An expansion tank may be small, but it plays an important role in protecting a home's plumbing system and water heater from pressure created by thermal expansion. As water heats, it expands. In a closed plumbing system, that additional volume needs somewhere to go.
Marc Francis Plumbing provides expansion tank installation, replacement and evaluation in Johnson City and throughout the surrounding Tri-Cities area. With more than 40 years of hands-on plumbing experience, Marc can evaluate the water heater, incoming water pressure, pressure reducing valve (PRV) and expansion tank as parts of the overall plumbing system rather than treating each component separately.
What Does a Water Heater Expansion Tank Do?
When water inside a water heater is heated, it expands. In an open plumbing system, some of that expanded water may be able to move back toward the public water supply. In a closed system, devices such as a pressure reducing valve or backflow prevention device can prevent that pressure from moving backward.
A properly sized and installed thermal expansion tank provides a place for the expanded water volume to go. The tank contains an air cushion separated from the water by an internal diaphragm or bladder, allowing it to absorb changes in pressure as the water heats and cools.
Expansion Tanks & Johnson City Plumbing Code
Johnson City follows plumbing-code requirements for thermal expansion control in applicable closed plumbing systems. When a storage water heater is supplied through a pressure reducing valve (PRV), check valve or backflow preventer, thermal expansion must be properly controlled. An appropriately sized thermal expansion tank is a common method used to provide that protection.
Proper installation involves more than simply attaching an expansion tank near the water heater. The tank must be appropriately sized for the system and properly installed and pressurized based on the home's water pressure and plumbing configuration.
Signs an Expansion Tank May Be Failing
Expansion tanks do not last forever. A failed or waterlogged expansion tank may no longer be able to absorb thermal expansion effectively.
Possible signs of an expansion tank or pressure-related problem can include:
- Water leaking from or around the expansion tank
- Visible corrosion or deterioration
- Unusual pressure fluctuations
- Water heater relief valve discharge
- Recurring plumbing leaks or fixture problems
- An expansion tank that has become waterlogged
Expansion Tanks, PRVs & Water Pressure Work Together
An expansion tank and a pressure reducing valve perform different jobs, but both can play an important role in managing pressure within a plumbing system. The PRV regulates incoming water pressure, while the expansion tank helps accommodate pressure changes created as water is heated.
If an expansion tank repeatedly fails or a plumbing system is experiencing pressure-related problems, checking the home's water pressure and PRV can help identify whether another condition is contributing to the problem.
Expansion Tank Replacement
If an existing expansion tank is leaking, damaged, waterlogged or no longer functioning properly, replacement may be necessary. Marc Francis Plumbing can evaluate the existing tank, water pressure and water heater configuration and install an appropriately sized replacement when needed.
We can also evaluate whether an expansion tank should be installed when replacing or modifying a water heater system.
Commercial Expansion Tank Service
Thermal expansion also occurs in commercial plumbing and water-heating systems. Commercial applications may require different tank sizes and system configurations based on water volume, operating pressure and equipment requirements. Marc Francis Plumbing provides expansion tank evaluation and replacement for appropriate commercial plumbing applications.
Expansion Tank Service in Johnson City, TN
If you have a leaking expansion tank, pressure concerns or questions about whether your water-heater system has the proper thermal expansion protection, Marc Francis Plumbing can evaluate the system and recommend the appropriate solution.