text: Question: Hi Robert, I live in Saugus, and I am hoping that you can solve an issue that I have been having for the last few months. A few times a week, there is a plastic water line under my kitchen sink that vibrates. At the same time, I can hear both my upstairs and downstairs toilets running. It lasts for a minute or two and then stops. This repeats many times in a day, but it doesn't occur on a daily basis. The plastic line is attached to my reverse osmosis system on one end and the other goes into a metal valve in the wall under my sink. Do you know what might be happening? As always, I appreciate your help and expertise. Thank you, Mary S
  Answer: Mary, thank you for being a loyal reader. The problem sounds like it may be a bad PRV (pressure reducing valve). This is located at the front of the house at the main water inlet. The purpose of the PRV is to reduce the city pressure down to approx. 60 to 70 pounds. Call a local plumber and have them test your PRV and see that the pressure is right. I honestly believe this is going to be the problem. The pressure is fluctuating, causing the noise you are describing. Best of luck.
  Question: Hi Robert, hope you and your family are doing well. I have an issue with a hammer sound when my sprinklers shut off. I had a backyard put in my house in Henderson and there is a roughly 10-foot by 50-foot section of grass. There are two valves with seven sprinkler heads each. When the first valve shuts off, no problem. When the second valve (which comes on right after the first valve) shuts off there is a loud hammer sound. It always had a little hammer sound when it shut off but now it is quite loud. I checked my water pressure at a hose bib and it was 40 PSI. Is it just a bad sprinkler valve? Can you adjust the sprinkler valve to shut off less abruptly? I sure would appreciate your opinion since you are the smartest contractor I know. Feel free to use this in your newspaper column if you think others may be interested. Thanks, Doug E.
  Answer: Hey Doug, nice to hear from you, I hope things are well with you. It could be a bad valve. I'd try replacing that first as it's the least expensive thing to do. Being the pressure is only 40 punds, that shouldn't be the cause. However, the 40 pounds — is that what the city provides out there or do you have a bad PRV? The 40 pounds seems a little low. Typically city pressure, depending on the city, is around 100 PSI. then you use a PRV (pressure reducing valve) to bring the pressure down to 60 pounds. Some cities only provide low pressure, like the 40 pounds that you have. Given that this issue is happening with one of the valves and not all, I am leaning toward the bad valve. Best of luck.