How Can You Tell When a Pressure Reducing Valve is Bad or Starting to Fail?

Pressure Reducing Valves that were installed below ground tend to last and operate correctly for about 12 to 15 years. That said, we have seen them fail in less than 5 years but also last for 20 years.

Longevity greatly depends on the environmental conditions that surround the devices in question. Meaning if the valve box that encases the PRV is packed with years of mud runoff and wet clay, then the longevity will be limited compared to how the city plumbing codes require us to install the replacements now. But ultimately the PRV has a limited life expectancy and age is another factor.

A Pressure Reducing Valve (PRV) fails in a handful of different ways. We have some simple tests that we can perform to be conclusive, but usually, we can diagnose this issue over the phone and then validate it upon arrival for the service call. Below are some of the most common failure reasons and some of the symptoms that correspond to that type of failure:

• Low Water Pressure: The most common issue or sign of a PRV problem is low water pressure. This drop-off can be somewhat sudden, but it is usually barely noticeable or happens over a period of time and just continues to get worse. More specifically, if your pressure seems fine with one fixture on but you notice a drop in overall water pressure when a second fixture is used (faucet or toilet), that is an indicator. It can be further determined by turning on a third fixture to see if further overall pressure is lost. Often, we see almost no water pressure once a third or fourth fixture is turned on. A normal, fully operational home should have zero to minimal noticeable pressure loss when a second or third fixture is turned on. Occasionally you might see a slight drop when an unrestricted bathtub faucet (4+ GPMs) is being used full blast versus a California Restrictor “restricted” vanity faucet (only 1.5 GPMs), but the pressure drop should be minimal. This diagnosis and pressure loss can be validated with a few tests as long as your hose spigots are fully operational and functioning without any leaks or drips.
• Water Hammering (Water Pipe Noises): The second most common problem with a failing or non-functioning PRV is noises in the water pipes. This phenomenon is called “water hammer.” Although water hammer occurrence is actually pretty specific, the term is often associated broadly with any unusual noises or odd phenomena that occur in your domestic water piping system. Technically speaking, water hammer is caused by too much water pressure or water velocity. It is produced when this excess pressure stops suddenly, such as when a faucet, fixture, or appliance is turned off. Below are some examples of the sounds that you might hear that are often referred to as water hammer. More often than not this is due to the failure or absence of a Pressure Reducing Valve.
• Mystery Water Leak: The third most common issue is a mystery leak. Usually, these start slow, where there is a constant or continual wet or mushy spot in the yard or flowerbed. Sometimes this leak is so slow and extended that shrubs in this immediate area will get diseased and/or die from what is called root rot. This is where being proactive will save you a couple hundred dollars. Digging a large hole approximately 2’ x 3’ wide and 2’-3’ deep is a lot easier to do when it is dry VS. digging that same hole in wet, muddy, gooey, dank, smelly, clay. It takes far less time and you get a better overall finished product when the area is NOT a leaking mud bog. Often people think the leak is in their irrigation and occasionally it is. But a continually active wet area or a rolling, gurgling, mini geyser is almost always coming from the junctions that facilitate the main line to the main shut off and PRV. These devices have a limited life of approximately 12-15 years from installation. Keep in mind that EVERYONE has a shut off valve that is just as susceptible to failure and leaking as the PRV is. But homes built between 2000 and 2015 have double the exposure with the PRV also in this same area.
• Continual and Constant Leaks & Drips: It is not uncommon for a shower cartridge or a faucet stem to require replacement due to a leak or drip. However, sometimes the dripping or leaking problem can also be attributed to too much water pressure. There are neighborhoods in North Texas that have over 120 PSI coming in at the water meter. If your house was built in the 90s or early 2000s when PRVs were not required, then you might not have a PRV in place. Therefore, that 120 PSI is going to every fixture, faucet, and appliance in your home. This excessive pressure can force the water to squeeze through the seal points of the fixture or appliance. This is VERY common with older or weakened toilet fill valves. We see this happen with older tank water heaters as well (pushing through the T&P valve).
• Collapsed PRV/Collapsed Valve: In this scenario, no water is coming into the home, but no leak is present. This is the least likely and rarest of the scenarios, but we have seen this happen. This event can coincide with somebody trying to adjust the pressure on an old PRV or trying to force an old main shut off valve closed and/or opened. Neither is advisable! The PRVs come factory preset at 45 PSI. If caught early enough in the life expectancy of the device (within the first 4-5 years), it can usually be adjusted to its maximum of 80 PSI. This is a significant difference in felt water pressure! If Earl’s Plumbing replaces your Pressure Reducing Valve, we ALWAYS also replace your whole house shut off valve. If you did not know that you had a PRV then you definitely will not know that in that same valve box, there is also a shut off valve that is designated for the homeowner to turn off the water to your house. This is especially important in the case of a leak related emergency. Contrary to popular belief, you (the homeowner) are not supposed to open the meter box near the street and use that shut off to turn off your water. That is why they make it complicated with a locked lid and a special meter wrench required. In some cases, the meter may be your only option. This is especially true if just now is the first time that you are finding out about its existence. We often find these “mystery valve boxes” that should be easily accessible concealed by mulch, shrubs & landscape, buried & encased in muddy clay, or sometimes just too deep to reasonably or realistically access. Or worse, you know where the box is, but it has never been used and the shut off valve handle has rusted off (very common). Do NOT try and turn this valve if it looks like anything other than new—especially if it is the older style gate valve (which looks like a water hose spigot handle).