Low Water Pressure: Causes and Fixes

A sudden drop in water pressure at every faucet indicates the problem lies in your main lines. You might be dealing with a broken pressure reducing valve or a significant leak somewhere in the house.\n\nIf the issue is isolated to one sink, the malfunction is likely local. Check aerators and cartridges for mineral buildup, which is a common culprit. For major repairs like repiping or heater replacement, hire a licensed plumber, who will handle any required permits.

Decoding the Cause of Low Pressure

If you notice low water pressure only at a specific fixture like a shower or a bathroom sink, the source of the blockage is likely close to that point of use. You should first inspect the aerator on the faucet or the showerhead for mineral buildup. These screens can become clogged with sediment over time, acting like a restrictive filter. If you remove a small screen and see dark debris or calcium deposits, a simple soak in vinegar often fixes the issue. However, if the low pressure affects your entire home, the problem sits deeper in the supply lines, often requiring professional diagnosis.

Fixing Aerators and Valves

Cleaning the aerator is a simple repair that usually does not require a call to a professional. Unscrew the tip of the faucet to access the mesh screen. If you have plastic grips, do not use pliers, as this can damage the finish. Soaking the screen in vinegar for several hours dissolves hard water deposits and debris. If you have a single-handle cartridge in the valve stem, remove the handle and the bonnet nut to view the valve seat. This component often faces issues where mineral pieces jam the mechanism. Replacing the cartridge is a common fixture repair that restores water volume at a fraction of the cost of a whole-house fix.

Checking the Pressure Regulator

You must also consider the pressure reducing valve if you experience consistent issues throughout the house. This device is located on the main water line near the meter and regulates incoming pressure from the street. If the internal spring weakens or the seals fail inside the valve, the pressure drops, and your water flow suffers. You cannot effectively fix or adjust this component with DIY tools alone. You need a licensed plumber to verify the valve and determine if it is the bottleneck. Similarly, a drop in municipal water pressure from the city or an issue with the service main could be the cause, requiring a licensed technician to inspect the supply connection.

Water Pipe Damage and Corrosion

If your home was built before the 1980s and has not been repiped, the pipes may be made of galvanized steel. Over decades, these pipes rust from the inside out, creating thick layers of scale that significantly restrict flow. This deterioration occurs gradually until there is barely enough space left for water to pass. A professional plumber can run a pressure gradient test to confirm if the inside diameter is critical. Note that replacing plumbing in older homes is a major job that often involves permits and inspections, so it is important to hire an RMP licensed plumber for the safety and code compliance of your home.

Well Systems and Pressure Tanks

Acreage properties that rely on a private well require a different approach to troubleshooting. These systems use a bladder tank to maintain water pressure. If the bladder inside the tank has failed or the air cushion has leaked out, the pump will run constantly without building pressure. You might hear the pump humming constantly without water coming out of the tap. Sometimes, you can bleed air into the tank to relieve the pressure momentarily, but the leak will return quickly. A licensed plumber can replace the tank or adjust the pump switch settings to ensure the system does not burn out and provide consistent flow for your home.

Frequently asked questions