Why Is My Water Pressure Suddenly Low?

Sudden drops in water pressure are usually caused by something inside your home, like a partly closed valve, a clogged aerator, or a failing pressure-reducing valve, though the water utility can sometimes be the source. Most causes are easy for a plumber to track down, and a few you can check yourself in just a few minutes. 

Symptoms 

• Water trickles instead of flowing normally from one or more faucets 
• Showers feel weak or take longer to rinse off soap and shampoo 
• The change happened suddenly, not gradually over months 
• Pressure is low at only one fixture, or at every fixture in the house 
• Pressure drops noticeably when more than one fixture runs at the same time 

Causes 

• A partially closed shutoff valve, either the main valve or one under a sink or toilet 
• A clogged faucet aerator or showerhead from mineral buildup 
• A clogged or corroded pipe, especially in older homes with galvanized steel plumbing 
• A failing pressure-reducing valve (PRV), the device that controls how much pressure enters your home from the main line 
• A hidden leak, which can pull pressure away from the rest of the house 
• A problem with the water utility’s main line or your water meter 
• A weakening well pump, for homes on well water 

DIY vs. Pro 

What you can check yourself 

• Figure out if the problem is at one fixture or the whole house 
• Unscrew and rinse out the aerator on the affected faucet 
• Confirm the main shutoff valve is fully open 
• Ask a neighbor if they are having the same issue, which points to a utility problem instead of your plumbing 

When to call a plumber 

• Pressure is low throughout the entire house 
• You suspect a hidden leak, such as a wet spot, a higher water bill, or the sound of running water 
• The pressure-reducing valve needs adjustment or replacement 
• Your pipes are older galvanized steel and may be corroded 
• The DIY checks above did not fix the problem 

Tech tip: if pressure drops at only one fixture, it is almost always a local clog you can clear yourself. If it drops throughout the entire house at the same time, a plumber will usually check the pressure-reducing valve first, since that single part controls pressure for every fixture in the home. 

Seasonal Considerations 

Cold snaps can cause pipes to constrict, and in unheated areas, freezing and thawing can create small leaks that show up as a pressure drop once the weather warms back up. Hot, dry summers increase demand on municipal water systems, which can cause brief pressure dips during peak-use hours. In homes with older galvanized pipes, corrosion builds up gradually and often becomes more noticeable as the seasons change and hot and cold water use shifts. 

FAQ 

Q: Is low water pressure always a plumbing problem in my house? 

A: Not always. Sometimes it is caused by the water utility working on the main line nearby, or by high demand in your neighborhood. If pressure is low throughout your whole house and your neighbors have normal pressure, the issue is more likely inside your home. 

Q: Can I fix low water pressure myself? 

A: Some causes, like a clogged aerator or a partly closed shutoff valve, are simple fixes. Others, like a failing pressure-reducing valve or a hidden leak, need a licensed plumber. 

Q: What is a pressure-reducing valve? 

A: It is a device installed where the main water line enters your home that controls how much pressure reaches your pipes and fixtures. When it wears out or gets stuck, pressure throughout the house can drop or spike. 

Q: How do I know if I have a hidden leak? 

A: Watch for a higher-than-usual water bill, damp spots on floors or walls, or the sound of running water when nothing is turned on. A plumber can also test for leaks directly. 

Q: Will my water pressure ever go back to normal on its own? 

A: If the drop is caused by utility work, pressure often returns once the work is finished. If the cause is inside your home, like a clog or a failing valve, it typically will not improve without a repair. 

If your water pressure dropped suddenly and a quick check of the aerator and shutoff valve did not help, Golden Rule Plumbing, Heating, Cooling & Electric can find the cause and fix it for good. Contact our team today to schedule a plumbing visit.