water heaters. 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. The water heater s temperature pressure relief valve tprv extension pipe is routed upwards.

Connect the pipe and elbow to the pressure relief valve. 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. By code you have to run the same size as the opening which means the pipe needs to be 3 4 in diameter. 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.