Installing an expansion tank on a water heater is a relatively simple process and can be done by a DIY enthusiast or a professional plumber.
An expansion tank is installed on a water heater to prevent excessive pressure in the system caused by thermal expansion.
Installing an expansion tank on a water heater
Here are the steps to install an expansion tank on a water heater:
- Turn off the water and power supply to the water heater.
- Locate a suitable location near the water heater to mount the expansion tank.
- Install the tank support bracket to the wall or floor and secure it with screws or bolts.
- Mount the expansion tank on the support bracket and tighten any bolts or nuts to secure it in place.
- Connect the tank’s inlet and outlet fittings to the cold water supply line and hot water outlet pipe using Teflon tape and appropriate fittings.
- Fill the tank with air to the manufacturer’s recommended pressure.
- Turn the water and power supply back onto the water heater.
- Check for leaks at all connections and fittings.
- Monitor the pressure gauge on the expansion tank for proper pressure levels.
It’s recommended to consult the manufacturer’s instructions for specific installation details and requirements.

Tools needed
It is important to have all the necessary tools and materials on hand before starting the installation to ensure a smooth and successful installation process.
The tools needed for installing an expansion tank on a water heater typically include:
- Adjustable wrench or pliers: Used to tighten fittings and connections.
- Teflon tape: Used to seal threaded connections and prevent leaks.
- Screwdriver: Used to secure the tank support bracket to the wall or floor.
- Drill and drill bits: Used to make holes for mounting screws or bolts.
- Wall anchors or toggle bolts: Used to secure the tank support bracket to the wall if there are no studs available.
- Measuring tape: Used to measure and locate the correct placement for the expansion tank.
- Air pump or compressor: Used to fill the tank with air to the manufacturer’s recommended pressure.
- Pressure gauge: Used to monitor the pressure in the expansion tank.
- Hacksaw or metal cutting blade: Used to cut pipes if necessary.
DIY or hire a professional plumber
Whether to install an expansion tank on a water heater yourself or hire a professional plumber depends on several factors, including:
Skill level
If you are comfortable with basic plumbing and have experience with installation projects, you may be able to install an expansion tank yourself.
However, if you lack plumbing experience or are unsure about any aspect of the installation, it may be best to hire a professional plumber.
The complexity of the installation
If the water heater system is complex, has multiple components, or is in a difficult-to-reach location, it may be best to hire a professional plumber who has the expertise and equipment to handle the installation.
Tools and materials
If you do not have the necessary tools and materials to complete the installation, you may need to purchase them, adding to the overall cost of the project.
Time
Installing an expansion tank can be time-consuming, especially if you are not familiar with the process.
Hiring a professional plumber can save you time and ensure that the installation is done correctly.
Cost
Installing an expansion tank yourself can be more affordable than hiring a professional plumber, but the cost savings must be balanced against the risk of making mistakes or damaging the water heater system during the installation process.
In general, if you have the necessary skills and experience, installing an expansion tank on a water heater yourself can be a rewarding DIY project.
However, if you lack plumbing experience or are unsure about any aspect of the installation, it may be best to hire a professional plumber to ensure the installation is done correctly and the water heater system is protected.
Expansion tank for water heater
The expansion tank is an essential component of a water heater system.
A water heater is a crucial appliance in every household, providing hot water for showers, washing dishes, and laundry.
However, without proper maintenance, a water heater can experience problems caused by excessive pressure buildup, leading to leaks or even complete failure of the system.
This is where an expansion tank comes in.
An expansion tank is a small tank installed in a water heating system to accommodate the increased volume of water caused by thermal expansion.
Thermal expansion occurs when water is heated, causing it to expand and increase in volume.
In a closed system, such as a water heater, the increased volume of water can cause the pressure to rise to dangerous levels, leading to leaks, burst pipes, and even system failure.
The primary function of an expansion tank is to absorb the excess pressure and volume caused by thermal expansion.
This is done by installing a bladder or a diaphragm inside the tank that separates the air and water, allowing for the pressure to be absorbed by the air.
As the water expands, it pushes against the bladder or diaphragm, compressing the air and absorbing the excess pressure.
