The pressure relief valve is usually located at the top of the water heater. It consists of a lever that flips up and down, and it's connected to a pipe that runs the vertical height of the water heater to a drainage spot.
No matter what kind of water heater you have, the pressure valve will be located either on the top or side of the unit. Most likely, it will be near the electric supply or hot water output tube. Don't confuse it with the drain valve, which is used to empty the water out of the heater.
How to Find the Water Heater Pressure Relief Valve. Also known as the temperature/pressure relief valve, or the TPR valve, this valve is located near the top of the water heater. It usually features a lever you can lift up or down and has a discharge pipe that runs from the valve down to the water heater's base.
Excessive noise: If your hot water heater is rattling or emitting a high-pitched whistling noise, it's likely the sound of steam trying to escape the tank, which is a sign of far too much pressure pressing against the inner walls. This means the relief valve isn't doing its job and may need replacing.
Leaking and Strange Noises
PRV valve leaking usually means there's a hole in your valve. If you see pressure relief valve leaking, flooding, or if you hear strange noises coming from your PRV, it's time for a replacement.
Failure causes the valve to release pressure before the system reaches the maximum pressure or causes leakage and chattering. Troubleshooting the valve and the system for what's causing the issues is a safe practice.
It's important to remember to close the pressure relief valve on the hot water heater when you are through draining it. Otherwise, water will run out the valve and through the discharge pipe once it refills.
The valve opens when the pressure inside the tank exceeds the preset limit, usually 150 psi (pounds per square inch), or the temperature goes above 210 degrees Fahrenheit.
Prepare the Water Heater for Repairs
Turn off the cold water inlet valve. Turn on the hot water faucet closest to the tank and allow the pressure in the tank to drain. Models with a TPR located on the side need to be drained until the water level in the tank is below the valve.
This is where a pressure regulating valve (PRV) comes in: PRVs are bell-shaped devices located on the main water supply line where the water enters the home, near the shutoff valve. PRVs regulate the pressure in a home and keep it at a safe, steady level.
Do All Homes Have a Water Pressure Regulator? No, and in some cases, you may not need one. Certain municipal supplies regulate their water pressure safely, but if that pressure runs above 80 psi, you'll want to protect your plumbing system by installing one.
A water pressure regulator is a dome-shaped brass fitting that is generally found just past the main shutoff valve, where the main water line enters the house. It usually has an adjustment screw on top.
A pressure relief valve regulates pressure increases in a functioning system. A pressure safety valve rapidly reduces the system's pressure to a safe operating level.
A safety valve is a pressure relief device used to prevent the over-pressurization of a system. On the other hand, a relief valve is a device used to relieve pressure from a system that is already overpressurized. The function of a pressure relief valve is to protect a system or component from excess pressure.
Pressure Relief Valve – $20 to $200
If you notice that the valve is consistently leaking, it may mean that the tank's pressure is too high, or you might simply have a faulty/clogged valve. The cost of a new pressure relief valve is about $20, and repairs may total to $200.
Under normal conditions, the useful safe service life of a pressure relief valve is 10 years from the original date of manufacture. However, the safe useful life of the valve may be shortened by certain environmental conditions and other factors. At times, replacement may be necessary much sooner.
Pressure Relief Valve Replacement
Replacing a pressure relief valve can cost on average between $200 and $300 if hiring a professional, A homeowner can replace their own pressure relief valve with a bit of plumbing experience and a couple of basic tools, and the part alone costs $20.
If your water heater pressure relief valve is working, this is when it will open. This releases steam and hot water from the discharge tube, making your water heater operate safely again.
A relief-valve pipe terminating into a water leak catch pan is not permitted because the pan is not an indirect waste receptor.
Once the valve releases the pressure, it can be reset within seconds by moving the reset handle.
If the pressure reducer will not feed enough water into the boiler to reach the desired cold-pressure setting, before messing with re-adjusting the valve's feed pressure nut and screw, consider that the internal strainer in the valve may have become clogged.
If no date is specified, a pressure relief valve shall be replaced no later than five years following the date of its manufacture.” In industrial refrigeration, the current recommendation is to replace the relief valve on a five-year cycle.