Thu 21 Feb, 2013 01:50 pm
I recently had a problem where I had low water pressure (close to zero water pressure) in my house. All faucets, all showers, toilets, hose fixtures, etc were just a trickle. And, for the upstairs, barely even a trickle. The root cause was a damaged PRV (Pressure Reducer Valve). The water pressure from the city is about 130psi, which is way too powerful for a house to handle. So, most homes have a PRV in the ground that sets the water pressure coming in to the house. Your appliances in the house can't handle anything above 80psi, so I set my PRV at 70psi just to allow for spikes in pressure. PRV can be set to any psi typically between 5psi and 100psi.
I dug up the PRV and found that it was damaged. The pressure adjustment bolt was completely sheared. There is no repairing that. You have to replace it. To do that, turn off the water at the meter (from the city). Remove the PRV and install a new one. Verify that your seal is good, and turn the water back on at the meter. You are good to go.
In my case, the PRV filter had some debris in it. This can happen if your city does maintenance on the lines in the neighborhood. Sometimes, before the city worker seals everything up, some trash, rocks, debris, dirt, or other items get into the line, especially if the city line is damaged near your neighborhood. So, when the city repairs their pipes and turns the full pressure back on, all that trash, debris, rocks, dirt, etc shoots like a bullet through the lines. It has to end up somewhere right? Well, in this case the trash, rocks and debris found their way into the pipes that go to my property and busted the PRV. In fact, the debris in the pipes shot with such force that the PRV was completely damaged internally, which explains why water pressure in my house went to almost nothing. No water cold get through the PRV. I cost me about $300 (Parts and Labor) to replace the PRV. I wasn't too happy with the city, but it might be more of a headache to take them to court and prove that they ultimately damaged my PRV.
It is good to know that you have changed your PRV yourself because will not be able to take them to court, it is a time taking process and it can also cot more than $300. And you are right, they should clean all the piping system but not in this way.