Installing an expansion tank is a relatively simple process and can be done by a DIY enthusiast or a professional plumber.
The first step is to locate a suitable location near the water heater to mount the tank. Next, the tank support bracket must be installed and secured to the wall or floor.
The expansion tank is then mounted on the support bracket and connected to the cold water supply line and hot water outlet pipe using Teflon tape and appropriate fittings.
The tank must be filled with air to the manufacturer’s recommended pressure, and the water and power supply to the water heater must be turned back on.
It is important to monitor the pressure gauge on the expansion tank for proper pressure levels and to check for leaks at all connections and fittings.
An expansion tank must be installed correctly to ensure that it functions properly and provides adequate protection to the water heater system.
In conclusion, an expansion tank is an essential component of a water heater system that helps prevent excessive pressure buildup and potential damage.
Installing an expansion tank is a simple and affordable way to protect your water heater and ensure that it provides hot water for your household for many years to come.
Choosing the best expansion tank to install on a water heater
When choosing the best expansion tank for a water heater, several factors should be considered, including:
- Size: The size of the expansion tank should be appropriate for the size of the water heater and the volume of water in the system.
- Capacity: The capacity of the expansion tank should be sufficient to accommodate the increased volume of water caused by thermal expansion.
- Material: Expansion tanks can be made from various materials, including steel, plastic, and composite materials. Steel tanks are durable and long-lasting, while plastic and composite tanks are lightweight and easy to install.
- Brand reputation: Choose a well-known and reputable brand with a good track record of producing high-quality expansion tanks.
- Price: Price is an important factor, but it should not be the only consideration when choosing an expansion tank. The price should be balanced against the quality and features of the tank.
Based on these factors, some of the best expansion tanks for water heaters include:
- Amtrol ST-12 Thermal Expansion Tank
- Watts DET-12 Domestic Hot Water Expansion Tank
- B&K 104-054 Expansion Tank
- SharkBite U3068FLEX24LF Water Heater Connector
- Bosch GT-10 Thermal Expansion Tank
The best expansion tank for a specific water heater system may vary, so it is recommended to consult with a plumbing professional or the water heater manufacturer for specific recommendations.
Amtrol ST-12 thermal expansion tank review

The Amtrol ST-12 Thermal Expansion Tank is a well-designed and durable solution for residential hot water heating systems.
This expansion tank helps to absorb the increased volume of water caused by thermal expansion, preventing damage to the water heater and other components of the system.
Here is a review of the Amtrol ST-12 Thermal Expansion Tank.
Design
The ST-12 has a compact design and is made from high-quality materials, making it a durable and long-lasting solution for hot water heating systems.
The tank has a pre-pressurized design, which makes it easy to install and maintain.
It features a simple design with a single connection for the water inlet and outlet, making it a popular choice for homeowners and contractors.
Installation
The ST-12 is easy to install and comes with detailed instructions.
The pre-pressurized design eliminates the need for a separate air pump or compressor, making the installation process quick and simple.
The compact size of the tank also allows it to be installed in tight spaces, making it a versatile solution for a variety of hot water heating systems.
Performance
The Amtrol ST-12 Thermal Expansion Tank is designed to absorb the increased volume of water caused by thermal expansion, preventing damage to the water heater and other components of the system.
The tank is designed to maintain the correct pressure in the hot water system, ensuring that the water heater operates at peak efficiency.
The ST-12 is also designed to be maintenance-free, making it a low-maintenance solution for hot water heating systems.
Cost
The Amtrol ST-12 Thermal Expansion Tank is an affordable solution for hot water heating systems.
The tank is competitively priced compared to other expansion tanks on the market, making it a cost-effective solution for homeowners and contractors.
The tank’s durability and long-lasting performance also make it a good investment for hot water heating systems.
Conclusion
The Amtrol ST-12 Thermal Expansion Tank is a high-quality and reliable solution for hot water heating systems.
Its compact design, easy installation, and durable performance make it a popular choice among homeowners and contractors.
The tank’s affordability and low-maintenance design make it a cost-effective solution for protecting hot water heating systems from the harmful effects of thermal expansion.