A while back I wrote about getting my water pressure back from the PSI trolls. It turns out, I was too ignorant to know what real water pressure was like and misjudged my victory. So recently I set out to avenge this injustice. I contacted the local water company to have a look.

I had specific requirements for said support. I wanted to know the PSI and flow (in gallons per minute) of my water source. The technician performed his job while I was at work, and when I arrived home I found the small note explaining the details of his work:

120 p.s.i., flows looks good.

What the hell does the “looks good” mean? I did call and ask. I got a distinctly unsatisfactory answer. So I took matters into my own hands.

A quick run to Home Depot supplied me with everything I thought I might run into. I had dug up a portion of the yard near the meter to assess the situation. One such item was the curb key needed to shut off the city’s water supply to the house. I had previously performed this action with an adjustable wrench. I think I ruined something in my arm. The first action was to remove the pressure reducing valve (PRV). That proved somewhat difficult because of the tight space to work in. My perseverance paid off and I was able to remove it quickly. I then cleaned out the mesh on the input side of the valve and screwed it back into the line. This proved completely ineffective. The next thing to do was to replace the PRV altogether. Having purchased an appropriate unit at Home Depot for less than $30, I was ready to finish the job. I put the new PRV in place and tightened everything down.

When the water was turned back on and pressure restored to the house, I waited to be sure that no leaks were present from my new handy work. I tell you what! No leaks (one slight leak was corrected from the previous equipment), and the water flow was amazing. The pressure was actually lower than I had previously set the PRV to (40psi from 100psi), but the flow was at least 400% better. I had previously measured it at the kitchen faucet at almost ½ a gallon per minute. Now it’s up to the regulated rate of 2 gallons per minute. I was so elated! I went and bought the craziest shower head I could find to celebrate my newfound water pressure. Of course, now I’m at odds with the pressing drought. It’s a grandiose victory nonetheless.

The Fix-It summary:
The problem signature was that water pressure was adequate upon build-up, but fell to 0 psi after seconds of use. The resultant flow was down to around a ½ gallon per minute, which is well below normal. The PRV is there to reduce the pressure of incoming water from a water source – usually the city water source. It is a simple device resembling a spring-shock from a car on the inside. There’s a valve at the end of this shock that controls the flow of water. I’m not really sure how it’s able to control the pressure the way it does, but apparently it is within the realms hydraulic physics. I can tell you, however, that when the PRV goes bad, it fails to control pressure dynamically. So when pressure is good, but flow is not, then it may very well be a problem with the PRV. Check the mesh screen at the intake, and replace the unit if that doesn’t clear up the problem.