water pipes and a pressure gauge with a graphic of an arrow transposed above the image

Water systems use the help of gravity to force water from a source or storage tank to the intended structure for use.

In addition, water pressure can vary and build up in your plumbing system, potentially becoming problematic when consistently high. 

Several factors can affect the water pressure within your home, which commonly increases during the night. Therefore, it’s essential to provide the inner workings of your structure with the proper maintenance and attention needed to prevent further issues. 

This article will explore why your water pressure increases overnight, including the common signs of high water pressure that can be hazardous for your home and wallet. 

Let’s get into it!

Why Does Water Pressure Increase Overnight?

Your water pressure increases overnight because your household typically uses less water during this time.

It could also be from not having a pressure-reducing valve or the one you have is not functioning correctly.

Home elevation and routine plumbing maintenance also play a role in water pressure.

a water pressure meter showing around 80psi with adjustment from a water pressure regulator on a house water line
I installed this pressure reducing valve on the city water inlet coming into our first netzero renovation house. The city water pressure was so high that there was a risk of actually bursting pipes in the house, and that would be a nightmare!

Most people go throughout their day not thinking of how their home systems work, like the water pressure and flow through the pipes, appliances, and fixtures. 

That is, until a difference is significant enough to catch your attention and make you wonder what’s happening.

For example, you usually notice a change in water pressure first thing in the morning when you turn the shower on or fill up your coffee pot.

Reasons Why Your Water Pressure Increases Overnight

There are several reasons for the pressure to vary, but the following are common reasons the water pressure increases overnight: 

  • Less water usage
  • Pressure-reducing valve (pressure regulator) issues or installation needed
  • Home elevation
  • System maintenance

Now that you know the main culprits, let’s look closer at each.

Less Water Usage

Gravity causes pressure in the water to build and become higher at night than during the day because there is less usage overnight.

So, the more water used in your household, the less pressure buildup you’ll have, and the more consistent your water pressure will be. 

However, if the pressure is too high or the overnight pressure increase is constant, you may need a professional to assess your pressure-reducing valve or install one.

Issues With Your Pressure-Reducing Valve 

Pressure-reducing valves, also called pressure regulators, control the water pressure within the home.

They prevent deucedly high pressure that can damage and cause issues to your plumbing system, fixtures, and appliances. 

Closeup on a water pressure-reducing valve with a gold cap
Courtesy of Watts

These valves wear down after long-term use and should be replaced every 7-10 years.

If the increased water pressure overnight is a sudden change, chances are your water pressure valve is no longer functioning as it should, and you should contact a professional.

If you lack a pressure-reducing valve, contact a professional because you may need to have one installed.

The Elevation of Your Home or Water Source

Water systems are designed for the supply tank to be at a higher elevation than the structure destination.

However, it’s not always the case when obtaining water from a municipal supplier because they supply water to many structures that vary in elevation

Your water pressure will significantly depend on your proximity to and elevation differential between the closest water storage tank and the supplier’s pressure setting. Municipal suppliers typically have the system set with enough pressure to reach all locations on the grid.

When your house is lower than the water supply, the water flow is also at the mercy of gravity.

Gravity helps the water reach its destination faster and begins causing pressure as it flows downhill and accumulates in your pipe system.

The closer you are to the elevation level of the water supply, the lower your pressure will be, and the lower your elevation in relation to the storage tank, the higher your water pressure will be.

Not Keeping Up With Your System Maintenance

The water pipe system will suffer buildup if you don’t perform routine maintenance. Debris, objects, and hard water minerals can create blockage or resistance in the water flow, resulting in inconsistent pressure. 

Staying on top of routine plumbing maintenance will help you identify issues before they become more pressing problems like pipes bursting from high pressure.

Closeup of a pipe that has sprung a leak and is causing water to spray out.

Plumbing maintenance entails some of the following: 

  • Checking for leaks around faucets, toilets, and piping, especially at elbows and seals
  • Listening for obstructions as the water is flowing through the pipes
  • Inspecting pipes for corrosion, damage, or moisture buildup
  • Keeping shower and faucet heads free of debris for easy water flow
  • Examining seals around fixtures and pipe connections for signs of breakdown
  • Using a pressure gauge to monitor your water pressure
  • Ensuring you know where the master shut-off valve is for the water in case of an emergency

While assessing for leaks and moisture on your pipes, remember that high humidity levels in your home can also contribute to condensation on your plumbing.

Wipe the moisture from the pipe and check later to see if there are beads of water, a condition indicating a slow leak.

As mentioned in our article, “What’s the Ideal Home Humidity for Comfort and Efficiency?” The humidity in your home should not exceed 50% for any season.

Constant condensation on pipes and fixtures can compromise and break down the plumbing materials.

Municipal Factors That Contribute to High Water Pressure at Night

Since municipalities play a crucial role in managing and distributing water to households, there are several factors that can contribute to increased water pressure overnight. They include:

Demand Fluctuations

Municipalities often experience variations in water demand throughout the day. 

The demand for water generally decreases at night as most businesses and industries shut down, and residents use less water. 

The reduced demand can lead to higher pressure in the water distribution system.

Pressure Regulation Systems

Municipal water supply systems are equipped with pressure regulation devices to maintain optimal pressure levels

When demand is low at night, these systems may regulate pressure to ensure that water reaches all areas of the distribution network adequately. 

However, if the regulation mechanisms are not finely tuned, it can result in higher pressure than necessary.

Pump Operations

Many municipalities use pumps to push water through the distribution system. 

The operation of these pumps is often controlled automatically based on demand patterns. 

During low-demand periods like at night, pumps may continue operating at a higher capacity, potentially causing an increase in water pressure.

Network Design and Infrastructure

The design and layout of the water distribution network can impact pressure levels. 

Pressure can build up if the network is not well-designed or if there are bottlenecks in certain areas. 

Municipalities need to regularly assess and maintain their infrastructure to ensure proper water pressure management.

Common Signs of High Water Pressure

High water pressure can damage your home’s plumbing system, appliances, faucets, and toilets.

If you suspect the water is building pressure overnight, you should invest in a pressure gauge to check the level.

A gauge is relatively inexpensive and can be found at your local hardware store. 

The water system in your home is designed to handle water pressure at 60 psi (pounds per square inch).

The higher the pressure, the higher the risk of damage to your pipes, appliances, and fixtures. 

Water pressure at a level close to 80 psi is too high for your plumbing system to handle. At this point, contacting a professional is recommended to fix the cause.

a man and woman working under the sink to fix the exposed plumbing pipes

The following are common signs of high water pressure in your household plumbing:

  • Sounds coming from your pipes like knocking and banging
  • Constant issues from appliances connected to the plumbing system
  • Excessive moisture buildup around pipe seals and joints
  • Leaks from faucets, toilets, and pipes
  • Faucets and shower heads make a “spitting” sound
  • A decreased lifespan of water heaters and appliances connected to the plumbing system


Constant high water pressure will severely stress your home plumbing system, leading to many other issues that can be pretty costly.

If you’re experiencing any signs of increased pressure, contact a professional to take care of your home plumbing.

You will commonly notice high water pressure in the morning because it’s built up overnight from not being used.

If it happens often, you may need a water pressure-reducing valve to prevent too much pressure from building.

Otherwise, you’ll eventually be pouring your hard-earned money down the drain from replacing damaged appliances, pipes, and hoses.

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