Is an expansion tank the same as a pressure tank?

The biggest difference between pressure tanks and expansion tanks is in where they’re used. Expansion tanks are installed above a water heater and help to protect it when hot water expands. Pressure tanks are installed near your well pump and help to protect and extend its lifespan.

Do you need an expansion tank if you have a pressure tank?





An expansion tank is always highly recommended if you have a ‘closed-loop system’ caused by any kind of check valve or pressure regulating valve installed on your house’s water supply line. A common illustration compares having high water pressure in your home to having high blood pressure.

What’s the difference between a pressure tank and a bladder tank?

Bladder type: The operating principle is the same as that of a diaphragm tank. The pressure difference caused by the squeezing of the air can reach the storage and discharge of water. The biggest difference between the diaphragm tank and the bladder tank is the rubber diaphragm and the water outlet in the tank.

Is an expansion tank a pressure vessel?

It is a pressure vessel and it was inspected and certified. It also carries a third party guarantee written in a U-1 form. A standard non-code tank is made of different lighter materials and does not have a third party inspection.

What happens if expansion tank pressure is too high?

If the pressure is too high, it can wreck even a new expansion tank. Too low of psi, and the bladder will never “squish” to take up expansion. The psi on the in line psi after the PRV, and the precharge on the expansion tank should be the same.

What PSI should my expansion tank be?





Expansion tanks are pre-charged with a 40 PSI air charge. If the inlet water pressure is higher than 40 PSI,the expansion tank’s air pressure must be adjusted to match that pressure but must not be higher than 80 PSI.

Is a pressure vessel the same as an expansion vessel?

Also known as such as expansion vessels, pressure accumulators and surge arrestors. A pressure vessel prolongs the life of your pump by providing a reserve of pressurised water to your system. It therefore limits the number of starts of and wear on the pump when it is used for quick short periods of time.

What happens if you don’t have an expansion tank?

As plumbers know, the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into. Without an expansion tank, pressure would be distributed to the entire plumbing system, straining it and decreasing its lifespan.

Do all water heaters need expansion tank?

Short answer? If your home has a “closed” plumbing system, then yes, you’ll need an expansion tank. You see, homes have either an open or a closed plumbing system.

What is purpose of expansion tank?



The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excessive water pressure. If water pressure gets to high it can damage valves in plumbing fixtures, joints in supply pipes and the water heater itself.

Should an expansion tank be full of water?

Checking Your Water Pressure
You can also check your expansion tank’s pre-charge pressure by knocking on the side of the tank with your knuckles to determine if it’s full of air or water. Pre-charge pressure that’s too low may be indicated when the tank is full of water.

Where should an expansion tank be located?

The expansion tank (potable water type) should be installed on the inlet cold-water line. It can be installed anywhere in the building on the cold-water supply (after the regulator). It is usually installed by plumbers on the cold-water inlet of the water heater.

Will an expansion tank lower water pressure?



A water heater expansion tank is simply a small tank that absorbs water into a bladder to reduce excess pressure in your water heater.

How do I know if my expansion tank is working?

Finally, testing your Thermal Expansion Tank is important and should be tested once a year when you flush your water heater. If your Thermal Expansion Tank is hanging from a pipe, you would push the Schrader Valve (air valve), located on the bottom of the tank, if the air is released then the tank is working properly.

How often should I drain my expansion tank?

Draining the expansion tank should be done periodically, usually once or twice a year. We recommend doing this maintenance before the cool season so you don’t have to work with hot water and risk getting burned. Turn off the boiler and close the water supply valve. Allow the tank to cool if necessary.

Do I need to bleed my expansion tank?

You shouldn’t be needing to bleed air when you drain the expansion tank. If you have an air problem in your system it’s a separate issue. The water pressure tank (it’s not an expansion tank) smooths the pressure or delivery of water into the building and prevents short-cycling or rapid on-off pump operation.

How do you maintain an expansion tank?



Is There Maintenance on Expansion Tanks? A hydronic system should be completely closed. There should be no leaks and the cold fill pressure should remain constant at room temperature. The PRV should not need to be adjusted.

How long do expansion tanks last?

Like most appliances in your home – expansion tanks do have a lifespan so at some point – they will need to be replaced. The average lifespan of an expansion tank is between 5 to 10 years.

Do expansion tanks stop water hammer?

An expansion tank is a small football-shaped tank that is half-full of air. This takes care of absorbing the shock when the fast flowing water is suddenly shut off to stop water hammer. It is often located somewhere in the utility room or basement near the water heater.

How much does it cost to replace an expansion tank?

$145 – $350, Installed
The cost to install a water heater expansion tank ranges from $55 and up for the rare DIY project, to about $350 when a pro adds an expansion tank to a large residential water heater.