Ask Experts Questions for FREE Help !
Ask
    ditchdigger's Avatar
    ditchdigger Posts: 2, Reputation: 1
    New Member
     
    #1

    Mar 16, 2008, 06:58 PM
    Installing water heater expansion tank
    I'm on a water well system & a check value is installed between the well pressure tank and the Hot water heater.

    I think the check value is limiting the expansion of hot water & causing the T&P value on the hot water heater to open periododicly.

    Will installing a small hot water expansion tank most likely fix the T& P value from releasing water?

    What should I set the precharge pressure on the small expansion tank ? My well pump is set cycle on at 30psi and shut off at 50psi.
    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
    Senior Plumbing Expert
     
    #2

    Mar 17, 2008, 03:34 AM
    Hello DD:

    Yes... installing an expansion tank should help to eliminate the issue. Install the expansion tank in the cold water supply to the water heater (after shutoff, but before vacuum breaker if present) on the horizontal if possible (less stress on nipple of expansion tank), and a hanger is always a good idea.. ;) . You will need to know the SIZE of your water heater to purchase properly sized expansion tank.

    So need:

    1 - 1/2" copper x 1/2" female threaded tee (if 1/2" pipe)
    1 - roll teflon tape
    solder, flux, sandcloth, and torch
    1 - expansion tank.
    1 or 2 hangers (could be strap hangers or 3/8" threaded rod, 3/8" plate and split hanger)

    Most tanks come precharged, but read the instructions that come with the tank and set the pressure as suggested.

    Let us know if need more... and result. Good luck!. Mark


    If this helped, please RATE THIS ANSWER. Thank you.
    ditchdigger's Avatar
    ditchdigger Posts: 2, Reputation: 1
    New Member
     
    #3

    Mar 17, 2008, 05:23 AM
    I got a small 35 gallon water heater so I got a small 2 gallon hot water expansion tank(Watts DET-5)..

    The directions say to open faucet to allow the system pressure to equalize. Then set the pre-charge on the hot water expansion tank to that pressure.

    But I'm on a well and system pressure keeps dropping until it reaches around 30 psi , and then the well pump comes on and recharges the well expansion tank/system back up to around 50 psi.

    So what do I set the Pre-charge too?

    I read somewhere that >>>>
    Expansion tanks are pre-charged with a 40 PSI air charge. If the inlet
    Water pressure is higher than 40 PSI, the expansion tank's air pressure
    Must be adjusted to match that pressure but must not be higher than
    80 PSI.<<<<<<<

    So do I set the Pre-charge on the hot water expansion tank too 50 psi then?
    ... or should I just leave it at the 40 psi it comes from the factory with?
    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
    Senior Plumbing Expert
     
    #4

    Mar 17, 2008, 05:54 AM
    Hey DD... According to Emerson Swan (manufacturer of these tanks)... 49 PSI is correct setting... try it out. Let us know how it goes... Mark

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!

Connecting an expansion tank to a water heater [ 4 Answers ]

I recently replaced my water heater. It now seeps occasionally from the pressure relief valve. I plan to add an expansion tank. Can I connect the expansion tank to the water heater by using a drain valve at the bottom of the water heater? Usually it is connected to the cold water inlet, but since...

Water heater expansion tank [ 2 Answers ]

I have a four year old water heater that is leaking out the pressure release down tube and there is an expansion tank fixed to the cold side. I tested the pressure on the expansion tank and it reads 0.00. Is there supposed to be some amount of pressure reading in the expansion tank or can I add...

Water Heater Expansion Tank [ 1 Answers ]

It's me again. I meant an under the air conditioner hot water heater. The current one is 31" high. It has an expansion tank, but I was told it wasn't necessary. I'm in a second floor condo. Is it really necessary and if so, why? Thanks a lot.

Water heater expansion tank [ 2 Answers ]

I need a new water heater and one plumber says the expansion tank on the side is not necessary. Is it? What is the average cost of a 40 gal, under air water heater already hard wired? 2nd floor. Thanks

Water heater expansion tank [ 4 Answers ]

Read a post here concerning the water line back flow preventer/expansion tank and am familiar with its operation and purpose when using city water. My question is, is this setup recommended or even needed on a well water system? My feeling is that the holding tank would take up any expansion. ...


View more questions Search