Plumbing · triage
Low water pressure in the whole house
The short answer
Whole-house low pressure is usually the supply (utility work, a partly closed main valve, a failing pressure regulator) or a leak. One tap only: clean its aerator.
Sudden drop plus wet spotsA sudden pressure drop with damp floors, a hissing sound or a spinning meter can mean a leak: close the main shutoff and see the burst-pipe card.
Know your shutoffs
Every outcome on this card
WatchA clogged aerator or cartridge
A quick fix.
- Unscrew the aerator on the faucet tip
- Soak it in vinegar and rinse out debris
- If only hot water is weak, see the water heater cards
WatchA supply issue
Call the water utility.
- Check the utility’s outage page
- Report it
- Run cold water briefly once it is restored to clear sediment
TodayWater is going somewhere
Find the leak today.
- Walk the house: under sinks, the water heater, toilets, the yard line
- Close the main shutoff if you find active water
- Call a plumber if you can’t find it A slab or underground leak needs detection equipment.
This weekThe main valve or pressure regulator
Check the valve; plumber this week.
- Make sure the main shutoff is fully open Someone may have closed it partway.
- If you have a pressure regulator (a bell-shaped valve near the main), ask a plumber to test it
- Older galvanized pipes clog with rust over time A plumber can tell.
Related
Written from
- U.S. EPA WaterSense: Fix a Leak Week (finding leaks)
- Ready.gov (FEMA): Safety skills, know how to shut off utilities
Original casaq guidance, updated 2026-10-05. General guidance, not a diagnosis; licensed-pro review pending. Severity levels: Emergency now / Today / This week / This month / Watch. Send a correction.
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