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Why Is My Water Pressure Low Throughout the House?
Low water pressure in the house usually means the problem is upstream of your faucets, such as a partly closed main or meter valve, failing pressure reducing valve (PRV), corroded pipes, hidden leak, or municipal supply issue. If just one faucet has weak pressure, the problem is more likely a clogged aerator or cartridge rather than a whole-house issue.
Is It the Whole House or Just One Fixture?
If both hot and cold water have weak pressure at several fixtures, you are probably dealing with a whole-house water pressure problem rather than a single clogged faucet.
Turn on several faucets and showers throughout the house and compare the flow. Check both hot and cold water because weak hot water alone can point toward the water heater or hot-water piping instead of the main supply.
If only one faucet or shower is weak, start with its aerator, showerhead, or cartridge. If every fixture is affected, move upstream and look at the home's water supply.
What Causes Low Water Pressure Throughout the House?
Common causes of whole-house low water pressure include partially closed supply valves, a failing PRV, corroded pipes, hidden leaks, municipal supply problems, and clogged water-treatment equipment.
| Likely cause | What's happening | What to do |
|---|---|---|
| Partly closed main / meter valve | Supply valve isn't fully open | Open the main & meter valves fully (DIY) |
| Failing pressure reducing valve (PRV) | The regulator is stuck or worn | Have a plumber test/replace the PRV |
| Corroded or old pipes | Galvanized pipes narrow with buildup | Ask a plumber about repiping |
| Hidden leak | Water escaping before it reaches taps | Call a plumber for leak detection |
| Municipal / utility issue | Low supply or nearby water-main work | Check with neighbors and your utility |
| Water softener / filter clog | A clogged softener or filter restricts flow | Bypass/replace the filter; service the softener |
A sudden pressure change can narrow down the possibilities. Slow loss of pressure over several years is more consistent with deteriorating pipes or another gradually developing restriction.
What Can You Check Yourself?
Homeowners can safely check the main shutoff valve, water meter valve, neighborhood water supply, visible signs of leaks, and water-treatment equipment before calling a plumber.
- Check the main shutoff valve. Make sure it is fully open, particularly if plumbing work was recently completed.
- Check the water meter valve. If the water meter valve is readily accessible and intended for homeowner operation, confirm that it is fully open. If it is utility-controlled, sealed, or unfamiliar, contact the water utility or a plumber rather than attempting to adjust it.
- Ask your neighbors. If nearby homes have the same problem, the municipal water supply or water-main work may be responsible.
- Look and listen for leaks. Wet areas, unexplained running-water sounds, or an unusual increase in water use can indicate a hidden leak.
- Check water-treatment equipment. If possible, according to the equipment instructions, bypass the water softener or inspect the whole-house filter to see whether pressure improves.
Do not attempt to adjust, repair, or replace the PRV or household piping unless you are qualified to do so.
Can a Pressure Reducing Valve or Old Pipes Cause Low Pressure?
A failing pressure reducing valve and restricted galvanized pipes are two possible whole-house pressure problems that require diagnosis by a licensed plumber.
The pressure reducing valve (PRV) regulates higher incoming municipal pressure before water enters the home's plumbing. When the regulator wears out or sticks, it can reduce pressure too far and leave every faucet and shower with weak flow.
Older galvanized pipes develop internal corrosion and mineral buildup that gradually reduce the opening available for water. When deterioration affects large portions of the plumbing system, repiping may be needed instead of repairing one isolated section.
GAC's plumbing repair team can test household pressure, inspect the PRV, and determine whether the restriction involves a valve, pipe, or incoming water line.
Why Did My Water Pressure Drop Suddenly?
A sudden whole-house pressure drop can point to a failed PRV, leaking or burst pipe, water-main problem, or utility work affecting the local supply.
Ask nearby neighbors whether their pressure changed at the same time. If several homes are affected, contact the local water utility for information about outages, maintenance, or a water main problem.
If only your home is affected, look for wet spots, unexplained running-water sounds, or other signs of a leak. A sudden pressure loss combined with evidence of escaping water needs prompt professional attention.
A gradual decline is different. It is more consistent with slowly developing pipe corrosion, a restrictive filter or softener, or a PRV that is deteriorating over time.
When Should You Call GAC Services?
Call GAC Services when whole-house water pressure remains low after basic checks or when you suspect a failed PRV, hidden leak, restricted piping, or another plumbing problem.
GAC's licensed plumbers serve Gaithersburg and communities throughout Montgomery, Frederick, and Howard Counties, including Rockville, Silver Spring, Germantown, Frederick, Bethesda, and Potomac. The team offers 24/7 availability, free estimates, and upfront pricing.
GAC provides plumbing services for pressure problems as well as broader piping and water-system concerns. Homeowners dealing with scale, sediment, or treatment-equipment issues can ask about water quality testing & treatment.
Schedule Online (240) 224-0192Frequently Asked Questions
Check several fixtures and ask nearby neighbors about their water pressure. If multiple homes have the same problem, the municipal supply or water-main work may be responsible. If only your house is affected, the cause is more likely somewhere in your home's supply or plumbing system.
Yes. A failing PRV can become stuck or worn and reduce incoming pressure too far. A licensed plumber can measure the home's pressure, test the regulator, and replace it when necessary.
A water softener can restrict flow if it becomes clogged, is improperly sized, or needs service. If the manufacturer’s instructions provide a homeowner-safe bypass procedure, temporarily bypassing the unit may help identify whether it is contributing to the pressure problem. Otherwise, have the system checked by a plumber or water-treatment professional.
Sudden low pressure can result from a failed PRV, hidden or burst pipe, water-main problem, or utility work. Check with neighbors first, then look for signs of a leak if the problem appears limited to your property.
First identify why the pressure is low rather than simply trying to raise it. The solution may involve fully opening a supply valve, servicing a clogged filter or softener, replacing a failed PRV, repairing a leak, or addressing restricted piping. A plumber can measure the pressure and determine the correct repair.
