The answer to 'how to unclog pressure regulator' is to disassemble and clean the regulator. Start by turning off the water supply to the regulator. Then remove the regulator from the pipe and disassemble it, removing any debris or buildup inside. Use a small brush or needle-nose pliers to carefully clean the internal components. Once clean, reassemble the regulator and reinstall it, making sure all connections are tight. Turn the water back on and check for proper operation.
Unclogging a pressure regulator is a relatively simple DIY task, but it's important to turn off the water supply first to avoid leaks. If the regulator is still not functioning properly after cleaning, or if you're uncomfortable performing the repair, it's best to call a professional plumber.