What the heck is a TPR valve?
What is it and why is it important. TPR is short for Temperature/Pressure Release valve. It is a safety device on a water heater. It is there to keep the water heater from exploding. If the temperature and or the pressure were to get high in the tank the valve is designed to release that pressure in a controlled manner. Normally the valve is connected to pipes that will direct the hot water and steam that would be released away from the unit, and very often out of the home. The path should be as straight as possible with as few elbows as possible. Sometimes the people who install the water do not fully appreciate the importance of this safety feature. There may never be a need for it BUT if there is, the way that it is installed is critically important. There should be pipes to convey the potentially scalding water away from people. Those pipes should be approved to handle extremely hot liquids. In the picture above the newly installed water heater had a TPR valve and a pipe to carry away potential dangerous water but they were not connected. The placement of most TPR valves is on the top of the water heater. Coincidentally that height is pretty close to the head of most humans. That is reason the pipes connected to the TPR valve generally go out and down. We want them to go towards the ground but not end at the ground. That way hot escaping water and steam are not slowed down at the outflow. Too many elbows in the pipes represent places where the flow is restricted building up pressure behind them. This is potentially another hazardous condition. Sometimes DIY may understand the function and may add a conduit for the steam and water but they do not think about where it will go, are they using the appropriate materials or what the consequences are of not doing the work up to standards. Leave the installation to a professional or get get accurate instructions from the manufacturer and don't cut corners with the installation.