If your water heater’s T&P valve is acting up, it can be hard to know if the issue is minor or serious or to find the root cause of the issue. A T&P (temperature and pressure) valve keeps excess temperature and pressure from building up in your water heater’s tank. Without it, your unit could explode. Fortunately, you can tell when the valve goes bad if you know what to look for.
Birmingham homes are full of aging water heaters that show evidence of wear as the years pass. A faulty T&P valve will show clear warning signs that should never be ignored. Below, we’ll cover five signs that your valve is failing so you can take action before disaster strikes.
Quick Takeaways
- A bad T&P valve often leaks, drips, or releases water unexpectedly.
- Corroded or stuck valves and mineral buildup are common signs of trouble.
- A T&P valve that won’t open or reseal is unsafe.
- A leaking discharge pipe is not normal and should be fixed.
- Pressure or temperature issues inside your tank can cause T&P valve problems.
- If your T&P valve is failing, have a licensed plumber inspect or replace it immediately.
What a T&P Valve Does and Why It Matters
As your water heater’s tank gets hotter, the pressure inside it rises, and the water and steam it contains take up more space. If the tank’s internal temperature rises past 210°F or its pressure exceeds 150 PSI, there’s a risk it could rupture, so the T&P valve will open to release steam through a discharge pipe. This action lowers the pressure inside the tank and prevents dangerous explosions.
T&P valves aren’t just a convenience; they’re a critical safety device. Many plumbing codes (like the Uniform Plumbing Code) and local municipal codes require water heaters to have functioning T&P valves to prevent catastrophic property damage.
Signs Your T&P Valve Is Bad
Checking your T&P valve regularly is a good way to ensure it’s in good working order. If you notice any of the five signs of trouble below, it’s time to call a plumber for help.
1. The T&P Valve Is Constantly Dripping or Leaking
If your T&P valve drips occasionally, it could be a minor issue caused by the normal thermal expansion your tank experiences every time it heats up. If you notice moisture around your valve from time to time, it may be functioning properly for now, but you may need to replace the valve.
A constant flow of water indicates a more serious problem like a failed valve, broken thermostat, or dangerously high temperature and pressure pushing water out of your tank. You need to deal with this issue immediately to avoid the potential for property damage or scalding should the tank rupture.
2. Water Comes Out of the Discharge Pipe
T&P discharge pipes direct water and steam away from your water heater when the valve opens. This prevents water from causing injuries or damaging the water heater, walls, or floor.
If you notice water leaking from your discharge pipe, it usually means that the water heater is overheating or operating under excessive pressure that could cause it to burst. This is a serious issue that you need to address right away.
3. The Valve Won’t Open When Tested
T&P valves stay closed by default unless they need to release water or steam. You can manually test your valve by placing a container under the discharge pipe to catch water, then carefully lifting the valve’s lever to let water flow out, then returning it to its original position.
If water doesn’t flow, or the valve gets stuck or leaks after testing, you’ll need to replace it. A stuck T&P valve can be dangerous when it prevents your water heater from releasing excess heat and pressure, so you shouldn’t ignore it.
4. The Valve Opens but Won’t Close
T&P valves are designed to stay closed under normal conditions. If your valve doesn’t shut and stays open after it operates, it’s malfunctioning or signaling that you have too much pressure in your system.
When your T&P valve fails to stay closed, its internal seal could be worn out. Hard water can also cause mineral deposits (scale) to build up on the valve’s seal, prevent it from closing, and cause it to leak.
5. Visible Rust, Corrosion, or Mineral Buildup
If you see rust, corrosion, or scale on or around your T&P valve, it signals that the valve is leaking and failing. Over time, the minerals in your water can react with oxygen in the air and speed up the valve’s age-related deterioration.
Rust, corrosion, and scale can prevent the valve from opening and sealing properly, which can cause it to leak, get stuck, or fail at any time.
Why a T&P Valve Fails in the First Place
T&P valve failures have many root causes, which could include:
- Age and normal wear
- Excessive water pressure
- Thermal expansion issues
- Sediment buildup inside the tank
- Poor water quality or mineral content
Is a Leaking T&P Valve Dangerous?
A leaking T&P valve is dangerous because it indicates that the water in your tank is extremely hot and pressurized. A constant leak indicates that the valve’s safety mechanism is failing and your water heater is under stress, which could damage your tank and lead to failure.
Heavy leakage can also cause mold and mildew growth that can harm your health, so you need to address the issue quickly.
Can You Fix a Bad T&P Valve Yourself?
While in theory it’s possible to fix a bad T&P valve yourself, doing so can be risky. A repair job gone wrong could result in thousands of dollars’ worth of damage to your tank and your property.
Removing an old and corroded or rusty valve yourself could damage your water heater. You could also injure yourself if you get exposed to steam or boiling water while you work. If you fail to follow the plumbing codes and install the wrong valve (or misalign the right one,) it could fail to function or seal properly.
If you lack plumbing experience, don’t know why your valve is leaking, or suspect that you have a serious problem with your water heater, hiring professional service is always the smart move. A licensed plumber will ensure your repair is done properly and in compliance with local codes.
When a Bad T&P Valve Means a Bigger Water Heater Problem
A problem with your T&P valve usually signals that the valve itself is faulty or that you have a serious buildup of heat and pressure in your water heater. A plumber can inspect your system to see if you have a problem with your pressure regulator or expansion tank.
If replacing the valve, flushing away sediment, replacing your expansion tank, or making relevant repairs doesn’t resolve the issue, you may need to replace your water heater.
FAQ: T&P Valve Questions Homeowners Ask
How often should a T&P valve be replaced?
Most T&P valves last three to five years, although they can last the entire life of your water heater (up to fifteen years.) If your valve is more than five years old or you notice that it shows signs of wear, moisture, or improper sealing, you should hire a plumber to inspect it.
Is it normal for a T&P valve to drip occasionally?
It’s normal for T&P valves to shed a few drops of water every once in a while when the temperature and pressure inside the tank reach their upper threshold. A persistent or heavy drip indicates a more serious problem.
What happens if a T&P valve fails completely?
If your T&P valve totally fails, it will not release pressure from your water heater. This can cause heat and pressure inside the tank to continue to rise. If overheated, pressurized water escapes the tank unexpectedly; it could flood your home and cause serious burns to anyone nearby.
Can a bad T&P valve cause my water heater to burst?
Saying that a faulty T&P valve can cause a water heater to burst is not a myth. A faulty valve will not stop your water heater from overheating, and the increase in pressure could strain your tank enough to cause a sudden failure.
Should I shut off my water heater if the T&P valve is leaking?
If you notice that your T&P valve is leaking, turn off the cold water supply as well as the breaker or gas switch that allows the heating element to function. Do not adjust or tamper with the valve; call a plumber to make the repair.
Water Heater Repair and T&P Valve Replacement in Birmingham, AL
When your T&P valve is malfunctioning, ignoring the issue can put your household and property in danger. Fortunately, the experts at Birmingham Benjamin Franklin can diagnose and repair your faulty valve fast. Our trusted plumbers serve several communities in the Birmingham, AL, area, including Bluff Park, Hoover, Inverness, Mountain Brook, Riverchase, Vestavia Hills, and more!
If your T&P valve is leaking or failing, our team will be there when we say we will. When you need punctual plumbers, Benjamin Franklin Plumbing is the name you can trust, so call us for service today!