When water is heated, an expansion tank relieves excess pressure from the increased water volume. It’s, therefore, an essential appliance for those with gas or electric water heaters. However, a water heater expansion tank may fail over time due to air blockages or damaged diaphragms, necessitating their replacement to avoid costly repairs such as burst pipes.
How Long Does a Water Expansion Tank Last?
A water expansion tank can last anywhere between 5 to 10 years. However, the lifespan of your expansion tank depends on several factors, such as:
1. Maintenance
2. Water quality
3. Overall efficiency of your water system.
How to Maximise the Lifespan of Your Expansion Tank
Preventive measures are essential to prolong the life of your expansion tank. These include:
- Match your Pressures: Ensure your home’s water pressure matches the expansion tank’s air pressure. This balance helps prevent unnecessary wear and tear on the tank and keeps it functioning reliably.
- Install a Water Softener: Hard or mineral-rich water can cause sediment buildup and corrosion inside the tank, possibly leading to premature failure.
- Inspect the Expansion Tank regularly: Regular inspections can help you catch issues before they escalate. Look out for signs of failure, such as:
- Leakage around the tank or fittings
- Unusual sounds coming from the tank
- Fluctuations in water pressure
How to Know When a Water Expansion Tank Needs Replacing
Here are some tips and indicators to help you determine when to replace your water expansion tank.
1. Check your water pressure:Â You can measure your water pressure by using a water pressure gauge, which you can attach to the drain valve of your water heater. Turn the valve on entirely and note the pressure. This will help you determine if the system is experiencing extreme pressure changes caused by a faulty expansion tank.
2. Inspect for leakage:Â Look for signs of leakage around the valve connections or near the bottom of the tank. If you notice any damp spots or dripping water, it could indicate that the tank may need to be replaced.
3. Visible corrosion:Â Inspect the outside of the tank for any visible corrosion or rust, which may weaken the tank’s material and lead to failure over time.
4. Check the pre-charge pressure:Â A well-functioning tank should produce a solid sound, while a tank needing replacement may produce a hollow or dull sound.
5. Assess the tank’s age:Â If your tank has reached its expected lifespan, getting it checked and replaced if necessary is prudent.
How Much Does a Replacement Water Expansion Tank Cost?
The cost of a replacement water expansion tank can vary, typically from $60 to $200, depending on the tank’s size and type.Â
For instance, a 4-gallon expansion tank might cost between $60 and $90, while larger tanks over 5 gallons could range from $140 to $200.
Replacing a Water Expansion Tank Yourself
A licensed plumber can replace a water expansion tank. However, this is also a DIY job that you can do yourself.
- Turn off your water heater’s power and main water supply. This is an essential step to ensure safety while working on the system.
- Locate the expansion tank, which is usually situated right next to the water heater and connected to it.
- Drain the existing expansion tank. If necessary, attach a hose to the tank’s valve and drain the water to a suitable location. If your tank has an air valve, ensure it functions properly, as the trapped air ensures proper water flow through the pipes and heater.
- Disconnect the old tank by unscrewing any fittings or connections. If connections are particularly tight, you may need a pipe wrench and some plumber’s tape. Be sure to have a bucket or towel on hand to catch any water leaking during this process.
- Install the new expansion tank. Wrap the threaded connections of the new tank and your new water heater with the plumber’s tape to create a watertight seal. Carefully screw the new tank into place, making sure not to overtighten the connections.
- Slowly turn the cold water supply line and power back on. Check for leaks and ensure the new tank is functioning as expected. By correctly following the installation requirements, your hot water system should return to normal and be ready for use.
Frequently Asked Questions
What are the steps involved in replacing a hot water expansion tank?
- Turn off the power and water supply to your water heater.
- Drain some water from the heater to relieve excess water pressure.
- Use a pipe wrench to unscrew the old expansion tank from the pipe.
- Wrap Teflon tape around the threads of the new tank.
- Screw the new tank onto the pipe.
How do I determine the correct size of an expansion tank for my system?
To find the appropriate size expansion tank for your system, you need to know your water heater’s capacity in gallons and the incoming water pressure. The expansion tank comes with a chart or an online calculator you can use to determine the correct size based on this information.
Can an expansion tank be installed without professional assistance?
Yes, an expansion tank can be installed without professional help. However, it’s always best to consult a professional plumber if you’re uncomfortable with plumbing work or the process entails extra complications.
What indicators suggest that my expansion tank needs replacement?
Signs that your expansion tank needs replacement include:
- A sudden rise in water pressure.
- Water is leaking from the pressure relief valve.
- A drastic decrease in the system’s pressure.
- A notably shorter service life for your water heater.
What is the typical cost range for replacing a residential water expansion tank?
Replacing a residential water expansion tank can range from around $100 to $400, including parts and labor. Remember that costs may vary based on location, tank size, and the complexity of the installation process.
Are specific codes or regulations to be followed when installing a new expansion tank?
When installing a new expansion tank, local codes and regulations may need to be followed. It’s essential to check with your local building department or a plumbing professional to ensure compliance with these standards.
