Answer: Yes. If the sprinkler system drops inlet pressure, the house side can push back against the PRV. That may cause a bypass or check feature inside the PRV to chatter or bang.<\/strong><\/p>\n Adding a check valve after the PRV may seem like a simple fix.<\/p>\n It could stop pressure from pushing back into the PRV.<\/p>\n But it may also create a closed system inside the home.<\/p>\n That means heated water has fewer places to expand.<\/p>\n The expansion tank must be sized and charged correctly.<\/p>\n You can learn more about thermal expansion from Removing the expansion tank is usually not the best first move.<\/p>\n The PRV may include a bypass feature.<\/p>\n Still, that does not always protect every fixture.<\/p>\n There is about 25 feet of pipe before the tank.<\/p>\n Several fixtures may be tied into that section.<\/p>\n Those fixtures could see pressure changes without the tank.<\/p>\n First, check the expansion tank air charge.<\/p>\n It should match the home water pressure.<\/p>\n Second, test the pressure before and after the PRV.<\/p>\n Test it while the sprinklers turn on.<\/p>\n Third, inspect the PRV for wear or chatter.<\/p>\n A weak PRV can make loud sounds under changing flow.<\/p>\n For sprinkler system tips, visit the\u00a0EPA WaterSense sprinkler guide<\/a>.<\/p>\n A licensed plumber can also confirm code needs in your area.<\/p>\n The safest fix may involve PRV service, tank adjustment, or piping changes.<\/p>\n Do not remove safety parts without checking the full system first.<\/p>\n I’m Chris Mayer, writing for Plumbing 101<\/a>.<\/p>\nShould You Add A Check Valve?<\/h2>\n
\nWatts<\/a>.<\/p>\nShould You Remove The Expansion Tank?<\/h2>\n
Best Next Steps<\/h2>\n
![\"Why](\"https:\/\/plumbing101.i234.me\/wordpress\/wp-content\/uploads\/2026\/05\/Why-Your-PRV-Bangs-When-Sprinklers-Turn-On-300x169.png\")