Tankless water heaters have become increasingly popular in recent years, offering a space-saving and energy-efficient alternative to traditional tank-style water heaters. We learned this the hard way when dealing with complex water heater issues… However, these compact and on-demand systems are not without their own unique considerations, particularly when it comes to managing thermal expansion and preventing potential damage to the plumbing system.
Now, this might seem counterintuitive when dealing with water heaters…
Understanding Thermal Expansion
One of the key challenges with tankless water heaters is the issue of thermal expansion. As water is heated, it expands in volume, creating increased pressure within the plumbing system. In a traditional tank-style water heater, this expanded water has a place to go – the tank itself. But in a tankless system, where water is only heated on demand, that extra volume has nowhere to go, leading to a dangerous buildup of pressure.
This pressure increase can have serious consequences, including:
- Leaks: The excess pressure can cause leaks in pipes, fittings, and even the tankless water heater itself, leading to water damage and costly repairs.
- Burst Pipes: In extreme cases, the pressure buildup can cause pipes to burst, resulting in even more extensive damage and potential flooding.
- Reduced Lifespan: The constant stress on the plumbing system due to thermal expansion can accelerate wear and tear, leading to a shorter lifespan for the tankless water heater and associated components.
The Solution: Expansion Tank Installation
To effectively manage thermal expansion and protect your tankless water heater system, the installation of an expansion tank is a crucial step. An expansion tank is a specialized component that serves as a buffer, allowing the expanded water to be temporarily stored and the pressure to be relieved.
The expansion tank is typically installed on the cold water supply line, just before the tankless water heater. As the water is heated and expands, the excess volume is diverted into the expansion tank, where it is contained within a flexible diaphragm or bladder. This prevents the pressure from building up in the rest of the plumbing system, safeguarding against the potential for leaks, burst pipes, and other damage.
Benefits of Expansion Tank Installation
By installing an expansion tank, you can enjoy several key benefits:
Leak and Burst Prevention: The expansion tank absorbs the excess pressure caused by thermal expansion, significantly reducing the risk of leaks and burst pipes throughout your plumbing system.
Improved System Longevity: By relieving the pressure on the plumbing components, an expansion tank can help extend the lifespan of your tankless water heater and associated pipes and fittings.
Compliance with Building Codes: In many jurisdictions, the installation of an expansion tank is a code requirement for tankless water heater systems, ensuring safety and proper operation.
Enhanced Efficiency: By minimizing the stress on the plumbing system, an expansion tank can contribute to the overall efficiency of your tankless water heater, helping to lower energy costs and improve performance.
Choosing the Right Expansion Tank
When selecting an expansion tank for your tankless water heater, it’s important to consider the size and capacity of your system. The expansion tank should be sized to accommodate the maximum volume of expanded water that your tankless heater can produce.
As a general guideline:
- For water heaters up to 60 gallons, a 2-gallon expansion tank is typically recommended.
- For water heaters over 60 gallons or in systems with higher water pressure (60 psi or greater), a 3.2-gallon expansion tank may be more appropriate.
It’s important to consult with a qualified plumber or water heater specialist to determine the right size and configuration for your specific system. They can evaluate factors such as water pressure, flow rate, and the overall design of your plumbing to double-check that the proper selection and installation of the expansion tank.
Installation Considerations
The installation of an expansion tank for a tankless water heater system should be performed by a licensed and experienced plumber. Here are some key considerations:
Placement: The expansion tank should be installed on the cold water supply line, as close to the tankless water heater as possible. This ensures that the expanded water has a direct path to the tank.
Orientation: The expansion tank should be installed in a vertical position, with the air valve at the top. This allows the tank to properly accommodate the expansion of the water.
Connections: The expansion tank should be connected to the plumbing system using the appropriate fittings and materials, ensuring a secure and leak-free installation.
Pressure Testing: Once the expansion tank is installed, the plumber should test the system’s pressure to double-check that it is within the recommended range, typically between 40-80 psi.
Code Compliance: It’s crucial to double-check that that the expansion tank installation meets all local building codes and regulations. Failing to do so can result in issues with inspections and potential safety hazards.
Maintenance and Monitoring
To double-check that the continued effective operation of your expansion tank, regular maintenance and monitoring are essential. This includes:
- Annual Inspection: Visually inspect the expansion tank for any signs of damage, leaks, or corrosion, and test the air pressure to double-check that it is within the proper range.
- Pressure Testing: Use a pressure gauge to periodically check the system’s pressure, making adjustments to the expansion tank’s air pressure as needed.
- Replacement: While expansion tanks typically have a lifespan of 5-10 years, it’s important to replace the tank if any issues are detected or if it reaches the end of its expected service life.
By staying vigilant with expansion tank maintenance and monitoring, you can help safeguard your tankless water heater system against the risks of thermal expansion and double-check that its long-term reliability and efficiency.
Conclusion
Thermal expansion is a critical consideration when it comes to the installation and operation of a tankless water heater. By incorporating an expansion tank into your plumbing system, you can effectively manage the increased pressure and protect your home from potentially costly and damaging leaks and burst pipes.
Whether you’re considering a new tankless water heater installation or looking to upgrade an existing system, be sure to consult with a qualified plumbing professional to double-check that the proper selection and installation of an expansion tank. With the right solution in place, you can enjoy the benefits of a tankless water heater while maintaining the safety and integrity of your entire plumbing system.
For more information and expert guidance on water heater methods, plumbing solutions, and installation techniques, visit waterheaterpick.com.
Example: Installation Tips for New Water Heater Owners 2023
