QA

How To Replace An Expansion Tank

Can I install an expansion tank myself?

This is a moderately difficult DIY project that shouldn’t be tackled unless you have some experience with plumbing work. Novice DIYers may want to have this work done by a professional plumber, but more experienced DIYers can usually do the work in an afternoon.

How much does it cost to replace an expansion tank?

The job of the thermal expansion tank is to absorb the extra water volume so that the excess pressure does not cause undue wear and tear on the water heater and other fixtures in the home. The cost to install a new Thermal expansion tank can range from $279 to $443.

How often should expansion tank be replaced?

Between five and 10 years is the average lifespan of your tank. If your home’s water pressure matches the air pressure in your expansion tank, you can extend the life of your tank.

What happens if expansion tank is full?

Pre-charge pressure that’s too low may be indicated when the tank is full of water. Low pressure can cause too much water from entering the tank. It could also indicate that the diaphragm is no longer functional, which means that there is nothing to prevent the water from entering.

Can PEX be used for expansion tank?

Connect Tank to Tee Cut a piece of PEX to run between the expansion tank and the tee-fitting that you inserted in the hot water tank cold water supply line. If you have other fittings between the two, you will need to cut pieces of PEX to connect those as well.

Is it code to have an expansion tank on water heater?

The California Plumbing Code (Section 608.3) and the California Mechanical Code (Section 1005.0) requires a thermal expansion tank, or listed equivalent, to be installed to water heating systems to relieve excessive building pressure during the heating process.

Is an expansion tank necessary?

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. However, the long-term wear and tear of this excess pressure can reduce the life expectancy of everything in your plumbing system.

How do you know if your expansion tank is bad?

If it makes a dull thud rather than a hollow sound, your tank is full of water and needs repair or replacement. You can also gauge this by feeling the tank, which will be cool where it’s holding air and warm where it’s holding water. If more than half the tank is warm, you have a problem.

Why would an expansion tank leak?

And sometimes, as water expands after being heated, it outgrows the space within the tank. When this happens, excess water is immediately sent to the expansion tank to lower pressure levels inside the water heater. But sometimes, due to wear and tear, your expansion tank may start leaking.

How much is a water expansion tank?

Water heater expansion tank prices start at around $40 and range up to nearly $200; pricing is largely dependent on the size of the tank. For most residential installations with 40- or 50-gallon water heaters, a simple 2-gallon tank is fine.

What happens when an expansion tank fails?

Oftenthe diaphragm dividing the two systems will fail, causing the two systems to become one. When this happens, the expansion tank turns into a “dead leg” that will eventually cause damage and premature failure to your water heater.

Can a bad expansion tank cause high water pressure?

The most common source of high water pressure is actually the municipal water supplier. It’s also possible that you have a faulty expansion tank on your water heater. At the end of the day, the cause of high water pressure is usually something outside of your control.

Why does my expansion tank keep failing?

The most common expansion tank problem in a diaphragm tank is losing small amounts of air through the valve. When this occurs, more air needs to be added to the tank. If the tank does not hold its air pressure after you complete this fix or it fills with excess water, you may need to replace the diaphragm.

What is the difference between an expansion tank and a pressure tank?

The most significant difference between expansion and pressure tanks is their functionality. An expansion tank handles water expansion and provides protection for water valves and heaters. On the other side, the pressure tank lengthens the lifespan of the pump.

Do expansion tanks need to be drained?

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.

Can an expansion tank explode?

In fact, the tank may explode! Thermal Expansion Can Cause Hot Water Heaters to Explode! A typical hot water heater in an “open” sys- tem has only a temperature and pressure (T&P) valve to prevent a rupture of the hot water heater (figure A). Open systems allow expanding hot water to push into the cold water line.

How do you bleed an expansion tank?

Turn the boiler off, and wait a couple of hours to let the water cool down. Find the shutoff valve and the drain valve on the expansion tank. (The shutoff valve goes into the furnace; the drain valve is on the bottom of the tank.) Close the shutoff valve.