Ask Experts Questions for FREE Help !
Ask
    hanitagila's Avatar
    hanitagila Posts: 1, Reputation: 1
    New Member
    		  
    #1

    Jul 7, 2010, 12:08 PM
    Does a PRV take the place of an expansion tank? If I have one, do I need the other?
    Have a PRV and wanted to know if I also should have an expansion tank. A plumber that was going to replace my hot water heater wants to sell me an expansion tank also for 175-225.00. Is this necessary? Thank you, Julie
    ma0641's Avatar
    ma0641 Posts: 15,675, Reputation: 1012
    Uber Member
    		  
    #2

    Jul 7, 2010, 02:19 PM
    Every hot water heater has a PRV that SHOULD open with over pressure or excessive temperature. However, they are known to clog with hard water and also open and flood basements-that's why they are vented outside or into a floor drain--but I have seen them jury rigged to vent inside. If your local water supplier has installed a backflow preventer on the water supply line or plans to do so, you need an expansion tank which has a bladder inside and equalizes the house pressure. If you are on a well you don't need one. The backflow preventer is a safety device to prevent possibly contaminated water from your house entering a public system if the line pressure should drop below your house pressure. The price you quote is not out of line with buying the tank, fittings and installation.
    afaroo's Avatar
    afaroo Posts: 4,006, Reputation: 251
    Ultra Member
    		  
    #3

    Jul 7, 2010, 03:05 PM

    Hello Ma0641,

    FYI, The pressure regulator valve (PRV) are installed to control the water pressure to your house, the temperature and Pressure valve (T&P) are installed at the water heater as a safety device to prevent the water heaters from explosion in case the pressure or the temperature exceeds inside the water heater, Thanks

    John
    KISS's Avatar
    KISS Posts: 12,510, Reputation: 839
    Uber Member
    		  
    #4

    Jul 7, 2010, 03:47 PM

    Some PRV's don't require an expansion tank. Backflow preventer's do. The expansion tank with a PRV makes sense.
    Here is an idea about parts cost: PlumbingSupply.com - Water heater thermal expansion tanks
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Expansion tank [ 1 Answers ]

I notice on another response that the expansion tank should not be located at the inlet to the hot water tank. That is exactly where the plumbers put mine. What is the problem with that location and where should it be located?

Does thermal expansion tank require PRV? [ 10 Answers ]

Thermal expansion tank required by City... no backflow preventer, pressure gauge or PRV? Latter aren't required if the psi doesn't doesn't exceed 80? How do you check water pressure without having to install the pressure gauge? Will the Thermal Expansion Tank work w/out anything stopping...

Do I need an expansion tank [ 1 Answers ]

The temperature and pressure relief valve on my gas hot water heater has been leaking for a while, we have a small bucket catching the water and dump it every few days. I decided to do something about it this weekend and replaced the T&P valve. New T&P leaks so I was thinking I may have a pressure...

Expansion tank [ 2 Answers ]

Recently my submerged well pump has been running every 4 minutes and then shutting down, I also noticed that water pressure is lower than usual and that the pump runs to keep the pressure at 28-30 psi. Is there a problem with the expansion tank?

Use of expansion tank [ 1 Answers ]

Why do I use expansion tank in a chilled water system?

View more questions Search