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Expansion Tanks

  • THERM-X-TROL ST-5 Expansion Tank Product Image
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    THERM-X-TROL ST-5 Expansion Tank 140N43 THERM-X-TROL ST-5 Expansion Tank
    SKU: 140N43
    Brand: Amtrol
    (48)
    $38.99 each
      Box Up & Save 1%  
    $154.36 box of 4
    $38.59 each
    248
    Fri, Nov 22
    248
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    248 Fri, Nov 22
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  • THERM-X-TROL ST-12 Expansion Tank Product Image
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    THERM-X-TROL ST-12 Expansion Tank 141N43 THERM-X-TROL ST-12 Expansion Tank
    SKU: 141N43
    Brand: Amtrol
    (36)
    $61.45 each
      Box Up & Save 4%  
    $235.80 box of 4
    $58.95 each
    312
    Fri, Nov 22
    312
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    312 Fri, Nov 22
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  • PLT-5, 2.1 Gallon Potable<br>Water Expansion Tank Product Image
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    PLT-5, 2.1 Gallon Potable Water Expansion Tank 0067370 PLT-5, 2.1 Gallon Potable Water Expansion Tank
    SKU: 0067370
    Brand: Watts
    (7)
    $42.99 each
    205
    Fri, Nov 22
    205
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    205 Fri, Nov 22
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  • WX-350 (151S1)<br>119 Gal. WELL-X-TROL Well Tank Product Image
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    WX-350 (151S1) 119 Gal. WELL-X-TROL Well Tank WX-350 WX-350 (151S1) 119 Gal. WELL-X-TROL Well Tank
    SKU: WX-350
    Brand: Amtrol
    (17)
    $1,015.99 each
      Box Up & Save 4%  
    $1,958.30 box of 2
    $979.15 each
    81
    Wed, Nov 27 – Mon, Dec 2
    81
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    81 Wed, Nov 27 – Mon, Dec 2
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  • WX-250 (145S1), 44 Gal. WELL-X-TROL Well Tank Product Image
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    WX-250 (145S1), 44 Gal. WELL-X-TROL Well Tank WX-250 WX-250 (145S1), 44 Gal. WELL-X-TROL Well Tank
    SKU: WX-250
    Brand: Amtrol
    (71)
    $479.99 each
      Box Up & Save 4%  
    $919.98 box of 2
    $459.99 each
    51
    Fri, Nov 22
    51
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    51 Fri, Nov 22
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  • WX-302 (150S1), 86 Gal. WELL-X-TROL Well Tank Product Image
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    WX-302 (150S1), 86 Gal. WELL-X-TROL Well Tank WX-302 WX-302 (150S1), 86 Gal. WELL-X-TROL Well Tank
    SKU: WX-302
    Brand: Amtrol
    (27)
    $708.99 each
      Box Up & Save 4%  
    $1,363.10 box of 2
    $681.55 each
    85
    Wed, Nov 27 – Mon, Dec 2
    85
    QtyArrives
    85 Wed, Nov 27 – Mon, Dec 2
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  • WX-203 (146S30), 32 Gal. WELL-X-TROL Well Tank Product Image
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    WX-203 (146S30), 32 Gal. WELL-X-TROL Well Tank WX-203 WX-203 (146S30), 32 Gal. WELL-X-TROL Well Tank
    SKU: WX-203
    Brand: Amtrol
    (64)
    $375.99 each
      Box Up & Save 2%  
    $735.38 box of 2
    $367.69 each
    38
    Fri, Nov 22
    38
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    38 Fri, Nov 22
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  • WX-255 (149S147), 81 Gal. WELL-X-TROL Well Tank Product Image
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    WX-255 (149S147), 81 Gal. WELL-X-TROL Well Tank WX-255 WX-255 (149S147), 81 Gal. WELL-X-TROL Well Tank
    SKU: WX-255
    Brand: Amtrol
    (28)
    $699.99 each
      Box Up & Save 4%  
    $1,343.98 box of 2
    $671.99 each
    47
    Wed, Nov 27 – Mon, Dec 2
    47
    QtyArrives
    47 Wed, Nov 27 – Mon, Dec 2
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  • WX-202 (144S29), 20 Gal. WELL-X-TROL Well Tank Product Image
