The California Plumbing Code (Section 608.3) and the California Mechanical Code

Is water heater expansion tank required?

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.

Is an expansion tank required by code in Georgia?

Yes, section 607.3 Thermal expansion control – A means of controlling increased pressure caused by thermal expansion shall be provided where required in accordance with Sections 607.3. 1 and 607.3. 2.

Is an expansion tank required by code in NC?

Answer 1: Per section 607.3 of the 2012 NC Plumbing Code a device for controlling thermal expansion is required between the water heater and any device that can stop water from flowing back to the cold water source.

Why are expansion tanks required?

The expansion tank serves as a backup system to prevent overworking your plumbing. The excess water volume, instead of causing too much pressure on the plumbing, rushes into the expansion tank and lowers the pressure in the water heater to safer levels. This ultimately protects it from damage.

Does a 20 gallon water heater need an expansion tank?

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. A closed plumbing system prevents water from flowing in the reverse direction (i.e., water won’t flow back into city lines once it enters your home’s pipes).

What is the purpose of an expansion tank in plumbing?

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 my expansion tank be empty?

You are correct. The expansion tank is usually about half full of water and half full of air–by volume. One tank full of air at atmospheric pressure will be about half its volume when pressurized. When in doubt, drain it.

Do I need an expansion tank with PEX?

An expansion tank is only required when the water supply system has a backflow prevention device or check valve. The extra pressure caused by thermal expansion was apparently an issue in the home. I would strongly suggest that you include it in your new set up. Don’t rely on the pex to expand and relieve the pressure.

Can an expansion tank explode?

As water heats up, it can expand dramatically, and if it’s hot enough to turn into steam, this can add even more pressure to the water heater. If the relief valve is malfunctioning, this can lead to an explosion.

Article first time published on

Can an expansion tank be installed anywhere?

Your expansion tank can be anywhere on your plumbing system and does not need to be installed in close proximity to the water heater. It is most commonly installed using a “T” at the cold inlet to the water heater. But, functionally, it can be installed anywhere on the cold inlet line.

What happens if I overfill my expansion tank?

Coolant expands as it heats and contracts when it cools. The extra space prevents damage to your engine and hoses. … In worst case scenarios, overfilling your antifreeze tank can lead to electrical damage if overflow comes into contact with engine wiring.

Does it matter which way an expansion tank is installed?

Expansion tanks can be installed in any direction. Whether oriented uprightly, horizontally, or even upside down, the expansion tank will function properly without any adverse effects. When putting an expansion in an abnormal position (specifically sideways or horizontally), make sure to support the tank.

How do you know if your expansion tank is full?

Once you completely open the valve, you can measure and note the 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.

Is it bad to overfill DEF fluid?

The main reason not to overfill is because def fluid will freeze as it is mostly water. If the tank is overfull and freezes it could crack and leak.

Can you put to much antifreeze in your car?

This is where the real dangers of overfilling your coolant lie. Hot coolant leaking throughout your engine bay can cause serious damage to wiring and electrical components. If you do end up with a burst hose, your engine could be starved of coolant and cause some pretty big problems.

What bar should my expansion tank be?

It rarely needs to be anything more than 1.5 bar in most domestic properties. Anything more and the water may not expand into the air at the required time and could risk the high pressure relief valve opening or worse.

Does an expansion tank need to be pressurized?

The recommended water pressure is between 50 and 60 PSI. Thermal Expansion Tanks contain an air bladder which is pressurized with air, and expands and contracts to absorb the expanded water from the water heater. needed. Check the air pressure in the Expansion Tank using a tire gauge.

Should an expansion tank be vertical or horizontal?

In general, the tank can be installed vertically above or below the plumbing, or horizontally. Typically, the tank is only required to be supported when installed in the horizontal position. Most smaller tanks are designed to be supported by the plumbing, when installed in the vertical orientation.

How much does it cost to install a water heater 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.

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.