Low Water Pressure: 7 Common Causes in North Texas Homes

Low water pressure is one of the more frustrating plumbing problems because it affects everything — showers feel weak, filling a pot takes forever, and the dishwasher and washing machine run less effectively. The good news is that low pressure usually has a specific, identifiable cause. Here are the seven most common ones we encounter in Celina and surrounding North Texas communities.

1. Partially Closed Main Shutoff Valve

This is the first thing to check. Your main water shutoff valve — located where the water line enters your home or near the water meter — controls total flow into the property. If this valve was turned partially off during a repair and not fully re-opened, it restricts pressure to the entire house. The fix is simply opening the valve completely. Ball valves (lever style) should be fully parallel to the pipe when open. Gate valves (round wheel style) should be turned counterclockwise until they stop.

2. Failing Pressure-Reducing Valve (PRV)

Most North Texas homes have a pressure-reducing valve installed where the main water line enters. These valves reduce the pressure from the municipal supply (which can be very high — 80–100+ PSI) down to a safe level for household use, typically 45–65 PSI. When a PRV starts to fail, it can restrict pressure too much or fluctuate. A plumber can test your water pressure and adjust or replace the PRV if it's the cause of the problem.

3. Mineral Buildup Inside Pipes

In Celina and across North Texas, hard water is a real issue. The high mineral content — particularly calcium and magnesium — gradually deposits scale on the interior of pipes, slowly reducing their effective diameter. This is most common in older galvanized steel pipes, but it can affect any material over time. The water heater's supply connections and fixture supply lines are frequently affected first. If multiple fixtures have reduced flow and your home has older pipes, mineral buildup may be the cause.

4. Leaking Pipe Somewhere in the System

An active water leak — even a slow one — diverts water away from your fixtures and reduces pressure. Slab leaks (pipes leaking beneath the concrete foundation) are a common source of unexplained pressure loss in North Texas homes. Other signs of a hidden leak include unexpectedly high water bills, damp spots, or the sound of running water when no fixtures are in use. Professional leak detection can locate these without tearing up walls or floors unnecessarily.

5. Clogged Aerators and Showerheads

If the low pressure affects only one or two fixtures, the problem is likely at the fixture itself rather than in the supply system. Faucet aerators and showerheads accumulate mineral deposits over time, restricting flow. You can often unscrew an aerator and see the scale buildup directly. Soaking it in white vinegar dissolves the deposits. If this solves the problem, you've saved a service call. If it doesn't, the issue is upstream of the fixture.

6. Municipal Supply Issues

Occasionally, low pressure is coming from the water utility rather than anything inside your home. This can happen during periods of high demand, following a nearby main break, or during infrastructure maintenance. If neighbors are experiencing the same issue simultaneously, it's likely a supply-side problem. Contact your water utility to check for known issues in your area.

7. Water Heater Supply Valve

If the low pressure affects only hot water — not cold — the issue is between the water heater and your fixtures. Check that the shutoff valve on the cold water inlet at the top of your water heater is fully open. Also, heavy sediment buildup inside the tank can slow flow through the hot water outlet. A water heater that needs service is sometimes mistaken for a pressure problem rather than a heating problem.

How We Diagnose Low Pressure

When we're called for a low water pressure complaint, the first step is measuring actual water pressure at multiple points with a calibrated gauge. This tells us whether the problem is with the municipal supply, at the PRV, throughout the system, or isolated to one area. That measurement guides everything that comes next. If you're experiencing low pressure in your Celina area home or business, call us at +1 (972) 544-6460 for an accurate diagnosis.