Hello everyone,
I am in a Michigan and don’t normally see expansion tanks above water heaters.
Any help understand this would be much appreciated!
A water heater expansion tank is another small tank that is attached to the water supply pipe of the water heater.
It separated the text with the pictures in between. I tried to mention that it didn’t appear to be for the water heater. I want to know why it installed at the water main and exterior faucet.
Thanks
I’m not asking about the water heater I wanted to know why it is attached to the water main and exterior faucet.
It can be installed anywhere on the closed water system to accomplish the objective. I see them laying in an attic sometimes with a tankless installed outside.
The only thing that makes sense to me is that it was put there to equalize small pressure fluctuations in the water supply. Perhaps there is something (building, activity) in the neighborhood that causes water pressure fluctuations?
Thank you! This was the answer I was looking for. I did see that in the article but was on the job so it took me awhile before I had the chance to read it.
I was thinking the same thing. But, it appears that the apparent backflow flow preventer makes the house system closed.
If it did not have the backflow preventer, it would be an open system and subject to the changes of exterior pressure fluxuations.
I’ve seen them located in areas away from the WH a few times. Not a probem as long as it’s installed between the anti-back flow device/check valve and the WH inlet.
Just behind the expansion tank there is a foundation crack exhibiting moisture intrusion, efflorescence and water stains.
As well, $43.5 Million NIBCO PEX Class Action Settlement Announced.
Here is a quick way to see of the pex in the home qualifies. Also, remember this tubing was no longer manufactured after 2013, some fittings as late as 2015.
There are several ways to find out if your home has these Covered Products.
First, you can try to identify it yourself:
- The Tubing has a print stream with NIBCO’s brand and the “1006” designation stamped on it, among other identifying pieces of information. If you have flexible plastic tubing that is not stamped “1006,” then that tubing is not part of this settlement. Click here for a photo.
- The yellow brass Fittings are stamped “NIBCO F 1807” and can be located at joints in PEX tubing. Click here for a photo. If your PEX system includes yellow metal fittings and they are also stamped with interlocking ovals (click here for photo) or stamped DR (click here for photo), then they are not part of the settlement. Poly fittings are not part of this settlement.
- The Fittings can be secured to the pipe by stainless steel Clamps. These clamps will be marked NIBCO. Click here for a photo.
https://www.pexsystemsettlement.com/frequently-asked-questions.php#faq12
This is all great info! I didn’t know pex had a lawsuit.
Credit to Robert for identifying the material in your photo. Of course, you need more identifying features. And even then, it is outside of scope of course.
There have been multiple, and most are long expired. So, never assume, and if you mention to a client, ALWAYS be non-committal as to the current status. Class Actions change all the time. Pass along the basic info and let them (clients/realtors/attorneys) do the homework for the details.
Hey Larry, that makes me think; the backflow preventer keeps house water from flowing back into the main supply, but doesn’t prevent the main supply from entering the house. If there’s a spike in the supply pressure the backflow will allow the water to come in, but will prevent it from flowing back out when the spike subsides. This would result in an increase in pressure on the inside closed system, wouldn’t it? The tank would help relieve some of the pressure at this point, I would think. I may be way off base on this as I’m still in the middle of my first cup of coffee this morning.
I see them all the time and also (yesterday) PRVs (Pressure Relief Valves).
First, the water heater manufacturer’s installation instructions require thermal expansion protection on plumbing systems that are closed. In the old days, water heaters pushed the expanding hot water into the vastness of the city system. But in recent years, many (maybe most) municipalities have been putting check valves/backflow preventers at residences to prevent the possibility of contamination from backing back into the city system. So, the water heater can spike the water pressure in a house. Thermal expansion tanks absorb that pressure increase.
They are notorious for failing. It’s controversial to check them. At the Pro Inspector Conference a few weeks ago in NJ, a speaker recommended to never check them to see if they are pressurized or waterlogged. I disagree with him, but we all decide on how we are going to do our inspections.
Secondly, expansion tanks can relieve water hammer, but I’ve never encountered water hammer on a PEX system.
Hi Anthony, not speaking for Larry, but areas that have, or are subject to, higher than required water pressure from a public water systems should have a pressure regulator, which I normally see installed downstream of the check valve. The purpose of an expansion tank is alleviate thermal expansion in the system.
Hope this helps. 
Hi Anthony, just read you post and I agree with Kevin’s comment below:
