Water Heater

What Causes Too Much Pressure In The Hot Water Heater

What Causes Too Much Pressure In The Hot Water Heater

Water heaters are an important part of a home. From dish washing to showering, they play an important role. But have you ever faced a pressure build-up issue of a water heater? If so, then you might be wondering what causes too much pressure in the hot water heater. It could be any reason, like mineral deposits or an issue with the temperature controller. To know about it in detail, read on.

Problems With Water Heater Pressure:

Now let’s talk about problems with pressure that can happen in hot water heaters. There are several things that can cause these systems to have high pressure.

Steam Build Up:

The main reason for too much pressure in the water heater is the buildup of gas or vapor. If minerals or sludge in the tank block the heat exchanger, the steam won’t be able to make air or steam. If the pressure inside the tank gets too high, it could blow up or at least rupture. The pressure on your hot water heater may be pretty high if your home doesn’t get enough fresh air.

Mineral Deposits:

The presence of magnesium and calcium in tap water might cause the hot water tank’s pressure to rise and efficiency to drop.

Frequent tank flushing prevents this by clearing out silt and mineral accumulation. This keeps everything running smoothly and stops pressure from building up in your tank. You can reduce the amount of salt in your water supply by installing a whole-house water filtration system.

Controllers of Temperature:

Improperly adjusted tank thermostat settings can also cause over-pressurization of a hot water tank. Putting a tank at temperatures exceeding 120 degrees Fahrenheit could cause the pressure inside to rise. Leaks and other problems do arise, as was mentioned before.

Adjusting the thermostat by adjusting the temperature inside your home never rises above 120 degrees Fahrenheit.

Water Heater Malfunction:

There are a number of potential reasons why water heater pressure would rise. Upper and lower elements are used in most water heaters. All of the thermostats for the various heating elements talk to one another. The upper thermostat is the “boss,” and when the temperature hits 180 degrees Fahrenheit, it flips a high-limit switch. The electricity is cut off when the water heater’s high-limit switch is activated.

The power is restored when you press the reset button on a thermostat. If the high-limit switch on your water heater trips again, you should have it serviced.

No Expansion Tank:

As water heats, its volume increases owing to thermal expansion, increasing the pressure within storage tanks and plumbing. A tank’s pressure can be reduced by using an expansion tank to drain any surplus water. Closed plumbing systems necessitate the installation of expansion tanks. Closed systems ensure that water used for household plumbing never enters the public water supply.

Also, Read: Does An Electric Water Heater Have A Pilot light?

High-pressure Symptoms:

The following are symptoms of high pressure:

Discoloration of water:

Over pressurization in the water heater can cause cloudy water. Discolored water could be a sign of high pressure in your water heater.


Think back on how your water heater usually sounds. If your water heater is making popping or hissing noises, the pressure inside may be too high.

Exhibit Signage:

Check out your hot water heater. If your water heater has rust spots or pools of water, you should have it checked out. If you ignore a Leaking hot water heater, it could flood your home.

Also, Read: What Are The Disadvantages Of A Heat Pump Water Heater?

What Happens When You Have a High Water Pressure?

Did you know most home plumbing systems can’t handle water pressure above 80 psi? Some reasons to question your home’s high water pressure:

Damage Pipes:

A home’s water supply could have a surprising force. Often, we suffer long-term consequences without even realizing it. Minor leaks can develop in pipes subjected to high water pressure cycling over time. Although these cracks might not look like much initially, they can lead to serious problems, including pipe bursts and structural damage.

Damage Water Heater:

This expands when heated. Most water heaters require thermal expansion tanks to manage increased water flow. Consistently high water pressure over 80 psi might cause damage to your water heater as it expands to meet the demands of the water.

Fixtures And Appliance Deterioration:

Without adequate water pressure, dishwashers, washing machines, and other water-using appliances can’t function properly. When water pressure is too high, appliances wear out faster and must be replaced more often. There will be more dripping sinks, toilets, and showers, even if you haven’t showered in a while.

Water heaters have safety features to prevent dangerous pressure buildup inside the tank. Sometimes, these safeguards are compromised or fail to work as intended. They could be lost for all we know.

What Prevents Pressure From Increasing?

All tank-style water heaters must include a temperature and pressure relief valve or T and v valve (T&P valve).

The building code requires that you install a pipe along the side of your water heater’s tank.

When the internal tank temperature or pressure reaches 210 degrees Fahrenheit or 150 pounds per square inch, the T&P valve releases pressure. The release of pressure causes the valve to seal. The T&P valve may have been opened due to high tank pressure if there are puddles around your tank.

If the problem persists, you should talk to an expert about finding the cause.

T&P valves, like any other valve, require routine maintenance and testing to ensure proper operation. Valve corrosion is facilitated by sediment and limescale. It could help to flush the system or replace the valve.

Switch With A High Limit:

The high-limit switch activates when the temperature in the tank reaches 180 degrees Fahrenheit. When the switch is activated, the water heater will cut off power.

Your water heater probably has a problem that must be fixed if you constantly push the reset button. Hire an expert to assist you with plumbing repairs if necessary.

Heater Explosion:

Although it is rare, water heaters can burst. Keep your T&P valve and water heater in good working order.


A hot water heater can occasionally experience dangerously elevated pressure levels. You must recognize the root causes of this problem and take preventative or corrective action for your hot water heater’s safety, effectiveness, and lifespan.


How can the pressure in the water heater be reduced?

Typically, bolts, locking nuts, and screws are used with regulators. With a wrench, loosen the locking nut, then use a screwdriver to turn the screw counter-clockwise (left) or clockwise (right) to change the water pressure.

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About the author

Mobeen Shahid

Mobeen Shahid is a Mechanical Engineer with two years of experience in the HVAC industry. His passion is analyzing HVAC issues, and he works relentlessly to devise customized solutions. He has been in the industry long enough to know the ins and outs and ensures that areas are optimally heated, cooled, and ventilated.