Where Is the Hot Water Heater Pressure Relief Valve?

Reactive Plumbing has assisted homeowners with hot water heaters for years. All hot water heaters have a valve to release pressure. These are commonly called T&P valves, and they are essential for safety. Do you know where to find your hot water heater’s T&P valve?

What Is a Pressure Relief Valve?

Every hot water heater has to have a pressure relief valve. These valves prevent the hot water heater from exploding under excessive pressure.

Usually, hot water heaters shouldn’t exceed 150psi. When pressures rise above that, the pressure relief valve opens briefly. Then, a small burst of water releases. T&P valves also open whenever temperatures near the boiling point.

Why Does This Matter?

Hot water heaters are built as a closed system. As such, excess energy can’t escape without opening the system. Since water expands as it gets warmer, pressure can build up quickly. Without a pressure relief valve, the hot water heater could burst.

How Does the Pressure Relief Valve Work?

When your hot water heater was installed, someone set up the pressure relief valve. They set a specific temperature and pressure point to activate it. When those metrics are met, the valve opens. It stays open until the temperature and pressure drop back to safe levels.

The amount of pressure released depends on how the relief valve was set up. Most of the time, it releases 20% or less of the overall pressure. This is called the blowdown phase. Once it reaches safe levels again, it will close automatically.

Where Is the Hot Water Heater’s Pressure Relief Valve?

Typically, the T&P valve is found near the top of your unit. If you think there is a problem with it, you’ll need to locate it to check. Look for a valve that is connected to the tank by a discharge tube. These discharge tubes usually face upwards. The whole apparatus is screwed into an inlet valve on the tank.

How to Open Them

Sometimes, you might need to open the pressure relief valve manually. Before doing anything, take a look at the owner’s manual. It should specify any specific steps that should be followed.

However, in most cases, you’ve just got to lift the valve. Keep lifting it until the brass stem moves. At that point, you should notice hot water rushing through. Lower the valve back down to stop the flow.

Why Do You Need to Open the Pressure Relief Valve?

There are several reasons you might want to open the valve manually. Opening it could help you test whether it works. Also, you can open it to see if there are any leaks. Finally, you might need to relieve excess pressure from the hot water heater.

Testing the Pressure Relief Valve

Reactive plumbing recommends testing T&P valves at least once every 12 months. That way, if there are any problems, you’ll find out about them before anything happens.

Simply open the valve to see whether pressure gets released. If it does, then everything should be functional. Before you open the valve, check to make sure that everything is connected. The valve should connect to a pipe. Also, that pipe should also run into some sort of basin to collect water as it releases.

If everything is in working order, water should flow through the pipe. When it doesn’t, that could be a sign of mineral buildup. From time to time, these pipes become clogged with mineral deposits. When you notice something like that, let Reactive Plumbing know. Blocked pipes aren’t something that you can fix by yourself.

Checking for Valve Leaks

Leaks are the most common issue that you’ll find with your pressure relief valve. Usually, you’ll notice the sound of water leaking first. This could be from a few things, but the pressure relief valve is a common culprit.

When you hear water leaking, you should test it. Use the steps from above to see if it works as usual. If it does, there could be an issue with the hot water heater’s pressure regulator or thermostat. Either way, contact Reactive Plumbing to figure out what’s wrong.

Fixing a Broken Pressure Relief Valve

When there is a problem with your pressure relief valve, you can’t ignore it. Most of the time, broken pressure relief valves suffer from two things: Either the valve won’t open properly, or it might be leaking. In either case, you might need to have a professional take a look at it.

Repairing a Valve That Won’t Move

Some valves become stuck in their closed position. Unless you fix it, then the pressure might build up excessively. If your valve seems stuck, try moving it by hand. A lot of the time, simply opening it a few times will fix any issues.

If that doesn’t work, you’ll need to have a plumber repair it. When the valve is stuck in the open position, nothing can relieve any pressure. When it is stuck in a closed position, your hot water heater won’t work at all.

Repairing a Valve That Leaks

So, you found some water puddled on the floor, and you determined it was from the pressure relief valve. Most of the time, that’s because the valve isn’t connected properly. Look closely at where the valve meets the tank. If you see water coming from there, then you should tighten the valve.

Before tightening the valve, disconnect the water heater first. Otherwise, you could get burnt. Wait until the water cools sufficiently. Then, unscrew the valve entirely. Slowly screw it back into place once you’ve taken it off. Make sure that it fits tightly onto the inlet valve.

Finally, turn the hot water heater back on to see if that fixed the problem. If it didn’t, you’ll need to speak to a professional. More than likely, it’s time to get a replacement.

How to Install or Replace the Discharge Tube

The discharge tube collects water when the valve opens. Occasionally, these may break, and you’ll need to replace them. Screw them clockwise onto the hot water heater’s inlet valve. Most of the time, you won’t even have to turn it off.

Safety Considerations

Don’t touch the pressure relief valve when the hot water heater is still on. You could cause yourself serious burns. If you suspect that something is wrong with the pressure, hire a professional plumber.

Contact Reactive Plumbing to Help With All Your Hot Water Heater Problems

Reactive Plumbing is your premier North Shore plumbing company. They serve anyone living in North Shore, Sydney, or The Hill’s District. If you’ve had any problems with your T&P valve, they can help. They also offer financing options, so anyone can afford their services. Whether you need help with your pipes or the toilet, they’ve got the expertise for the job. They’ll install, repair and service all of your home’s plumbing. Contact Reactive Plumbing next time you have any plumbing issues.

Categories: Plumbing


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