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wpatters1229

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Dec 14, 2023
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Location
California
I want to install a new tank water heater. Mine is over 30 years old according to the manufacturer's date. I have never had an expansion tank. Just the safety valve that comes with the heater. How can I tell if my water service from the street has an anti-back flow device? This track of homes was built in 1947 so I am not sure if they cared about that then. Have never had any trouble with pressure in the lines etc. I think I will attach the new heater like it is. If not broken don't fix it!
 
Pictures of what? I just want to know if there is a way to tell if my water into the house has a back flow value so my water in the house can not flow back into the main water system. I have never had an expansion tank in over 60 years of having a water heater and wonder if I need one now. I am guessing that if there was a pressure build up the safety valve on the side of the tank must have opened just enough to release the pressure...I mean what else could there be unless the water system to my home does not have an anti-back flow valve.
 
An option would be to get a water pressure gauge ( 12 bucks ) that attaches to a hose outlet to see what pressures you are actually dealing with now. It measures the high readings. You just attach to a hose spigot ... turn the water on for 24 hours and see what the highest reading is ( Years ago we had to include an expansion tank in my Dad's system because the municipality had made changes after decades of no issues ) Your pipes are OK today but what will additional pressures do later.
gauge.jpg
 
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Another revelation ...... I thought all municipalities used check valves to protect their systems from contamination.
 
Yes,along time ago but there is no way to tell if a check valve has failed now there are testable backflow devices the test verifies if each check valve is working and if the relief valve works,usually the city tests them it's a specialized license
 
sarg said:
Another revelation ...... I thought all municipalities used check valves to protect their systems from contamination.
Click to expand...
A lot of municipalities do, they use a non-testable double check valve just after the meter on the customer side.
 
I have a water pressure guage since years ago my dishwasher was making sounds and I found the water pressure to the house was 110. I then install a reduction valve that feeds the whole house and set it for 70. We live near a water tank up on a hill so that explains it. So put the guage on the hot side of a sink and let it set for 24hrs with the spigot on. We have a laundry room sink right next to the water heater which should work fine.
Like I have written before we have had this setup for since 1947 and never had an expansion tank. The whole house is copper pipes 1/2 inch. Even the inlet to the cold water side and outlet to the hot side. No 3/4 anywhere. Seems to work fine.
 
You've answered your own questions and no one's opinion means more than yours if you're comfortable.
For me ..... if I had 70 psi in my system I would be more comfortable with the safety measure of an expansion tank.
 
If you have a PRV you need a thermal expansion tank.
 
I attached a pressure gauge to the hot water faucet that is right next to the water heater and turned it on. The pressure showed 60 and after about 6 hrs I looked at the gauge and the red indicator showed that at some time it was up to 120. Not near the safety valve rating of 150. Maybe after I replace the WH I will check it again and see if at that time I need to go to the trouble of getting a thermal expansion tank.
 
Well .... a 60 psi increase from the heater. Good luck with all your pipes , fittings & faucets from 1947 in the future.
 
As previously stated you need a thermal expansion tank. Why waste time and money not installing one with the new heater, or before if the heater will not be replaced in the next week.
 
sarg said:
Well .... a 60 psi increase from the heater. Good luck with all your pipes , fittings & faucets from 1947 in the future.
Click to expand...
Yes, that is much...but over that span of time I have replaced most fixtures, etc. All the pipes are copper and soldered. Never had any problems but I think I am going to install a tank and use those quick-connect fittings to make the job easier. They can be turned if the tank presents a problem with fitting properly. May just use a flexible pipe off a T to make it fit. Also, install a shut-off valve upstream from all that on the cold. The one that is there now is old.
 
Twowaxhack said:
He would install the cut off valve upstream from the expansion tank typically.
Click to expand...
I have lots of diagrams from google showing me. My question: Can I use a feed of flexible PEX to the expansion tank from a copper T so I can maneuver the tank to fit above my hot water tank? I was thinking of using quick connections on the copper to the copper T and then PEX to the tank. If the PEX and quick connections will with stand the pressure.
 
wpatters1229 said:
I have lots of diagrams from google showing me. My question: Can I use a feed of flexible PEX to the expansion tank from a copper T so I can maneuver the tank to fit above my hot water tank? I was thinking of using quick connections on the copper to the copper T and then PEX to the tank. If the PEX and quick connections will with stand the pressure.
Click to expand...
Yes, keep the pex 18” from the inlet of the water heater and away from the vent pipe if it’s gas.
 
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