1. Hot Water Expansion Tank Installation
2. Hot Water Expansion Tank Problems
3. Hot Water Boiler Expansion Tank

Here is a video of my house showing the problem of water heater expansion, and the solution using an expansion tank. A hot water expansion tank is a very important part of a water heater. When water is heated it expands and needs a place where it can safely overflow to.

Expansion Tanks for Water Heaters An expansion tank prevents pressure increases due to thermal expansion of your water. As your water is heated from 50째 F to 120째 F, it expands by approximately 2%.

If you have a “closed system”, which means there is a backflow preventer or other device that prevents your water from flowing back into the water main, thermal expansion will cause very rapid pressure increases in your plumbing system. Food products manufacturing using microsoft dynamics ax 2012. Common questions about water heater expansion tanks include: What is a check valve?

The check valve is the mechanism that prevents backflow of thermally expanded water in the wrong direction. Without an expansion tank, increased pressure can cause unnecessary stress on your plumbing fixtures, including the water heater, and cut down on their working life. Does the expansion tank have to be installed on the cold side? Although expansion tanks can be installed on the hot side, we strongly recommend they be installed on the cold line, downstream of the shutoff valve. Where should an expansion tank be installed in relation to the hot water heater? 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. Can the expansion tank be installed at any angle? The expansion tank can be installed in any angle. This will conflict with info that comes with any expansion tank you buy at a retail store. The installation instructions that come with retail expansion tanks say the tank must be installed in a hanging vertical position.

Hot Water Expansion Tank Installation

Retail expansion tanks come with a “Saddle Fitting”, which allows the installation into the system without any soldering, thereby making installation easier for the average homeowner. The saddle fitting is a device that clamps around the pipe and has female threads that will accept the expansion tank. A small hole is first drilled in the pipe, then the clamp is placed so the hole lines up with the expansion tank inlet. We do not recommend using such a fitting. They are unreliable, and allow placement of the expansion tank in the above mentioned vertical hanging position only. We recommend using galvanized fittings or soldering the appropriate fittings into the system.

If you have more questions about water heater expansion tanks, please give us a call, or fill out the form below.

Old Amtrol tank next to the new Watts tank As mentioned earlier, all new expansion tanks come from the factory with some amount of pressure in the diaphragm, meaning the diaphragm will be inflated enough so that reaches the opening of the tank. On a functioning tank with pressure in the diaphragm, you should be able to stick your finger through the top and touch it.

However, when I inspected my old tank, I couldn’t feel the rubber diaphragm through the opening. That means it had indeed failed, as I suspected. I stuck my phone’s camera into the hole to get a peek at the failed diaphragm deep inside the tank.

Securing the new tank After making sure the tank was securely in place, I turned my gas valve back to ON, turned on my recirculating pump and opened the return line valve. Now, my system is once again protected against potential damage from thermal expansion and water hammer. I only spent $50 on the new tank, $9 on the water pressure gauge (which I’ll reuse often), and used a tire gauge I already had. The entire process, including the testing, took less than 30 minutes. I promise it’s something you can do, even if you’re not particularly handy. But this important piece of safety equipment in your house can’t work properly if it’s not set properly, and if it’s not tested regularly. I was surprised today when I discovered mine had failed, and glad that the fix was inexpensive and straightforward.

Hot Water Expansion Tank Problems

I’ve now added “Check expansion tank pressure” to my home maintenance schedule and plan to do it every six months (it’s easy to do when you’re flushing your tank and checking your anode), and suggest you do the same. As always, I welcome your comments and questions below!

Hot Water Boiler Expansion Tank

Special thanks to in Orem, UT for their expert advice on tackling this project, and for always providing the parts I need at a good price.