Narrow it down first
- One faucet or shower: Unscrew the aerator or showerhead and soak it in vinegar. Mineral buildup is the usual cause.
- Hot water only: Points to the water heater: sediment in the tank or a partly closed valve.
- Whole house, suddenly: Check that the main valve is fully open, then check with neighbors. It may be a utility main break or maintenance.
- Whole house, gradually over years: Often corroded galvanized pipes narrowing from the inside, or a failing pressure-reducing valve.
Hills and pressure
Johnson City's terrain rises and falls a lot over short distances, so water pressure genuinely differs from street to street. Homes higher on a ridge can see lower pressure, and homes down in a hollow can see pressure high enough to need a regulator. A plumber can test your pressure in a couple of minutes with a gauge on an outdoor spigot.
Fixes
Depending on the cause: replacing a pressure-reducing valve, flushing the water heater, replacing corroded supply lines, or repairing a hidden leak that's stealing pressure. Homes on private wells, common in rural Washington County, may need the well pump's pressure switch or tank looked at.