Low water pressure is one of the most common complaints we hear from homeowners in older Cobb County neighborhoods. East Cobb, parts of Marietta, and older sections of Smyrna and Kennesaw. The shower is a trickle. The washing machine takes forever to fill. Two faucets running at once cuts pressure in half.
The good news is that it's almost always fixable. The bad news is that a lot of homeowners try the wrong fixes first and waste time and money. Here's what's going on.
Symptom vs. cause.
"Low water pressure" is what you experience. The actual problem is almost always one of five things. Diagnosing which one matters because the fix is different for each.
Before you do anything else, do this 30-second test: turn on a single fixture (cold water only) and watch the flow. Now turn on a second fixture in the house. Did pressure drop noticeably? That single test points to where the problem is.
The five real causes.
Galvanized pipe corrosion
The #1 cause of whole-house low pressure in older Cobb County homes. Until the mid-1960s, homes were plumbed with galvanized steel pipes. They corrode from the inside, building up rust and scale that gradually shrinks the pipe diameter. A 3/4 inch pipe might end up with the equivalent of a 1/4 inch hole after 50 years. The real fix: partial or whole-house repipe.
Failed or misadjusted pressure regulator
If your home has a pressure regulator (PRV) on the main supply line, it can fail or drift over time. A failing PRV often shows up as low pressure throughout the house. The real fix: replace the PRV. Lifespan is typically 7 to 12 years.
Hidden leak
A significant leak somewhere in your system reduces the pressure available at your fixtures. Higher water bill plus dropping pressure? Check the water meter with everything off. If the dial moves, you have a leak. The real fix: find and repair the leak with professional detection equipment.
Municipal supply issues
Sometimes the problem is upstream of your house. Low pressure at outdoor hose bibs (which bypass interior plumbing) and neighbors with similar complaints point to a municipal issue. The real fix: a booster pump.
Fixture-level issues
If only one fixture has poor pressure, the problem is local. Clogged aerator, scaled showerhead, failing supply valve, cracked supply hose. The real fix: usually a five-minute aerator clean or an inexpensive part swap.
How to diagnose.
A quick walkthrough to figure out where the problem is:
- Test your pressure with a gauge. An inexpensive gauge that screws onto a hose bib will tell you your static pressure. Normal is 45 to 75 PSI.
- Check single vs. multiple fixtures. If pressure drops when two are running, your supply lines are restricted.
- Check hot vs. cold separately. If hot is much worse, that points to galvanized pipes or sediment in the water heater.
- Look at fixture age and pattern. One bad fixture is probably local. All bad is system-wide.
- Check your water bill for unexplained spikes.
Don't repipe a whole house unless you have verified that's the problem
We've been called in to second-opinion full repipes that turned out to need a new pressure regulator. Always rule out the simple fixes first.
Real, lasting fixes.
Once you know the cause, the fix becomes clear:
- Galvanized pipe corrosion: Repipe with copper or PEX. Modern installs restore full pressure for decades.
- PRV failure: Replace the regulator.
- Hidden leak: Locate and repair.
- Low municipal pressure: Install a booster pump.
- Fixture issue: Clean or replace the aerator, showerhead, valve, or supply line.
A pressure problem is a diagnosis problem. Get the diagnosis right and the fix is easy.
If you're dealing with chronic low pressure in your Cobb County home, give us a call. We diagnose the real cause and tell you the most cost-effective way to fix it. 770-439-0919 or request a free estimate online.
