Low water pressure can make everyday tasks like showering, washing dishes, and doing laundry frustrating. If you’re wondering, “Why is my water pressure low?” the problem may come from mineral buildup, a failing pressure-reducing valve, a partially closed shutoff valve, plumbing leaks, or aging pipes.
Our team has decades of local plumbing expertise in Utah homes, and we know how hard water can affect your water pressure. Here’s what causes low water pressure, what you can safely check yourself, and when the problem requires professional attention.
What “Normal” Water Pressure Actually Means for Your Home
Water pressure measures the force that moves water through your home’s plumbing in pounds per square inch (PSI).
The typical residential water pressure range varies depending on your plumbing system, fixtures, elevation, and other factors. However, plumbing codes generally limit household water pressure to 80 PSI unless you have a pressure-reducing valve.
If your water pressure is low, you can get a basic reading with a pressure gauge. Attach the gauge to an outdoor hose bib, make sure faucets and water-using appliances are off, and open the hose bib fully.
How Salt Lake City’s Municipal Water Supply Affects Your Home Pressure
Municipal water pressure can vary based on factors such as location, elevation, and conditions within the local water distribution system.
If several nearby homes experience a similar pressure change, the Salt Lake City Department of Public Utilities handles all municipal water service or pressure concerns.
The 6 Most Common Reasons Why Your Water Pressure Is Low
Trying to identify the reasons why your water pressure is low? Here are six common reasons why your water pressure may be off and what to look for.
1. Mineral Buildup From Hard Water
Hard water contains dissolved minerals such as calcium and magnesium. Over time, mineral deposits can accumulate in faucet aerators and showerheads and restrict the path water uses to reach the fixture.
What to look for: Check for whitish or yellowish mineral deposits around faucet aerators or showerhead openings. Removing an aerator may also reveal deposits inside it.
What you can do: Clean or soak a mineral-clogged aerator or showerhead according to the fixture manufacturer’s instructions. If cleaning the fixture does not improve the flow, the plumbing should be professionally evaluated.
2. A Partially Closed Shutoff Valve
A partially closed main shutoff valve can restrict the amount of water entering your plumbing system. This sometimes happens when a valve is not completely reopened after plumbing work.
What to look for: If the pressure dropped shortly after a repair or other plumbing work, check your home’s accessible main shutoff valve.
What you can do: Confirm that the homeowner-accessible shutoff valve is fully open. Do not attempt to operate utility-owned valves at the water meter. If you suspect the problem is on the utility side, contact the water provider or a plumber.
3. A Water Leak in Your Supply Line
A plumbing leak can reduce the amount of water reaching your fixtures. Depending on its location and severity, a hidden leak may contribute to a noticeable drop in pressure throughout the home.
What to look for: Low pressure combined with unexplained increases in water usage, damp areas, or other signs of escaping water warrants further investigation.
What you can do: Avoid digging into walls or underground plumbing to find the problem yourself. Professional water leak detection can help locate a hidden leak and determine the appropriate repair before additional water damage occurs.
4. Corroded or Galvanized Steel Pipes
Older plumbing systems may contain galvanized steel pipes that corrode internally over time. As corrosion and deposits build up inside the pipe, the opening becomes narrower and can restrict water flow.
What to look for: Low pressure paired with brown or rust-tinted water can point to corrosion. This is especially true when the discoloration appears after a faucet has not been used for a while.
What you can do: Internal pipe corrosion is not a fixture-level DIY repair. A plumber can inspect the system to determine whether deteriorating or restricted pipes are contributing to the problem and whether sections need to be replaced.
5. A Failing Water Pressure Regulator (PRV)
A pressure-reducing valve, also called a water pressure regulator, reduces high incoming water pressure before water moves through your home’s plumbing. Plumbing codes call for a PRV when static pressure exceeds 80 PSI.
If the regulator becomes obstructed or stops working correctly, you may notice low or fluctuating pressure throughout the house.. PRV problems are generally best handled by a qualified plumber.
What to look for: Check whether several fixtures have the same pressure problem rather than just one faucet or shower.
What you can do: A plumber should diagnose and replace a faulty PRV. Working on this component requires shutting off the home’s main water supply, and an improper repair can result in leaks or water damage.
6. Peak Demand Hours From Shared Municipal Supply
If you’re wondering, “Why is my house water pressure low?” the answer may be outside your home. Incoming pressure can be affected by temporary changes in the municipal water distribution system.
