Turning on the faucet and realizing there’s no water pressure in the house can be frustrating, especially when it happens without warning. The truth is, sudden pressure changes are common, and the causes for low water pressure in homes aren’t always serious.
In Hill Country homes, house low water pressure is often tied to simple issues like temporary city water work, mineral buildup, or a failing valve. Understanding what typically causes a sudden drop can help you stay calm, rule out minor problems, and know when it’s time to call a professional.
Why Is My Water Pressure Low All of a Sudden?
The causes for low water pressure in homes generally fall into a few categories, including city supply changes, fixture blockages, and in-home plumbing components that wear out over time.
1. City Water Maintenance or Hydrant Flushing
One of the most common causes of sudden low water pressure is work on the municipal water system. Routine maintenance, line repairs, or fire hydrant flushing can temporarily reduce pressure across an entire neighborhood.
How this usually shows up:
- Pressure drops at all fixtures
- Neighbors may notice the same issue
- Pressure often returns within a few hours
Sediment stirred up during city work can also clog faucet aerators, making the problem seem worse than it is.
2. A Partially Closed Main Water Shutoff Valve
If the main shutoff valve to your home isn’t fully open, water pressure can drop quickly and without warning. This valve can be accidentally bumped during yard work, inspections, or other home projects.
What to watch for:
- Weak pressure throughout the home
- No other obvious plumbing problems
- Sudden change after recent work around the meter or foundation
Even a slightly closed valve can significantly restrict flow.
3. Clogged Faucet Aerators or Showerheads
In areas with hard water, mineral buildup or sediment can clog fixtures almost instantly, especially after city water work.
Typical signs:
- Low pressure at one faucet or shower
- Normal pressure elsewhere
- Issue appears suddenly
This is one of the most common reasons homeowners experience low water pressure in certain areas of the house.
4. A Clogged Whole-House Water Filter
If your home uses a whole-house water filter, a clogged cartridge can restrict water flow to every fixture at once.
This is likely if:
- Pressure drops throughout the home
- Filters haven’t been changed recently
- The issue appeared all at once
Whole-house filters are helpful, but they need regular replacement to avoid pressure problems.
5. Water Softener Problems
Water softeners are common in Hill Country homes due to hard water. When a softener malfunctions or becomes restricted, it can cause sudden low water pressure.
Common indicators:
- Pressure fluctuates or drops unexpectedly
- No visible leaks
- Problem affects hot and cold water
Softener issues often require professional service to restore proper flow.
6. A Failing Pressure-Reducing Valve (PRV)
A pressure-reducing valve controls how much water pressure enters your home. When it begins to fail, pressure can drop suddenly throughout the house.
Signs of PRV trouble include:
- Whole-home low water pressure
- No improvement over time
- Pressure changes without warning
PRVs wear out over time and typically need replacement rather than adjustment.
7. Hidden Plumbing Leaks
A hidden water leak can reduce available water pressure while increasing water usage behind the scenes.
Red flags to watch for:
- Sudden pressure loss plus a higher water bill
- Damp spots on walls, ceilings, or floors
- Wet soil near the foundation
Hidden leaks should be addressed quickly to prevent structural damage and costly repairs.
When to Call a 72 Degrees Texas Plumber
If your water pressure is low in the house suddenly and:
- The problem affects every fixture
- Pressure doesn’t return after a few hours
- You notice signs of leaks or water damage
…it’s time to have a licensed plumber take a look.
At 72 Degrees Air Conditioning, Heating, and Plumbing, we’ve helped homeowners across Fredericksburg, Kerrville, and the surrounding Hill Country restore steady water pressure since 1986. Our experienced plumbers in Kerrville will identify the cause, explain what’s happening in plain language, and fix the problem the right way.
