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Low Water Pressure: Why Does It Happen & What to Do About It

Low Water Pressure

Low water pressure in one or more faucets in your home can mean trouble. Not only does it affect your livelihood by not being able to use running water as intended, but low water pressure may also indicate a host of underlying problems. 

If the sudden low water pressure in the house is left untreated, everyday activities like taking a shower or doing laundry get disrupted, hindering your normal functioning. In most cases, the problem will not go away on its own, and you need to look into the issue right away. 

It helps to understand the potential causes of low water pressure in your house. These can range from severe rust buildup in the pipes to defective pressure regulator to malfunctioning water meter valves. The cause of the problem can also be external, such as a low water table in your town’s municipal system or something else.

Keep reading to find out how to solve low water pressure in the house and where to go to for help.

Low Water Pressure in House: Underlying Causes

Water regulating systems and plumbing fixtures are fine-tuned systems with many components that need to be in good repair and often inspected for that reason. First, you need to establish whether your water supply comes from a single source, which helps narrow down the problem. 

If you are relying on a ground well, another area you must consider is the water pump inside the well. Otherwise, several components on your premises can cause low water pressure.

Main Valve 

Over time valves can get eroded or damaged. A faulty valve can open or shut on its own. If your house has low water pressure, try opening up the valve. If this is the problem, water pressure will pick up almost immediately, but you will still need to replace the main valve as the problem will only persist. 

Water Pressure Regulator

The water pressure regulator is the key component for regulating how much water enters your house from the main water supply. Too much pressure means potential problems; too little, and you’ll get a trickle of water in your faucets. 

The regulator controls the pressure level within a safe zone before water from the main enters the plumbing in your premises, including appliances requiring water. A faulty regulator can cause either sudden low water pressure in the house or high water pressure. 

This is one of the first things you need to check with an adequate pressure gauge, and the reading should ideally be between 55 and under 80 psi. The average life span of a good pressure regulator is around 15 years, so it is wise to write down the date of the last repair job near the part. 

Old Water Pipes

If the plumbing in your house is copper or galvanized steel and has been running some mileage, there is a high likelihood of corrosion buildup inside the pipes. If the buildup is severe, the water flow is slowed down and may be further compounded by leaky or malfunctioning valves and regulators. 

Old plumbing needs to be replaced sooner than later as this impacts the water quality. Left unchecked, corroded pipes will start to leak, if they already aren’t, and cause flooding and other damage. You can definitely not fix this yourself, so calling a professional should be the first order of business. 


Mineral deposits, dirt and rust, can reduce water flow or completely clog your faucets. If you get a trickle of water and the problem is not with the water main or with the valves, you need to flush or unclog your fixtures.

If your water local supply has a hard pH value of 8 or above, you will likely see the holes on your shower head or faucets clogged.

There are various solutions against gunk and mineral buildup. If your showerhead permits a trickle of water, you can unscrew the head and place it in a plastic container filled with vinegar or a store-bought solution.

Another way to do the job yourself is to unscrew the aerator part at the top of the spout. Often, you will find sand and even pebbles that reduce water flow. 

External Factors for Low Water Pressure in House

If your home is in an area that is prone to flooding or droughts, low water pressure in house can be attributed to either. Flood areas suffer from clogged drainage, and debris can enter the city’s plumbing, which can reflect on your water supply. Likewise, low water tables due to drought will impact how much water you are getting from your tap. 

Whether your supply comes from the municipal system or your own ground well, a lack of rainwater over the years will impact underground aquifers. In the event, call your municipal water works or a water/plumbing professional to consult on how you can improve the water pressure in your home.

Another important thing that needs to be checked is a change in local government regulation. As a response to lower water tables or increased water usage, your municipality may be pressured to regulate, that is, decrease the water output going into households. If this is the case, the municipality will inform its residents, so make sure to check whether this has been the case for your town. 

How to Fix Low Water Pressure in House: Step-by-Step Instructions

As a resident, you can try to investigate the problem yourself. You can take a few steps to find out how to fix low water pressure. However, be advised to perform these tests carefully and only if you have the technical skills for the task, such as fixing a pressure gauge. 

  • Call your neighbors to see if the water pressure is low on their premises too. If this is the case, the problem should be investigated by your municipal water works for burst pipes, clogs, leaks or other problems. 
  • Check all water fixtures in your home. If the issue persists in one fixture, say a shower head, but the remaining faucets are working fine, the problem may be located in that specific part. 
  • Turn on the cold water tap first on multiple fixtures and try to see if there is a difference between them. Then stop the cold tap and turn on the hot water. If the hot tap has low pressure, there may be a fault with the boiler. 
  • Check the water main valve, as rust buildup can cause the valve to turn, or it could be that someone tightened the valve. You can turn the valve wide up to see if the low water pressure in your house improves.  
  • Check for water pressure yourself. If you can perform this bit, you can connect a water pressure gauge to the fixture on the nearest valve. If the reading is below 45 psi, there is a problem with the pressure-reducing valve, or it has been tightened a bit too much. 
  • Are there two sources of water supply in your home? Primary and secondary? Do you have a water well and your own pressure tank? If so, make sure you check both if you know which water fixtures or appliances are connected to what system.

Sudden Low Water Pressure in House: A Sign to Call the Experts

Opinions on normal water pressure (psi) for residential homes vary between experts. Some claim 30 psi is enough, while others claim 45 is the minimum threshold that your water fixtures and appliances, like the dishwasher and laundry machine, require to operate normally. 

The high limit for water pressure is between 65 and 80 psi. Municipal waterworks have a code determining the maximums, which is usually 80 psi. If the water pressure in your home is too high, it can cause leakage, burst pipes, and disrupt or break your appliances.

Tampering with the plumbing can cause a more severe disruption in your water supply, resulting in higher costs and potential damage to your flooring, furniture and appliances. If you are wondering why is the water pressure low in my house, you’ll get the best advice from experts in your area. 

Installing a Water Pressure Booster

If you are impacted by persistent low water pressure that’s outside your control, a professional may advise you to install a water pump. These pumps are installed on the main line before its entry point into the building. If the problem concerns a larger home or commercial premises, you will find a fitting solution in a water pump booster which can get water to higher verticals. 

How to Fix Low Water Pressure in House: Conclusion

As a resident of a house with sudden low water pressure, there are steps that you can take to investigate the problem on your own. However, calling a professional will give you the best insight as to what causes the problem and how to fix low water pressure in the house. This problem cannot be left untreated as it may uncover serious damages in your plumbing, pressure regulator, valves or all of the above. 

Calling Cummings Plumbing in Tucson is your safest move to determine the problem and get  the best solution. 


Can a water heater cause low water pressure?

Water heaters can suffer from various problems over time, including hard water mineralization and sediment buildup. Both clog vents and pipes, resulting in loss of output. Other reasons are a tightened valve, an electric issue, inadequate pipe width or too many bends before the water reaches the fixture. 

Why is my water pressure low when I have two faucets?

We can point out several potential issues causing low pressure when water is running from two faucets: shut-off valves, main water valve, aerator screens, water heater, rusty plumbing, etc. 

How much does it cost to replace a house water pressure regulator?

The cost of labor for replacing a pressure-reducing valve can range between $300 and $500. Professional plumbers charge more for providing service on weekends, holidays or late at night. Hard-to-access valves incur bigger costs. A good valve is between $50 and $100. 

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