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    WX-202 (144S29), 20 Gal. WELL-X-TROL Well Tank WX-202 WX-202 (144S29), 20 Gal. WELL-X-TROL Well Tank
    SKU: WX-202
    Brand: Amtrol
    (51)
    $209.99 each
      Box Up & Save 2%  
    $410.78 box of 2
    $205.39 each
    96
    Fri, Nov 22
    96
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    96 Fri, Nov 22
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  • RP-15HP, 20 Gal<br>Residential Pressuriser Product Image
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    RP-15HP, 20 Gal Residential Pressuriser 2201-39 RP-15HP, 20 Gal Residential Pressuriser
    SKU: 2201-39
    Brand: Amtrol
    (9)
    $1,299.95 each
      Box Up & Save 4%  
    $2,495.90 box of 2
    $1,247.95 each
    20
    Wed, Nov 27 – Mon, Dec 2
    20
    QtyArrives
    20 Wed, Nov 27 – Mon, Dec 2
    Questions? Call 1-888-757-4774
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  • WX-251 (145S10), 62 Gal. WELL-X-TROL Well Tank Product Image
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    WX-251 (145S10), 62 Gal. WELL-X-TROL Well Tank WX-251 WX-251 (145S10), 62 Gal. WELL-X-TROL Well Tank
    SKU: WX-251
    Brand: Amtrol
    (32)
    $699.99 each
      Box Up & Save 4%  
    $1,345.98 box of 2
    $672.99 each
    23
    Wed, Nov 27 – Mon, Dec 2
    23
    QtyArrives
    23 Wed, Nov 27 – Mon, Dec 2
    Questions? Call 1-888-757-4774
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  • RP-10HP, 14 Gal<br>Residential Pressuriser Product Image
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    RP-10HP, 14 Gal Residential Pressuriser 2201-37 RP-10HP, 14 Gal Residential Pressuriser
    SKU: 2201-37
    Brand: Amtrol
    (5)
    $1,025.95 each
      Box Up & Save 2%  
    $2,007.56 box of 2
    $1,003.78 each
    22
    Fri, Nov 22
    22
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    22 Fri, Nov 22
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  • THERM-X-TROL ST-25V Expansion Tank<br>(10.3 Gallon) Product Image
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    THERM-X-TROL ST-25V Expansion Tank (10.3 Gallon) 143N164 THERM-X-TROL ST-25V Expansion Tank (10.3 Gallon)
    SKU: 143N164
    Brand: Amtrol
    (7)
    $139.99 each
      Box Up & Save 4%  
    $404.97 box of 3
    $134.99 each
    73
    Fri, Nov 22
    73
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    73 Fri, Nov 22
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  • WX-202XL (144S240)<br>26 Gal. WELL-X-TROL<br>Well Tank Product Image
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    WX-202XL (144S240) 26 Gal. WELL-X-TROL Well Tank WX-202XL WX-202XL (144S240) 26 Gal. WELL-X-TROL Well Tank
    SKU: WX-202XL
    Brand: Amtrol
    (42)
    $262.99 each
      Box Up & Save 4%  
    $505.98 box of 2
    $252.99 each
    42
    Fri, Nov 22
    42
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    42 Fri, Nov 22
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  • WX-205 (147S44)<br>34 Gal. WELL-X-TROL Product Image
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    WX-205 (147S44) 34 Gal. WELL-X-TROL WX-205 WX-205 (147S44) 34 Gal. WELL-X-TROL
    SKU: WX-205
    Brand: Amtrol
    (20)
    $405.99 each
      Box Up & Save 2%  
    $794.38 box of 2
    $397.19 each
    48
    Fri, Nov 22
    48
    QtyArrives
    48 Fri, Nov 22
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  • RP-25HP, 34 Gal<br>Residential Pressuriser Product Image
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    RP-25HP, 34 Gal Residential Pressuriser 2201-28 RP-25HP, 34 Gal Residential Pressuriser
    SKU: 2201-28
    Brand: Amtrol
    (1)
    $1,779.95 each
    8
    Wed, Nov 27 – Mon, Dec 2
    8
    QtyArrives
    8 Wed, Nov 27 – Mon, Dec 2
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  • WX-252 (145S20), 86 Gal. WELL-X-TROL Well Tank Product Image
