I'm replacing my old hot water heater and I have noticed there is not a thermal expansion tank. The house is in Florida built around 2002. My question is, is this plumbing setup what they used to provide for expansion? The line goes back into the wall but I don't know if it terminates into a drain. I've looked at neighbor plumbing and their line goes into drip pan not into wall. I'm From Michigan and have never seen a setup quite like this.

Is the 3/4 to 1/2 line going into the wall for thermal expansion?

 

Your system is not setup to accommodate expansion. Your piping was just done that way because it was easy.

It appears the line from the wall with a shutoff valve is the cold water supply. It then splits and the left side goes back into the house for toilets, cold taps and it looks like a refrigerator ice maker. The branch to the right feeds cold water to the water heater. Then the line on the left with braided stainless flex hose is the hot water out that gets fed into the wall to go to your sinks & faucets. Any pipe going into a drip will likely come from the temperature and pressure (T&P) safety valve on the side of the tank.

 

The line that looks like it might go back into the house to supply water to a refrigerator or ice maker is the line I have a question about. I assumed it supplies a refrigerator as well but when I looked at my neighbors plumbing setup it was identical except for that line. His line instead of going into the house turned into a drip tube that went into the drain pan. I assume his line is ment for thermal expansion

 

The line that looks like it might go back into the house to supply water to a refrigerator or ice maker is the line I have a question about. I assumed it supplies a refrigerator as well but when I looked at my neighbors plumbing setup it was identical except for that line. His line instead of going into the house turned into a drip tube that went into the drain pan. I assume his line is ment for thermal expansion

 

A hose like that is not a expansion device. Your neighbor probably had a leak and just put the hose into the catch pan instead of removing and capping the connection.

 

I'm sorry, I think I've created some misunderstanding with the picture and my question. The line I have the question about is the line that 90 up from the pex goes into a check valve then reduces to 1/2 inch going into the wall in the upper portion of the picture not the braided water line. There is a refrigerator on the other side of the wall so my thought is that this line could supply the refrigerator. But why would they use a check valve? I'm really trying to avoid cutting into the wall to find out if they used this line as a makeshift heat expansion. Sorry again for the confusion, and thanks for the help

 

I don't know why everything has to be for expansion. If you don't have an expansion tank at the water heater you do not have anything for expansion.

Some water circuits like for irrigation, automatic pool/pond fillers, swamp coolers are required to have back flow preventers (check valves).

 

""I don't know why everything has to be for expansion.""

Long long time ago (and also not so long ago) nobody worried about the expansion of every new tankful of water as it is heated.


Much of the time the expansion pushed back into the water main. Other times the pressure was relieved by a leaky faucet somewhere in the house. On a well system the pressure tank doubles as an expansion tank provided there is no closed valve or check valve on the way to the water heater. If water is used in dribs and drabs after a lot of hot water was used, for example in families where people take their bath before brushing their teeth, some of the pressure was relieved. If worse came to worst the temperature & Pressure relif valve tripped and someone whispered under his breath that the water heater became overheated but they did not want to turn the temperature dial down because then the family"ran out of hot water."


It is highly unorthodox to install a length of extra fat pipe to combat expansion let alone bury it in the wall. Anyway the fat pipe wouldn't accomplish anything useful here.


In many cities today the plumbing code requires an expansion tank for the water heater. It is easy to install one on practically any plumbing system that does not have one.

 

And, long ago there were not back flow preventers in water meters or people didn't even have meters. Without a check valve as the water was heated and the pressure rose it could push the expanding water back out into the water main. This is unsanitary since you could push contaminants from your piping out to other people. So, water meters now have a check valve and there isn't anywhere for the pressure to go especially with more rigid water pipes like steel and copper. Even without a expansion tank the pressure rise isn't harmful to most systems but in some cases it can damage pipes or cause the temperature & pressure (T&P) safety valve on your water heater to open and relieve the pressure. If you are concerned about it, install an expansion tank on the cold water line feeding your water heater.