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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.
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.
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.
Will an expansion tank increase water pressure?
The expansion tank contains air, which is highly compressible. Expanding water from the water heater can flow into the expansion tank, where the air compresses, making room for the increased volume of water. Water pressure in the system doesn’t increase significantly.
What happens if expansion tank pressure is too low?
If the precharge pressure is too low the tank may be excessivly full of water even before the thermal expansion takes place which may limit room for expansion, add additional weight to the tank, and, or, stress the tank bladder. These factors may reduce its service life.
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.
Is an expansion tank required for a water heater?
While expansion tanks are required by code in most closed-loop water heater systems, they have a reputation for failing. Common expansion tank issues include: Rubber Diaphragm Wear Out.
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 I know if my expansion tank is working?
The tank should be full of air and therefore sound hollow. 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.
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.
Will an expansion tank fix water hammer?
Although an expansion tank may help solve a thermal expansion problem, water hammer may be so powerful that an expansion tank won’t take care of the problem. A water hammer arrester may be installed to reduce the effects of the water hammer. In some cases some re-engineering of the system may be necessary.
Why is the expansion tank on the cold side?
One expansion tank manufacturer states: “We recommend the cold water side installation because the tank is not insulated. When the expanded volume enters the tank, it will cool down. With the tank on the cold water side, this expanded volume will pass through the water heater before going out to the faucets.”Feb 28, 2010.
What size expansion tank do I need for a 40 gallon water heater?
General Guidelines for Sizing an Expansion Tank Water Heater Capacity Supply Pressure (psi) Expansion Tank Size 40 to 60-gallon 40-50 psi 2-gallon 40 to 60-gallon 60-80 psi 3.2-gallon 80-gallon 40 psi 2-gallon 80-gallon 50-60 psi 3.2-gallon.
Why does expansion tank fill with water?
Some tanks fail when a leak develops in the diaphragm. This usually causes the tank to fill with fluid and become “water logged.” You can check for this by pressing in the stem of the Schrader valve. If a stream of liquid comes out the tank is toast.
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.
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.
Why is the water in my expansion tank hot?
Faulty coil in the hot water cylinder Over time, this coil can become perforated, meaning there’s hole in the coil which allows water for the central heating into the domestic hot water being stored in the cylinder. This rise in water levels can then lead to the feed and expansion tank overflowing.