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    WX-252 (145S20), 86 Gal. WELL-X-TROL Well Tank WX-252 WX-252 (145S20), 86 Gal. WELL-X-TROL Well Tank
    SKU: WX-252
    Brand: Amtrol
    (6)
    $949.99 each
      Box Up & Save 4%  
    $1,823.98 box of 2
    $911.99 each
    28
    Wed, Nov 27 – Mon, Dec 2
    28
    QtyArrives
    28 Wed, Nov 27 – Mon, Dec 2
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  • WX-250 (145S1), 44 Gal<br>WELL-X-TROL Well Tank<br>w/ Durabase Stand Product Image
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    WX-250 (145S1), 44 Gal WELL-X-TROL Well Tank w/ Durabase Stand WX-250D WX-250 (145S1), 44 Gal WELL-X-TROL Well Tank w/ Durabase Stand
    SKU: WX-250D
    Brand: Amtrol
    (6)
    $509.99 each
    14
    Fri, Nov 22
    14
    QtyArrives
    14 Fri, Nov 22
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  • WX-255 (149S147), 81 Gal<br>WELL-X-TROL Well Tank<br>w/ Durabase Stand Product Image
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    WX-255 (149S147), 81 Gal WELL-X-TROL Well Tank w/ Durabase Stand WX-255D WX-255 (149S147), 81 Gal WELL-X-TROL Well Tank w/ Durabase Stand
    SKU: WX-255D
    Brand: Amtrol
    (2)
    $759.99 each
    20
    Wed, Nov 27 – Mon, Dec 2
    20
    QtyArrives
    20 Wed, Nov 27 – Mon, Dec 2
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  • THERM-X-SPAN T-5 Expansion Tank<br>(2 Gallon) Product Image
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    THERM-X-SPAN T-5 Expansion Tank (2 Gallon) 140735 THERM-X-SPAN T-5 Expansion Tank (2 Gallon)
    SKU: 140735
    Brand: Amtrol
    (13)
    $31.99 each
      Box Up & Save 4%  
    $122.76 box of 4
    $30.69 each
    160
    Fri, Nov 22
    160
    QtyArrives
    160 Fri, Nov 22
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  • WX1-302 (150S92)<br>86 Gal. WELL-X-TROL<br>Well-X1 Well Tank (Blue) Product Image
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    WX1-302 (150S92) 86 Gal. WELL-X-TROL Well-X1 Well Tank (Blue) WX1-302 WX1-302 (150S92) 86 Gal. WELL-X-TROL Well-X1 Well Tank (Blue)
    SKU: WX1-302
    Brand: Amtrol
    (3)
    $1,024.99 each
    7
    Wed, Nov 27 – Mon, Dec 2
    7
    QtyArrives
    7 Wed, Nov 27 – Mon, Dec 2
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  • WX-101 (140PR1)<br>2 Gal. WELL-X-TROL<br>In-Line Well Tank Product Image
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    WX-101 (140PR1) 2 Gal. WELL-X-TROL In-Line Well Tank WX-101 WX-101 (140PR1) 2 Gal. WELL-X-TROL In-Line Well Tank
    SKU: WX-101
    Brand: Amtrol
    (14)
    $69.99 each
      Box Up & Save 4%  
    $267.96 box of 4
    $66.99 each
    75
    Fri, Nov 22
    75
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    75 Fri, Nov 22
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  • THERM-X-TROL ST-8 Expansion Tank Product Image
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    THERM-X-TROL ST-8 Expansion Tank 140N738 THERM-X-TROL ST-8 Expansion Tank
    SKU: 140N738
    Brand: Amtrol
    (13)
    $49.99 each
      Box Up & Save 4%  
    $191.96 box of 4
    $47.99 each
    164
    Fri, Nov 22
    164
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    164 Fri, Nov 22
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  • WX-203 (146S30), 32 Gal<br>WELL-X-TROL Well Tank<br>w/ Durabase Stand Product Image
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    WX-203 (146S30), 32 Gal WELL-X-TROL Well Tank w/ Durabase Stand WX-203D WX-203 (146S30), 32 Gal WELL-X-TROL Well Tank w/ Durabase Stand
    SKU: WX-203D
    Brand: Amtrol
    (4)
    $399.99 each
    3
    Fri, Nov 22
    3
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    3 Fri, Nov 22
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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 Size Calculator located here.

    We offer a wide selection of
    Therm-X-Trol and Well-X-Trol expansion tanks to suit all of your plumbing and heating needs.

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