Key Takeaways
- One weak fixture usually means a clogged aerator, showerhead or cartridge.
- Weak pressure everywhere points to pipes, the regulator, the main valve or a leak.
- Old galvanized pipe is a common cause in Rockville's 1950s and '60s homes.
- A sudden drop across the house can mean a leak or a utility issue.
Step 1: One Fixture or the Whole House?
| What you notice | Likely cause |
|---|---|
| One faucet or showerhead is weak | Clogged aerator, showerhead or cartridge |
| Only hot water is weak | Water heater sediment or a valve at the heater |
| Every fixture is weak | Old pipe, pressure regulator, main valve, or a leak |
| Sudden drop everywhere | A leak, or a utility issue in the street |
Clogged Aerators and Showerheads
Mineral scale from Rockville's moderately hard water builds up in aerators and showerheads. Unscrew them and soak them in white vinegar overnight. If the flow is still weak, a worn faucet cartridge may be the culprit. See faucet repair.
Only the Hot Water Is Weak
Sediment in the water heater, a partly closed valve at the heater, or corroded nipples on top of the tank can restrict hot water only. A flush and a check of the connections often fixes it. See water heater repair.
Old Galvanized Pipe
In many of Rockville's 1950s and '60s homes, galvanized steel supply lines have been narrowing from the inside for decades. Pressure drops gradually and rusty water shows up after the water has been off. The fix is replacing the pipe. See our guide to mid-century home plumbing and repiping.
A Failing Pressure Regulator
Many homes have a pressure-reducing valve where the water line enters the house. When it fails, pressure can drop too low or climb too high. Banging pipes and dripping relief valves can mean pressure is too high. Replacing the regulator restores it.
A Partly Closed Main Valve
After a repair, the main shut-off is sometimes left partly closed. Make sure it's fully open. If it's an old gate valve that won't turn, it may be partly blocked inside. Replacing it with a quarter-turn valve fixes both problems.
A Hidden Leak
If pressure drops and your water bill climbs, check for a leak. Turn off every fixture and watch the meter. If it moves, call for leak detection. Our leak guide walks through the test.
If your neighbors have low pressure too, contact your utility (the City of Rockville or WSSC Water) before calling a plumber. The problem may be in the main.
We track down pressure problems across Rockville, North Bethesda and Silver Spring.
