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Expansion Tanks

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
    (58)
    $39.00 each
    547
    Tue, Dec 8
    547
    QtyArrives
    547 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (45)
    $46.00 each
    242
    Tue, Dec 8
    242
    QtyArrives
    242 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (11)
    $36.59 each
    170
    Tue, Dec 8
    170
    QtyArrives
    170 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (18)
    $1,015.98 each
    Wed, Feb 24 – Fri, Mar 26
    Arrives
    Wed, Feb 24 – Fri, Mar 26
    Questions? Call 1-888-757-4774 or
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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
    (82)
    $499.98 each
    Fri, Feb 19 – Fri, Mar 19
    Arrives
    Fri, Feb 19 – Fri, Mar 19
    Questions? Call 1-888-757-4774 or
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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
    (31)
    $752.20 each
    Wed, Feb 24 – Fri, Mar 26
    Arrives
    Wed, Feb 24 – Fri, Mar 26
    Questions? Call 1-888-757-4774 or
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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
    (85)
    $412.95 each
    Fri, Feb 19 – Fri, Mar 19
    Arrives
    Fri, Feb 19 – Fri, Mar 19
    Questions? Call 1-888-757-4774 or
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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
    (33)
    $675.59 each
    35
    Mon, Dec 14 – Wed, Dec 16
    35
    QtyArrives
    35 Mon, Dec 14 – Wed, Dec 16
    Questions? Call 1-888-757-4774
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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
    (66)
    $217.99 each
    Fri, Feb 19 – Fri, Mar 19
    Arrives
    Fri, Feb 19 – Fri, Mar 19
    Questions? Call 1-888-757-4774 or
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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
    (11)
    $1,129.95 each
    25
    Mon, Dec 14 – Wed, Dec 16
    25
    QtyArrives
    25 Mon, Dec 14 – Wed, Dec 16
    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)
    $740.70 each
    Wed, Feb 24 – Fri, Mar 26
    Arrives
    Wed, Feb 24 – Fri, Mar 26
    Questions? Call 1-888-757-4774 or
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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
    (8)
    $1,157.65 each
    12
    Tue, Dec 8
    12
    QtyArrives
    12 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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)
    $133.62 each
    133
    Tue, Dec 8
    133
    QtyArrives
    133 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (48)
    $317.75 each
    Fri, Feb 19 – Fri, Mar 19
    Arrives
    Fri, Feb 19 – Fri, Mar 19
    Questions? Call 1-888-757-4774 or
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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
    (24)
    $415.21 each
    5
    Tue, Dec 8
    5
    QtyArrives
    5 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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)
    $1,702.19 each
    5
    Mon, Dec 14 – Wed, Dec 16
    5
    QtyArrives
    5 Mon, Dec 14 – Wed, Dec 16
    Questions? Call 1-888-757-4774
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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
    (10)
    $1,103.01 each
    Wed, Feb 24 – Fri, Mar 26
    Arrives
    Wed, Feb 24 – Fri, Mar 26
    Questions? Call 1-888-757-4774 or
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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
    (10)
    $592.50 each
    Fri, Feb 19 – Fri, Mar 19
    Arrives
    Fri, Feb 19 – Fri, Mar 19
    Questions? Call 1-888-757-4774 or
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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
    (5)
    $742.81 each
    4
    Mon, Dec 14 – Wed, Dec 16
    4
    QtyArrives
    4 Mon, Dec 14 – Wed, Dec 16
    Questions? Call 1-888-757-4774
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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
    (18)
    $32.65 each
    177
    Tue, Dec 8
    177
    QtyArrives
    177 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (5)
    $953.92 each
    5
    Mon, Dec 14 – Wed, Dec 16
    5
    QtyArrives
    5 Mon, Dec 14 – Wed, Dec 16
    Questions? Call 1-888-757-4774
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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
    (18)
    $80.25 each
    90
    Tue, Dec 8
    90
    QtyArrives
    90 Tue, Dec 8
    Questions? Call 1-888-757-4774
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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
    (6)
    $419.93 each
    1
    Tue, Dec 8
    1
    QtyArrives
    1 Tue, Dec 8
    Questions? Call 1-888-757-4774
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  • WX-350 (151S1), 119 Gal<br>WELL-X-TROL Well Tank<br>w/ Durabase Stand Product Image
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    WX-350 (151S1), 119 Gal WELL-X-TROL Well Tank w/ Durabase Stand WX-350D WX-350 (151S1), 119 Gal WELL-X-TROL Well Tank w/ Durabase Stand
    SKU: WX-350D
    Brand: Amtrol
    (2)
    $1,115.99 each
    Wed, Feb 24 – Fri, Mar 26
    Arrives
    Wed, Feb 24 – Fri, Mar 26
    Questions? Call 1-888-757-4774 or
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FAQs, Manuals & Videos
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Resources

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  • 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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