Causes of Low Water Pressure In House & The 10 Best Cures

Balkan University
November 7, 2023

by David Balkan

A clogged and corroded galvanized plumbing fitting.

Decreased or low water pressure in house conditions can be caused by various factors. It can also happen gradually, or suddenly as wel. Instead of concentrating on the causes, let’s exlpore and provide you with a list of the 10 most common cures.

Some cures for low water pressure in a house are relatively simple and quick, while others will require the skills of a knowledgeable tradesperson, or a licensed plumber. One key is being self-aware of your skill level, the tools required, and the extent of the work required. With that being said, what follows is a helpful and enlightening top 10 list.

Low water pressure in house caused by clogged lead water line.
Old lead water service line clogged with corrosion and sediment

A Top 10 List of Cures for Low Water Pressure in House

1. One of the simplest and easiest cures for a localized low water pressure in house issue is to remove and clean out all sink faucet strainers. The same can be said for shower heads, as mold and sediment can build uop in shpwer heads as well. Debris, sediment, and even mold growth can clog your plumbing outlets. These cure takes minutes, requires no special tools, and requires a low skill level.

2. If you’re suffering with low pressure in house, or a section of your house, the simplest thing to do is to make sure all of your water valves are fully opened. First check your main control valve on the house side of your water service line. The work your way back through your entire plumbing system.

Of course, if the low water pressure issue is localized, check the control valve for that section of your plumbing first. Always remember that no matter the size of type of water valve, never use brute force to make it turn.

3. In rare cases low water pressure in house conditions must be cured by replacing the water service line from the house to the connection on the public water main. A full water service line replacement would be required only under certain circumstances. Those circumstances would include if your water service line ruptured, is filled with corrosion, or is too small to properly service the needs of the plumbing fixtures in the building. Whenever you must repalxce your water service line, it’s vitally important that the water line be sized out properly by your plumbing contractor.

In some cases the tap connection, the connection from the city water main to your service line, may be clogged or undersized. In most cases this condition would alos require excavation work.

4. Deciding whether to replace a section of the inside piping, or a whole house re-pipe is a big decision as a cure. This cure must be carefully determined before undertaking any work. In some cases there may be a small section of galvanized, or undersized pipe. In those cases a relatively minor plumbing repair can be done.

However in other cases, such as a home being plumbing entirely in galvanized pipe, the entire system may be restricted by corrosion and rust. The buildup of mineral deposits, rust, or debris inside water pipes can restrict the flow of water and decrease pressure. It’s always important to determine if this condition is local to one or two fixtures, or to the entire house.

Low water pressur Low water pressure in house caused by corroded galvanized fitting
Just one corroded galvanized fitting can ruin your home’s water pressure

5. As stated above, over time pipes can corrode. However, if you water pipes are copper or brass, no matter how old they get, the inside of the pipes should never fill with corrosion and become restricted. An easy way to determine if this is even a possible low water pressure in house condition cause is to check the plumbing material by using a magnet. Only galvanized pipe is magnetic, a magnet will not stick to copper or brass plumbing.

6. In rare cases an ill-adjusted water pressure regulator must be readjusted to correct a water pressure issue. Only a small percentage of building shave such a device, and it is advisable us to a licensed plumber to deal with this device. A malfunctioning or incorrectly adjusted water pressure regulator will cause a drop in water pressure throughout the house.

7. In some cases (as stated above) the plumbing may be undersized. You would know that if by using multiple water fixtures or appliances, such as showers, a washing machine or a dishwasher simultaneously temporarily lowers your water pressure. No plumbing system is designed to allow this to happen – it is not normal! All properly designed plumbing systems are designed to allow for multiple plumbing fixtures to operate properly simultaneously. In these cases it’s up to you to decide whether to live with the low water pressure in house issue, or upgrade the section of your water pipes in question.

Low water pressure in house caused by an undersized tap connection on the city water main.
Old and new tap connections on a NYC water main

8. Sometimes a drop in your home’s water pressure is completely unrelated to you or your plumbing system. This brings up another potential easy cure for low water pressure in house, is to call 311 (or the equivalent number in your area). If you local water authority (in NYC it’s the NYC DEP) is doing work in the area, either a repair or an upgrade, they may have shut your water off. In some cases it may be partial shutdown, where your pressure will be lower, but not eliminated.

A way to eliminate a potential issue after their work is done is to close your main water supply valve. This will lessen the chance of, amount of sediment and rust, entering into your home plumbing. After the DEP has completed their work, open a faucet on an upper floor, and remove the sink strainer. Then very slowly reopen your main valve. Be careful to allow all the air inside of your pipes to escape, and for any sediment and debris to run out of your faucet as well.

9. In some cases, if lower pressure pertains to your hot water exclusively, the cure may be to replace components inside the hot water heater, or the hot water itself. This is another case where the cure for low water pressure in house must be determined as either systemwide, localized, or a component.

10. In some cases (virtually never in NYC) the cure for low water pressure involves the pump for a well water system. In NYC wells are not permitted as a source of drinking water. Some folks in NYC do have wells and pumps, but they are intended for use in irrigation, watering landscaping, etc. In these cases the cure for low pressure would certainly to be to contact a professional familiar with wells and pumps.

A Conclusion About Low Water Pressure In House Cures

It should be become readily apparent that it’s most important to identify the specific cause and cure of decreased or low water pressure in house issues is a sensible step-by-step assesment, and then the appropriate first step as a cure. Depending on your assesment (as stated above) the cure may simple and DIY, or plumbing repairs may be needed. Another great bit of advise to never to rush into a hiring decision, and to always consult a professional plumber when the issue is above your knowledge or skill level. Never forget that your drinking water supply is a vital and required resource, and not something that can be contaminated or handled improperly.

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David Balkan

David Balkan is the CEO of Balkan Sewer And Water Main, the largest and most trusted service in New York City. David is extremely active in various NYC plumber organizations being the Chairman of the Subsurface Committee in the Master Plumbers Council, and Vice President of the Subsurface Plumbers Association. In addition David’s expertise is respected by officials of New York City agencies such as the NYC DEP, NYC DOB, and the NYC DOT. He frequently provides valuable input on a variety of industry related matters.

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