Why does the water pressure get weaker the longer I leave the faucet running?
Hi, my name is Jacob Lantz, owner of Lantz Home Services here in Central Texas. And we get calls about inconsistent water pressure quite often.
There are 2 major reasons this happens to homeowners and 1 wild one that I’ll share with you.
Pressure Reducing Valve (PRV) Issue
What is a Pressure Reducing Valve (PRV)?
First, is the most obvious. Most homes, especially homes on municipal water systems, are required to have a Pressure Reducing Valve (PRV). The PRV is designed to protect the home from fluctuating and increasing water pressure caused by the city. If your home does not have one, or one fails, it can be catastrophic as water pressures can exceed 80 PSI and skyrocket to over 110 PSI. The 2021 International Plumbing Code established that all homes should have no more than 80 PSI.
While most water supply lines are rated for 125 PSI, we’ve seen connections blow at 90 – 110 PSI. Items that are prone to bursting over 80 PSI are RO systems, water filters that serve ice makers, pre softener treatment, and bidet toilets.
The PRV is a plumbing mystery, as there really isn’t much warning until it actually happens. We encourage our techs to check our customers’ water pressure on every visit, whether it’s a toilet clog, gas line repair, or a faucet install, at no extra cost. Lantz Home Services has the Plumbing System add-on to our Ultimate Home Care Plan, and this is an annual inspection of your home’s plumbing system, including checking your water pressure. So, if you’re a member you’ll get at least one check a year from our plumbing experts. Ask your trusted plumber the next time they’re out for a complimentary pressure check! And if they don’t have a gauge, tell them to go get one and come back for free, as it’s their responsibility, in my opinion, of course!
Types of PRVS
Another thing to think about is the type of PRV you have installed. Here in the Austin Metro Area, we have different codes for different municipalities. Places Like Lago Vista, Cedar Park, Jonestown, and Horseshoe Bay all allow a plastic top housing on the PRV, which is the most economical valve choice. The other option is the brass top which is required in Water District 17; Hudson Bend, Steiner Ranch, Parts of Lakeway. These valves are a bit pricy, but will definitely hold long term value. We offer both when giving you options for replacement.
Water Softener Issues
Second major reason for water pressure issues, is your water softener. This will mimic the same water pressure issues as a faulty PRV in that as soon as you turn your sink faucet on the pressure is normal and then slowly dies off. This is caused by resin beads that have broken loose, traveled into the system and are now trapped. When water comes out of the faucet, the resin beads rush to the tap and quickly clog the aerators, which reduces the water pressure. Warning, if this happens, you are going to need to replace your water softener, as well as have every single line, aerator, water heater, and filter in your home flushed and cleaned. This is not a small task. This is why you don’t by that cheap water softener the guy down the road is installing for all your neighbors!! For major projects, such as whole-home water treatment systems, always call a licensed professional plumber to give you the correct service and guidance.
The Third Issue Only Expert Plumbers Know to Check For
And the third is one that I have personally ran into a handful of times in my 25 years of plumbing (wow, I can’t believe I’ve been doing this that long!). The phantom coupling or cap fitting that somehow got stuck inside a fitting two sizes bigger, and the plumber did not see it hiding in there when it was installed. To the plumbers that have had this happen to you, my heart goes out to you! But, we have to check our fittings!!! It’s part of giving customers a professional installation that they can enjoy for years to come.
If it’s a cap, it will jostle around for a few days, few weeks or even years. You’ll call plumber after plumber out to fix your illusive water pressure issue that serves one, two or maybe a full bathroom and every plumber will come up empty handed. Until one “inspector gadget” plumber wanting to impress the customer gets authorization to break out the Sawzall and starts cutting anything and everything in their path. That’s a little extreme, but surgery is necessary. An experienced plumber will know when to take these extreme measures to solve the problem.
Hopefully you never have to deal with the third one, or even number two. But number one is inevitable. Prepare for it and have your PRV checked annually. That’s the only way to know if it is deteriorating and unable to hold the pressure down.
Ultimate Home Care Plan
If remembering to schedule an inspection for your home’s plumbing system isn’t another thing you want to remember, let us do the remembering for you. With the Ultimate Home Care Plan you get Central Texas’ top plumbing, HVAC and electrical experts ready to serve your home with priority scheduling, discounted or waved trip fees, and over 50 years of experience in bringing peace of mind to homeowners from Austin to Lago Vista.
Leave it to Lantz.
If you or someone you know, lives in the greater Austin area and is in need of plumbing, air conditioning, heating or electrical services don’t hesitate to give us a call at 512-710-1032. We’d be happy to send one of our highly-reviewed technicians to handle any issues your home may be experiencing. Not experiencing any issue but still want to learn about our memberships? Give us a call and we can set you up today.