What causes a drop in water pressure in your house?

Low water pressure is a frequent problem in many houses. There are multiple things that can cause water pressure issues in your home. An experienced plumber knows exactly what to look for and how to treat the problem most efficiently.

Pipe Material and Fittings Matters

The first thing that St Paul Pipeworks plumbers check when they identify low water pressure is whether you have older, galvanized steel threaded water pipes in your home. Galvanized steel will react with copper and brass pipes and fittings.

Even if you do not have any copper piping in your house, you will have brass because most valves and faucets are made of brass. The galvanized threaded steel pipes react with the lesser metals and will start to plug up and deteriorate.

The plumber will see the beginning of a rust spot on the surface of the pipe as the deterioration is working its way through the metal. Suspended in most water are particles, chiefly iron and calcium, that do not affect our health but do adhere to each other and to the insides of the pipes causing eventual plug-ups.

It may take twenty years or more for that to happen, but it will eventually plug up. The effective inside diameter of the pipe will get smaller and smaller, which negatively affects your water pressure.

What is the water pressure from the city?

Another thing an experienced plumber checks is the incoming water pressure level from the city. Those pressures can vary from low pressure to high pressure around each municipality. The ideal water pressure in a house is between 40 pounds per square inch (PSI) and 60 PSI.

A plumber can measure that by using a gauge. If the water pressure is too low, St Paul Pipeworks can often overcome this lack of delivery by increasing the inside diameter of the pipes.

They will remove the old pipes and install new ones, ensuring the piping is the correct sizing to attain the best water pressure possible for your home. When areas of the city where the pressure delivery is very poor or under 40 PSI, St Paul Pipeworks sometimes will install an oversized main.

The re-pipe and pipe replacement help to overcome the delivery from the city. Occasionally there can be a problem where the pressure level is too high, and a pressure-reducing device can be installed. If the water pressure is over 80 PSI, the Plumbing Code in Minnesota requires it to be brought back down to 80 PSI or below.

Is Plugged Plumbing Causing Reduced Water Pressure?

Sometimes low water pressure is simply a matter of a plug-up. There are service calls where a plumber will go out and find that a kitchen sink is not delivering very much pressure. The plumber will then ask if this is also happening in the bathroom sink, and the customer will reply, “No, I think the bathroom is fine.”

The plumber will look at the kitchen faucet and remove and clean the aerator, then work backward until they find the plug. It can get plugged up at the aerator, or it can get plugged up if the water supply tubes are too small. Sometimes the whole faucet must be taken apart to clean out excess debris or replace the inner parts of the fixture to restore the water pressure.

Not All Water Pressure Is Equal

Various levels of your home may also have differing levels of water pressure. The water pressure dramatically reduces the higher that it is pushed up. As you look at your house, you likely will find the best water pressure in the basement. The second-best pressure will be on the main floor, the third-best pressure will be on the second floor, and so forth.

In each story of a house, you will lose half of a PSI or around 5 PSI lost for each level of the house. Your plumber will take that into account when they are doing a re-pipe.

If you are having a problem with low water pressure in your home or are just looking for a quality plumber in the St. Paul and Minneapolis metro area, give St Paul Pipeworks a call today.

Yours Truly,

Matthew Dettwiler

Social Media Manager


Q: What are the common causes of low water pressure in a house?

Answer: Lower than normal water pressure can stem from various issues. One common cause is aging galvanized steel threaded water pipes, which react with metals like copper and brass, leading to deterioration and eventual blockages. Mineral deposits such as iron and calcium can also accumulate in pipes over time, reducing the effective inside diameter and causing low pressure.

Q: How can I determine if my home’s water pressure is low?

Answer: A plumber can measure your water pressure using a gauge. Ideal pressure ranges between 40 to 60 pounds per square inch (PSI). If the pressure is too low, it might require replacing pipes to increase the diameter for better pressure. Conversely, high pressure above 80 PSI may necessitate installing a pressure-reducing device to comply with plumbing codes.

Q: What steps can St Paul Pipeworks take to address water pressure issues?

Answer: St Paul Pipeworks has solutions tailored to specific problems. For low city water pressure, they might replace pipes or install larger mains. In cases of localized blockages, they’ll inspect faucets and fixtures, cleaning or replacing parts as needed to restore proper water flow.

Q: Is low water pressure consistent throughout a home?

Answer: Typically, water pressure varies among different levels of a house. Basements often have the best pressure, while higher levels experience reduced pressure. For each story, about half a PSI or around 5 PSI might be lost, a factor that St Paul Pipeworks considers during re-piping projects.

Q: How can I resolve low water pressure issues in my home?

Answer: If you’re experiencing reduced water pressure or seek reliable plumbing services in the St. Paul and Minneapolis metro area, contact St Paul Pipeworks. Their experienced plumbers can diagnose issues accurately and offer tailored solutions to restore optimal water pressure in your home.

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