What to look for: Pressure that changes at certain times or a similar pressure problem affecting nearby homes can indicate that the issue is not limited to your plumbing.
What you can do: If you suspect a municipal issue, contact the Salt Lake City Department of Public Utilities for information about your water service.
Low Pressure in Just One Fixture vs. the Whole House — How to Tell the Difference
Wondering, “Why is my water pressure low?” Start by determining whether it’s a whole-house issue or a single-fixture problem.
| Low Pressure Throughout the House | Low Pressure at One Fixture |
|---|---|
| The main shutoff valve is partially closed | The faucet aerator is clogged |
| The pressure regulator is malfunctioning | The showerhead has mineral buildup |
| The supply line has a leak | The fixture shutoff valve is partially closed |
| Pipes are corroded or restricted | The faucet or shower cartridge has a problem |
| Municipal supply conditions are affecting incoming pressure | Individual fixtures need repair |
When Only One Faucet or Shower Has Low Pressure
If every other fixture works normally, the problem is usually located at the affected faucet or shower. A clogged aerator, mineral buildup, partially closed fixture shutoff valve, or worn cartridge may restrict flow.
For low water pressure in the shower, start by checking and cleaning the showerhead. If removing mineral deposits does not improve the flow, the shower valve or cartridge may need professional inspection.
When Every Fixture in the House Has Low Pressure
When pressure is weak throughout the home, look beyond individual fixtures. A partially closed main shutoff, faulty PRV, supply line leak, restricted piping, or an issue affecting the incoming municipal supply may be responsible.
Check several fixtures in different parts of the house. If all have weak flow, confirm that your accessible main shutoff valve is fully open.
When to Call a Plumber — and What to Expect
If you keep asking, “Why is my home water pressure low?” it may be time for a professional diagnosis.
Call a plumber if you notice:
- A sudden whole-house pressure drop: A main-line leak, pressure regulator problem, or another system-wide issue may be responsible.
- Higher water usage with low pressure: An unexplained increase in water use may indicate a hidden leak.
- Discolored water and low pressure: Corroded or deteriorating pipes may be restricting water flow.
- Gradually declining pressure: Mineral buildup, corrosion, or another restriction may be developing within your plumbing.
- Low pressure after basic checks: If cleaning affected fixtures and checking the main shutoff does not help, further testing may be needed.
What a Plumber Will Do During a Pressure Diagnostic Visit
A plumber can help you answer, “Why is my water pressure low?” They’ll start by measuring your home’s water pressure. Then, inspect the pressure regulator and accessible shutoff valves and check for signs of leaks, corrosion, or plumbing restrictions.
A plumber may also suggest a water filtration or water softener system to help reduce future hard water problems that lead to low water pressure.
Get Professional Help With Low Water Pressure
If you’re experiencing low pressure when you shower, wash your hands, or do laundry, you may be wondering, “Why is my water pressure low?” Just Right Plumbing, Heating, & Cooling can help walk you through what causes low water pressure and recommend the right solution for your home.
Our residential plumbing services help restore reliable water flow and comfort for you and your family.
Low Water Pressure FAQs
What PSI is considered low water pressure in a house?
There is not one ideal PSI for every home, but consistently weak flow at multiple fixtures can indicate a pressure problem. You can check your home’s pressure by attaching a pressure gauge to an outdoor hose bib while faucets and water-using appliances are turned off.
Can hard water cause low water pressure?
Yes, hard water can contribute to low water pressure when mineral deposits build up and restrict water flow. Cleaning scale from faucet aerators and showerheads may solve a fixture-level problem, while restrictions deeper inside the plumbing should be evaluated by a plumber.
Why is my water pressure low only in the shower?
Low water pressure in a shower is often caused by mineral buildup or a clogged showerhead. If cleaning the showerhead does not restore normal flow, the problem may involve the shower valve, cartridge, or another fixture component that needs professional attention.
Why did my water pressure suddenly drop?
A sudden whole-house pressure drop can indicate a failing pressure-reducing valve, plumbing leak, or main shutoff valve that was not fully reopened after recent work. Check your home’s accessible shutoff valve first. If pressure remains low, have a plumber diagnose the problem.
Does the city of Salt Lake City control my home’s water pressure?
Salt Lake City Public Utilities operates the municipal water distribution system. Components on or within your property can also affect the pressure you experience at fixtures. If multiple nearby homes have similar pressure problems or you suspect a municipal issue, contact the Salt Lake City Department of Public Utilities.
