Pressure relief valves, also known as “P valves,” are critical safety devices found in hot water heaters. These valves are designed to release excess pressure that builds up in the tank, preventing dangerous situations and potential damage to the water heater and surrounding areas.
But what causes too much pressure to build up in a hot water heater in the first place? In this article, we will explore the various causes of excessive water pressure in hot water heaters and how to address them.
Contents
How to know what causes too much pressure in hot water heater
In this part, we will discuss what causes too much pressure, and give a detailed description of each possible cause.
Thermal expansion
One of the most common causes of too much pressure in a water heater is thermal expansion. As the water heats up in the tank, it expands and increases in volume. This can cause the pressure to rise within the closed plumbing system of the water heater.
To mitigate this, most hot water heaters are equipped with an expansion tank, which is connected to the water heater and allows for the expansion of the water without putting pressure on the system.
However, if the expansion tank is not properly sized or maintained, it may not be able to handle the excessive water pressure, and the relief valve will open to release the pressure.
The water heater is a closed system
Another cause of too much pressure in a hot water heater is a closed system. In an isolated system, the water heater is not connected to a municipal water supply, and the pressure within the system is not regulated by a pressure relief valve.
Instead, the pressure within the system is determined by the pressure of the incoming cold water, which can be much higher than in a municipal water system. This high pressure can cause the relief valve to open, releasing excess pressure.
Malfunctioning heating element
Excess water heater pressure can also be caused by a malfunctioning heating element in an electric water heater or a high-limit switch in a gas water heater.
These components regulate the temperature of the water in the tank, but if they malfunction, the temperature can become too high and cause the pressure to rise.
Problem with the water supply
Another potential cause of too much pressure in a water heater is a problem with the water supply.
If the municipal water system has excessively high pressure, this can cause the pressure within the water heater to rise as well.
Additionally, if there is a leak in the water pipes leading to the water heater, this can cause water to enter the tank at a faster rate than it can be heated, leading to a pressure increase.
To prevent and address too much pressure in a hot water heater, it’s important to regularly check the pressure gauge and ensure that the temperature setting is not too high.
If the pressure rises too much, the relief valve will open, releasing hot water and potentially causing damage to the surrounding area.
It’s also important to maintain the expansion tank and ensure that it is properly sized for the hot water tank.
In addition, if you have an isolated system, consider installing a pressure-relief valve to regulate the pressure within the system.
How to identify if there is too much pressure in your water heater
There are a few ways to determine if there is too much pressure in a water heater.
One common symptom is if the temperature rises rapidly or the hot water runs out quickly. This can be caused by a malfunctioning heating element or a problem with the water heater’s power supply.
Another sign of excessive water pressure is if the water heater’s temperature and pressure relief valve is leaking or discharging water. This valve is designed to release pressure if it gets too high to prevent the tank from bursting.
Another way to check for too much pressure in tank-style water heaters is to check the water pressure at the nearest faucet. A reading of over 60 psi (pounds per square inch) is considered too high and can cause damage to the water heater and other plumbing fixtures.
If you suspect that your water heater has too much pressure, it’s important to address the issue as soon as possible to prevent damage to the water heater or other parts of your plumbing system.
You can try to reduce the pressure by adjusting the pressure-relief valve or by releasing pressure through the temperature and pressure-relief valve.
If you’re unsure how to do this or if the problem persists, it’s best to call a plumber to diagnose and fix the issue.
How to check the pressure in your water heater step-by-step
Checking the water pressure in your home is an important step in maintaining the proper functioning of your water heater and other appliances that use water.
Excessive water pressure can cause damage to the heating element and other components, leading to potential leaks or even failure of the unit.
Step 1
First, locate the pressure release valve on your water heater. This is typically located near the top of the tank and is a small valve with a lever or button that can be pressed to release pressure.
Step 2
Next, you will need a pressure gauge. These can be purchased at most hardware stores.
Step 3
Attach the pressure gauge to the pressure release valve by unscrewing the valve’s cover and screwing the gauge onto the valve stem.
Step 4
Turn on the water heater’s power supply, and wait for the temperature to rise.
Step 5
Check the pressure gauge reading. The pressure should be between 12 and 15 psi (pounds per square inch) for most water heaters.
If the reading is higher than this, it may indicate excessive water pressure.
Step 6
Causes of too much pressure in a water heater include a malfunctioning pressure-relief valve, a closed or partially closed shutoff valve, or a problem with the municipal water supply.
Step 7
A high-limit switch is a safety device that will shut off the power to the water heater if the water pressure becomes too high.
Step 8
If the pressure in the tank becomes too high, the relief valve will open, and the water will be released to prevent the tank from bursting.
Step 9
Another cause of high pressure could be an expansion tank, which allows water to expand as it is heated, preventing the pressure from becoming too high.
Step 10
If the pressure gauge reading indicates excessive water pressure, it’s important to have a professional plumber check and fix the issue to prevent damage to the unit.
Frequently asked questions
How do you reduce the pressure on a water heater?
To reduce the pressure on a water heater, you can adjust the pressure-relief valve or install the expansion tanks. A pressure-relief valve controls the amount of water pressure entering the home and can be adjusted to lower the pressure.
Why is my water heater pressure so high?
There are several reasons why water heater pressure may be high. It could be due to a malfunctioning pressure-relief valve, a closed or partially closed shutoff valve, or a problem with the local water supply.
What would cause water pressure to increase?
Water pressure may increase due to a problem with the local water supply, a closed or partially closed shutoff valve, or a malfunctioning pressure-relief valve.
Why does my water heater keep releasing pressure?
A water heater releases pressure through the relief valve when the pressure inside the tank becomes too high. This is a safety feature to prevent the tank from bursting. The relief valve opens, and the water will be released to reduce the pressure.
If the relief valve is opening regularly, it could be an indication of a malfunctioning pressure-relief valve, a closed or partially closed shutoff valve, or a problem with the local water supply.
Conclusion
In summary, too much pressure in a hot water heater can be caused by a variety of factors, including thermal expansion, an isolated system, malfunctioning heating elements or high-limit switches, and problems with the water supply.
Regular maintenance and monitoring of the pressure gauge, temperature setting, and expansion tank can help prevent excessive pressure and ensure the safety and longevity of your hot water heater.
Additionally, in the case of an isolated system, installing a pressure-reducing valve can help regulate the pressure within the system and avoid excessive pressure. With proper care and attention, you can enjoy hot showers and the convenience of having water on demand, without the fear of too much pressure in your water heater.
Read also: Removing baseboard heaters: Do it by yourself!
