What Causes Too Much Pressure in a Hot Water Heater?

Your hot water heater provides heated water to the appliances and faucets in your home. Everyone wants to have a reliable source of hot water, whether it be for doing laundry, taking a shower, or cleaning dishes. 

However, water heaters are prone to pressure buildup. Without proper care and inspections, hot water heaters with too much pressure can leak or even explode. It is very important to make sure that you know what causes too much pressure in a hot water heater.

King’s Services are plumbing experts based in Winnipeg, MB. Our professionals will help you identify and solve your water heater issues. Give us a call at 204-633-9010 to talk to one of our technicians today.

How Water Heaters Work

Water heaters are insulated steel tanks that use electricity or gas to heat cold water. A heating element inside the tank warms up the cold water until it reaches a certain temperature.

Water heaters naturally produce some pressure. That is why they have pressure relief valves, or “P valves,” built in. P valves release excess pressure, preventing strain and damage to the water heater. 

Five Causes of Too Much Water Pressure in Hot Water Heaters

So what causes too much pressure in hot water heaters? Here are the top five reasons.

Mineral Deposits

Tap water contains minerals such as calcium and magnesium. Over time, these minerals build up inside hot water heater tanks, leading to pressure buildup. 

Routinely flush your water tank to eliminate any sediment buildup. Another option is to install a house-wide filter system for your water supply. These filtration systems lower the number of minerals present in your water.

Incorrect Temperature Settings

The thermostat is a key part of any hot water heater. When the temperature is set too high, internal pressure levels rise to a dangerous level. Temperature and pressure relief go hand in hand, so it is important to make sure that you set your thermostat at an appropriate level. Incorrect thermometer settings are often what cause too much pressure in a hot water heater.

Thermal Expansion

Thermal expansion occurs as the tank’s cold water heats up. The increase in temperature causes the water to gain volume, leading to a rise in pressure. Some degree of pressure increase is normal, which is why hot water heaters usually include expansion tanks. This tank gives the water space to expand without causing strain on the heater.

If your hot water heater does not have an expansion tank, or if it is too small, it may struggle to deal with increases in water pressure, putting more strain on the pressure relief valve. 

Water Supply Issues

Water supply issues can affect your hot water heater. If your local water system is not working properly and has too high pressure, then it can cause increases in pressure within your system. Water pipe leaks are also a frequent cause of pressure buildup.

Checking the pressure gauge mounted on the side of your water heater can help prevent water tank failure. If it is too high, try lowering the thermostat and then check your expansion tank to make sure that it is working properly. A malfunctioning expansion tank can cause too much pressure in a hot water heater.

Broken Heating Element

Heating element issues often cause pressure issues. All water heaters rely on either gas or electricity to heat up their water supply. 

Electric water heaters use a heating element, while gas water heaters use a high-limit switch. These pieces play a critical role in controlling water temperature within a tank. If they are not working properly, then the unit temperature may increase too much and cause pressure buildup.

Signs of High Water Heater Pressure

Knowing the signs of high pressure can help prevent problems before they arise. If you hear loud noises coming from your heater, or see it rattle back and forth, then you should adjust your water heater’s release valve. 

Brackish water, issues with consistent water heating, leakage around the tank itself, and strange hissing noises are other indicators of high pressure. You may also notice corrosion and rust on the outside of the tank. 

Address High Pressure in Your Water Heater Promptly

Ignoring the signs of high water heater pressure is dangerous, as it can lead to considerable damage and expensive repairs. High pressure can burst your pipes, causing water leaks and even flooding. It can also cause damage to the tank itself, harming the heating element and thermostat and preventing effective temperature regulation. 

Water leakage from excessive heater pressure can also cause your water bill to spike, costing you considerable money. Worst of all, water tanks experiencing extreme pressure levels can cause scalding or even catastrophic explosions, leading to serious injury or death. Learning what causes too much pressure in a hot water heater can save your life!

Proper Water Heater Maintenance

If your hot water heater seems to be experiencing high pressure levels, you need to act quickly and carefully to resolve the problem. Begin by turning off the heater’s power source, then look at the temperature and pressure relief valve on the tank’s side. If it is leaking or above 60 PSI (or what your water heater manual says is normal), there is too much pressure in the tank.

Turn off all appliances connected to the hot water supply, followed by the cold water supply valve. These steps should help release some of the pressure from your heater. Finish by adjusting your thermostat, ensuring it is set to around 120°F. 

Take time regularly to inspect your water pipes for leaks and flush out your water tank. Do not hesitate to seek professional help. Plumbers can help you learn what causes too much pressure in hot water heaters. You may also want to consider investing in a more energy-efficient water heater.

Water Heater Repair Services

If you hear water heater rattling, don’t hesitate to contact King’s Services. Our technicians help clients across the Winnipeg, MB, area solve their water heater troubles. Give us a call at 204-633-9010 today!