How To Know If Your Portable Water Expansion Tank Is Damaged

Look for signs of condensation or air blockage; that’s how to know if your portable water expansion tank is damaged. Leaving your damaged tank unattended can be dangerous, so be alert for the signs and have it repaired once you spot it.


how to know if your portable water expansion tank is damaged

What Is A Water Expansion Tank?

These tanks protect your water heater from thermal expansion. This tank is helpful in colder months when you use the heater more often.

Water expands as it heats up, increasing the pressure inside your water tank. If you leave high pressure in the tank, it may explode or damage the pipes in your building.

That’s why expansion tanks are helpful; they provide an outlet for the built-up pressure, so it doesn’t just stay in your tank. 

Here is an article to learn more about what is an expansion tank for a water heater.


5 Common Signs And Problems

Portable water expansion tanks are pretty sturdy, but they may become damaged after a long time. 

You may not notice any tank issues, especially when your water is functioning well. However, it’s essential to check once in a while for problems like these.


1. Air blockage

Water systems need air to function correctly, but sometimes this air can get stuck and lead to a hydronic airlock.

Hydronic airlocks happen when water can’t flow through the heater or pipes. If you notice your radiators have less water than usual, it may be a sign of this airlock.

Avoiding airlocks is one of the primary functions of expansion tanks, so if this happens, it means the tank isn’t functioning well. 


2. Venting water

Expansion tanks can suffer wear and tear over time, so you may notice some leaks. You must observe your tank and find out where the leakage source is for repair. 

You may try some D.I.Y. repair on the pìpies, but it’s always best to contact a plumber when these problems start.


3. Condensation

Once you find condensation buildup on your expansion tank, it’s damaged. You must call a plumber to fix all the issues.

If you leave the condensation unattended, your tank will rust and develop more severe damage. The droplets may also cause problems with any flooring or electricals underneath.


4. The steel tank needs recharging

Older expansion tanks use steel to maintain air and water pressure. Over time, the water may hold that air and cause the tank to lose pressure.

You may try “recharging” your steel tank by closing the isolation valve and draining out the water, but it’s better to have a professional do it.


5. Not enough air in the diaphragm tank

Modern expansion tanks use rubber to maintain the internal pressure. However, the pressure gets affected if the tank loses air through the isolation valve.

You must add more air to the tank when this happens. Use an air compressor pump and fill the tank up until 12 P.S.I.


Safety Risks Of A Damaged Water Expansion Tank

People usually take the expansion tank for granted, especially when there aren’t any hot water issues. Most tank problems are not noticeable in the early stages, and you only feel the effects when it’s a severe problem.

If you leave your expansion tank issues unattended, it may explode. This could be risky for people near the vicinity when it happens.

The explosion may also cause severe water damage to the flooring and electricals. That’s why it’s essential to monitor your expansion tank and call a professional to fix any problems. 


Tank Repair Costs

Most people may choose to fix the expansion tank themselves. It’s possible, and you may read this guide on how to replace expansion tank on water heater

However, hiring a plumber to help with your repairs is safer as they have more expertise in handling the pump.

The tank cost, support type, and accessibility can factor in the total cost of your repair. The total cost may be $700, depending on the severity of the damage.


How To Avoid Water Tank Problems

Expansion water tank repair can be pricey; it’s always better to monitor the tank before anything severe happens. Here are other ways to avoid expansion tank issues.


1. Feel the tank

The top must be cool, and the bottom must be warm. If both parts feel the same, then your tank has some damage.


2. Do a tap test

Listen to the sound the tank makes when you tap on it. If it sounds hollow, there’s air inside, and it’s working perfectly. 

If it sounds dull, then you may need to replace the tank.


3. Monitor the pressure release valve

Look out for dripping on the valve. If you notice any moisture, then your tank needs repair. 


4. Upgrade the tank before it fails

Try to change the tank every time you do the heater. This practice will save you from higher expenses in the future. 



An expansion tank is helpful for your water heater since it helps with the water pressure. However, this tank can suffer some damage with constant use.

Checking for signs like condensation or airlocks is the best way how to know if your portable water expansion tank is damaged. Fix the problem once you see these signs to avoid damage and higher repair costs.

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