Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (217)
    $38.45 each
    $147.80 box of 4
    $36.95 each
    582
    Mon, Apr 8
    582
    QtyArrives
    582 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (58)
    $31.95 each
    $122.60 box of 4
    $30.65 each
    463
    Mon, Apr 8
    463
    QtyArrives
    463 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (28)
    $65.85 each
    $253.00 box of 4
    $63.25 each
    111
    Mon, Apr 8
    111
    QtyArrives
    111 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $19.95 each
    $191.50 box of 10
    $19.15 each
    107
    Mon, Apr 8
    607
    QtyArrives
    107 Mon, Apr 8
    500 Mon, Apr 8 – Tue, Apr 9
    Questions? Call 1-888-757-4774
  • 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (40)
    $40.95 each
    49
    Mon, Apr 8
    49
    QtyArrives
    49 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $14.85 each
    $142.50 box of 10
    $14.25 each
    41
    Mon, Apr 8
    41
    QtyArrives
    41 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $17.25 each
    $165.50 box of 10
    $16.55 each
    83
    Mon, Apr 8
    83
    QtyArrives
    83 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (24)
    $30.95 each
    1
    Mon, Apr 8
    1
    QtyArrives
    1 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $39.55 each
    $379.50 box of 10
    $37.95 each
    130
    Mon, Apr 8
    130
    QtyArrives
    130 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (7)
    $22.95 each
    102
    Mon, Apr 8
    102
    QtyArrives
    102 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (34)
    $85.65 each
    $329.00 box of 4
    $82.25 each
    67
    Mon, Apr 8
    67
    QtyArrives
    67 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (6)
    $135.95 each
    $391.65 box of 3
    $130.55 each
    3
    Mon, Apr 8
    3
    QtyArrives
    3 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (15)
    $69.95 each
    $268.60 box of 4
    $67.15 each
    8
    Mon, Apr 8
    8
    QtyArrives
    8 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (10)
    $70.45 each
    $270.60 box of 4
    $67.65 each
    24
    Mon, Apr 8
    24
    QtyArrives
    24 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    $114.95 each
    $441.40 box of 4
    $110.35 each
    40
    Mon, Apr 8
    40
    QtyArrives
    40 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (9)
    $164.95 each
    $475.05 box of 3
    $158.35 each
    13
    Mon, Apr 8
    13
    QtyArrives
    13 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $215.95 each
    $414.70 box of 2
    $207.35 each
    Fri, Apr 26 – Fri, May 3
    Arrives
    Fri, Apr 26 – Fri, May 3
    Questions? Call 1-888-757-4774 or
  • Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (7)
    $43.55 each
    $167.40 box of 4
    $41.85 each
    38
    Mon, Apr 8
    38
    QtyArrives
    38 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $37.35 each
    $358.50 box of 10
    $35.85 each
    35
    Mon, Apr 8
    35
    QtyArrives
    35 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • RX-15 Radiant Extrol Expansion Tank (2 Gallon)
    SKU: 140-705
    Brand: Amtrol
    (6)
    $57.75 each
    $221.80 box of 4
    $55.45 each
    25
    Mon, Apr 8
    25
    QtyArrives
    25 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $78.95 each
    $379.75 box of 5
    $75.95 each
    47
    Mon, Apr 8
    47
    QtyArrives
    47 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (3)
    $64.75 each
    $309.75 box of 5
    $61.95 each
    17
    Mon, Apr 8
    17
    QtyArrives
    17 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • 1/2" External NPT Heating Expansion Tank (4.4 Gallon)
    SKU: TK300-30
    Brand: Honeywell-Sparco
    (1)
    $42.45 each
    24
    Mon, Apr 8
    24
    QtyArrives
    24 Mon, Apr 8
    Questions? Call 1-888-757-4774
  • $66.95 each
    11
    Mon, Apr 8
    11
    QtyArrives
    11 Mon, Apr 8
    Questions? Call 1-888-757-4774

Resources

Videos

Articles

  • An expansion tank is designed to relieve pressure in both a potable water and closed heating system. An expansion tank ensures a constant pressure is maintained within the pipes so they do not get damaged from excess pressure.

    An expansion tank has two parts which are divided by a rubber diaphragm. The top portion of the tank is connected to the hot water system and is filled with water. The bottom portion is filled with air set at approximately 12 psi. As the hot water system is turned on or off, pressure increases. As pressure increases, the diaphragm in the expansion tank is pushed down. This compresses the air in the tank, creating more space for excess water to enter. This relieves excess pressure in the system and prevents pipes in the system from being damaged.

    In the event that the diaphragm fails, the tank will completely fill with water. If this occurs, the tank must be replaced immediately. To check if the expansion tank is working properly, simply place your hand on the tank and feel its temperature. The top portion of the tank should feel warm to the touch, and the bottom portion of the tank should be room temperature. If the entire tank is warm, it is likely that the tank has completely filled with hot water.

    Expansion tanks have capacities ranging from 2 gallons to several hundred gallons. To determine the size needed for your system, use the Expansion Tank Sizing Calculator.

    We offer a wide selection of Amtrol, Watts, Cash Acme, and Bell & Gossett expansion tanks to suit all of your plumbing and heating needs.
1-888-757-4774
We're here to help
()
Monday – Thursday
8am–7:45pm ET
Friday
9am–7:45pm ET
  • Product Image

  • Product Image

    Select 2 to 3 items to compare

  • Product Image

    Compare up to 1 more item

Why don't we show the price of this item?

We try to always offer you the lowest prices possible, but some manufacturers require that we only show these low prices once you take further action.

To see the price, simply add the item to your cart or sign in.