Short answer
Low pressure at one fixture is usually a clogged aerator, cartridge or supply valve. Low pressure throughout the house usually comes from a partly closed main valve, a failing pressure regulator, corroded galvanized pipe, a leak, or a utility-side issue.
One fixture
- Unscrew and clean the aerator
- Check the shutoff valves under the sink are fully open
- Hot side only? The water heater or its valve may be the cause
Whole house
- Confirm the main valve is fully open
- Ask neighbors if they're affected (utility issue)
- A failing pressure-reducing valve can drop pressure suddenly
- Galvanized pipe narrows from internal rust over decades
- A hidden leak steals pressure; do the meter test
Checks you can do in ten minutes
Readings below about 40 psi feel weak, and readings above 80 psi are too high and can damage fixtures.
- Unscrew the aerator on the weak faucet and rinse out any grit
- Check whether the problem is hot only, cold only or both
- Make sure the main shutoff and the valve at the water heater are fully open
- Buy a hose-bib pressure gauge and test at an outdoor faucet with everything else off
- Ask neighbors whether their pressure dropped too; that points to the utility
Causes a plumber has to fix
- Galvanized supply pipe narrowed by internal rust
- A failing pressure-reducing valve near the main
- A hidden leak in the service line or under the house
- Sediment or scale in older water heaters affecting the hot side
- Undersized piping after additions or remodels
When to call a plumber
If the steps above don't solve it, or anything involves sewage, gas, electricity near water or a leak you can't stop, call a licensed plumber. Related help: pipe repair in Gastonia, leak detection in Gastonia, water line repair in Gastonia.
Where this comes up most in Gaston County: Willow Creek, York-Chester, Loray Mill Village, Downtown Gastonia, Forest Heights, Highland, Belmont, NC, Mount Holly, NC. See all Gastonia and Gaston County service areas.
Frequently asked questions
Can a leak cause low water pressure?
Yes. A significant supply leak diverts flow. If the meter moves with everything off, look for a leak.
Do older Gastonia homes have low pressure from galvanized pipe?
Homes built before the 1960s often had galvanized supply pipe, which rusts internally and restricts flow over time.
Editorial note: this guide gives general safety and maintenance information for homeowners. It doesn't replace an on-site diagnosis by a licensed plumber. Codes and permit rules can change; check with your local inspections office.