# Water heater expansion tank question please



## Gregplumb (Oct 13, 2015)

Could someone tell me how you know exactly when an expansion tank is needed on a water heater. I understand it is when the water system is a closed system, but a little fuzzy on how you identify a closed system. 

If the main water line entering a house has a pressure regulator does that mean that 100% of the time you need an expansion tank on a heater?

Could someone please tell me what you look for in houses that tells you for sure that it is a closed system?

Thanks for any replies
Greg


----------



## plumbdrum (Nov 30, 2013)

Nobody here is going to tell you, but if you hire a plumber instead of being a cheap home flipper ,they may help you.


----------



## Gregplumb (Oct 13, 2015)

plumbdrum said:


> Nobody here is going to tell you, but if you hire a plumber instead of being a cheap home flipper ,they may help you.


 thanks for being such a giant prick.....have a blessed day!


----------



## plumbdrum (Nov 30, 2013)

Your very welcome, now show yourself to the door to the DIY website.


----------



## plumberkc (Jun 23, 2011)

It has to do with the type of piping and if you have a PRV. As long as you have a PRV you can avoid having to install a thermal expansion tank by using CPVC water supply lines.


----------

