Why is water pressure low in my whole house?
Weak flow at every tap, showers that lose force when another fixture runs, and appliances that take much longer to fill.
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Key takeaways
- This is usually not an emergency, but it does not fix itself and it gets worse if you leave it.
- Most likely cause: Failing pressure reducing valve.
- Do this first: Confirm the main shutoff and the meter valve are fully open.
- Call right away if pressure disappeared suddenly and water is surfacing in the yard or basement.
- The repair starts with: Measure static pressure at an outside hose bibb.
What it is
Low water pressure throughout the house Whole house low water pressure means every fixture runs weaker than normal, which points to a system wide cause such as a partially closed main valve, a failing pressure regulator, or scale buildup inside the supply piping.
It is a comfort and equipment issue rather than an emergency, but a bad pressure regulator can also let pressure spike and damage appliances if left unaddressed.
The short answer
When pressure drops at every fixture at once, the cause is upstream of the house plumbing. The usual suspects are a failing pressure reducing valve, a partly closed main shutoff, corroded galvanized supply piping, or a leak in the buried water line between the meter and the house. Utility work in the street can also drop pressure temporarily. If pressure fell suddenly and the yard is wet or the meter spins with everything off, treat it as a service line leak.
What it usually means
These are the causes we find most often, ranked from most likely to least.
- 1
Failing pressure reducing valve
Most likely
The valve that regulates incoming city pressure fails closed over time and starves the house.
- 2
Main shutoff or meter valve not fully open
Common
Often left partly closed after other plumbing work.
- 3
Corroded or scaled supply piping
Common
Older galvanized lines narrow from the inside until flow drops across the whole house.
- 4
Leak in the buried water service line
Less common
Pressure escapes before it reaches the house. Often paired with a rising water bill.
- 5
Municipal supply issue or nearby main work
Occasional
Temporary and affects neighbors too. Worth a quick check before any repair.
What to do right now
- 1Confirm the main shutoff and the meter valve are fully open.
- 2Ask a neighbor whether their pressure dropped too.
- 3Turn everything off and watch the meter. Movement means a leak somewhere on your side.
- 4Check whether hot only, cold only, or both are weak. Hot only points at the water heater.
When it is an emergency
- Pressure disappeared suddenly and water is surfacing in the yard or basement.
- You have no water at all rather than weak water.
What the fix involves
The repair follows the diagnosis. A failed pressure reducing valve gets replaced and the house pressure is set back into a safe range. Corroded supply piping is repiped in the affected runs. A leaking service line is located first, then repaired or replaced.
- 1Measure static pressure at an outside hose bibb.
- 2Test the pressure reducing valve and main shutoff.
- 3Isolate house piping from the service line to find the restriction.
- 4Replace the valve, repipe the restricted runs, or repair the service line.
What drives the cost
Every job is quoted before work begins. These are the factors that move the number on this kind of repair.
- Valve replacement versus repiping versus service line work
- Depth and length of a buried water line repair
- Access through finished walls, ceilings, or concrete
- Permits and restoration where excavation is required
Related problems homeowners ask about
Why is water pressure low at just one faucet?
One tap or shower runs weak while every other fixture in the house is normal.
Read this nextWhy do I have no water at all?
Every tap in the house is dry, or the first taps give a short burst of air and then nothing.
Read this nextWhy did my water bill suddenly go up?
A bill well above the seasonal norm with no change in usage, sometimes with a warm floor spot, a damp yard, or the sound of running water.
Read this next
Read more on this
This page is for triage and dispatch. These guides go deeper on how the work is done and what shapes the price.
Licenses, credentials, and company proof
- Colorado Master PlumberLicense MP-18927
- Colorado State Plumbing ContractorLicense 2110
- Family Owned & OperatedServing Denver since 2006, 20 years
- Better Business BureauAccredited Business, A+ rating
- Angie's List Super Service Award2012 through 2017
- Serving Denver since 2006Residential and commercial properties across the metro
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Before you book: pricing, timing, and guarantees
Straight answers on what low water pressure whole house work costs, how fast we can get out, and what stands behind the repair.
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