Todays defect spotlight is on the TPR (temperature pressure relief) valve discharge pipe.

The TPR valve is the valve that opens when your water heater develops too much pressure or is too hot. This valve keeps the water heater safe. Without this valve operating properly you run the risk of a catastrophic failure of the water heater.

What is a catastrophic failure on a water heater? Simple. This is when the water heater ruptures and explodes. Well, that’s the worst case scenario. Just google myth busters and water heater and you’ll see what the worst case scenario is when it comes to your water heater. It is the water heater becoming a missile and launching through the roof of your home with explosive force!

This type of failure is something you never want to experience! Thankfully, water heater manufactures have built in a safety valve that will open before the water heater turns into a giant missile of death! This valve is called the TPR valve.

This is the TPR Valve

This is the TPR Valve

Temperature Pressure Relief Valve. This valve is designed to open before your water heater becomes too hot to cause a catastrophic failure and before your water heater builds too much pressure to cause a catastrophic failure. Thus, this very important valve can keep you, your family and your some safe from danger.

What happens when this failure occurs?

When the TPR valve opens it will release water from the water heater. This water will be over 200 degrees hot and will mostly be discharged and steam. Not the friendly tea kettle steam but the 200 degree, burn your immediately kind of steam. When this happens your first action should be to TURN OFF THE WATER.

Most water heaters hold about 40 gallons of water in the US and larger ones can store up to 120 gallons! This water will be pouring onto your floor wetting and damaging anything near by. Leaving the water on will allow hundreds of gallons to discharge into your home. Not only will this damage your possessions near the water tank but could cause structural damage to your home. It is for this reason that you should always be able to easily observe the bottom of the discharge pipe of the TPR discharge.

Cap City TPR Valve Leaking

This TPR Valve is Leaking and is Dangerous

If the TPR discharge pipe is not observable than the early stages of a failure may go unnoticed. One drip can become two, two drips become four, four become eight. You get my point. The longer you allow a TPR discharge to leak the closer you become to a TPR discharge event. Which, as we have noted, will be a very, very bad day.

This is what a TPR discharge pipe looks like. It is a piece of Copper, CPVC or PEX that is attached to the side or top of the water tank. It should extend to within six inches of the floor, by at least three quarters of an inch in diameter and be readily visible.

This article will concentrate on the readily visible part of that requirement.

Cap City TPR Not Visible

This TPR Discharge is Not Visible

If you do not notice your TPR discharge pipe leaking then you will not be able to take corrective action to prevent a future failure. For this reason the TPR discharge pipe should be readily visible.

Cap City TPR Valve Missing

The TPR Valve Missing is missing on this water heater.

When the water heater is located inside this discharge pipe should extended down the side of the unit and within six inches of the floor. In the same room there should be a drain to service the TPR discharge pipe. This can be a floor drain or a drain that is plumbed to the exterior of the home. Whichever type of drain is used the end of the discharge pipe should be readily visible. So that if the valve starts to leak you’ll be able to see it leaking.

Once a month you should purposely look at the bottom of your water heater and check for leaks. Any time you are around your water heater you should keep and eye out for leaks.

A leaking water heater is NEVER SAFE! A leaking water heater is an immediate danger that can quickly cause damage to life and limb as well as your brand new flat screen television.

In conclusion…

This entire article boils down to two statements.

  1. You should be able to see the bottom of your TPR discharge pipe.
  2. You should look at the bottom of your TPR discharge pipe.

Water heaters, and any gas appliance, are some of the most dangerous appliances we have in our homes. They burn fuels that can be toxic, they develop extreme pressure and they can cause real and immediate damage.

BUT! They are some of the appliances that we absolutely can not live without. No hot water? No thank you!

Thank you.