Trade Professional? Apply to become a TradeMaster!

Expansion Tanks

  • #30 Extrol Expansion Tank (4.4 Gallon) Product Image
    Add to List
    Add to List
    #30 Extrol Expansion Tank (4.4 Gallon) 102-1 #30 Extrol Expansion Tank (4.4 Gallon)
    SKU: 102-1
    Brand: Amtrol
    (245)
    $33.49 each
      Box Up & Save 4%  
    $128.76 box of 4
    $32.19 each
    2,114
    Mon, Dec 23
    2,114
    QtyArrives
    2,114 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • #15 Extrol Expansion Tank (2 Gallon) Product Image
    Add to List
    Add to List
    #15 Extrol Expansion Tank (2 Gallon) 101-1 #15 Extrol Expansion Tank (2 Gallon)
    SKU: 101-1
    Brand: Amtrol
    (65)
    $29.29 each
      Box Up & Save 4%  
    $112.76 box of 4
    $28.19 each
    1,164
    Mon, Dec 23
    1,164
    QtyArrives
    1,164 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • #60 Extrol Expansion Tank (7.6 Gallon) Product Image
    Add to List
    Add to List
    #60 Extrol Expansion Tank (7.6 Gallon) 103-1 #60 Extrol Expansion Tank (7.6 Gallon)
    SKU: 103-1
    Brand: Amtrol
    (32)
    $65.85 each
      Box Up & Save 4%  
    $253.00 box of 4
    $63.25 each
    642
    Mon, Dec 23
    642
    QtyArrives
    642 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain Product Image
    Add to List
    Add to List
    1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain 41672 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain
    Contains Lead
    SKU: 41672
    Brand: Webstone
    (10)
    $22.29 each
      Box Up & Save 4%  
    $213.90 box of 10
    $21.39 each
    330
    Mon, Dec 23
    830
    QtyArrives
    330 Mon, Dec 23
    500 Tue, Dec 24 – Thu, Dec 26
    Questions? Call 1-888-757-4774
    Add to List
  • 11" HydroClaw Expansion Tank Support Bracket Product Image
    Add to List
    Add to List
    11" HydroClaw Expansion Tank Support Bracket HC11-A 11" HydroClaw Expansion Tank Support Bracket
    SKU: HC11-A
    Brand: Storm King Enterprises
    (48)
    $40.95 each
    224
    Mon, Dec 23
    224
    QtyArrives
    224 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • QuickStrap Expansion Tank Mounting Bracket <br>(2.5 Gal. Capacity) Product Image
    Add to List
    Add to List
    QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity) QS-5 QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity)
    SKU: QS-5
    Brand: Holdrite
    (28)
    $14.99 each
      Box Up & Save 4%  
    $143.90 box of 10
    $14.39 each
    168
    Mon, Dec 23
    168
    QtyArrives
    168 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • QuickStrap Expansion Tank Mounting Bracket<br>(5 Gal. Capacity) Product Image
    Add to List
    Add to List
    QuickStrap Expansion Tank Mounting Bracket (5 Gal. Capacity) QS-12 QuickStrap Expansion Tank Mounting Bracket (5 Gal. Capacity)
    SKU: QS-12
    Brand: Holdrite
    (27)
    $16.99 each
      Box Up & Save 4%  
    $162.90 box of 10
    $16.29 each
    164
    Mon, Dec 23
    164
    QtyArrives
    164 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Flexconsole - 1/2" x 1/2" NPT - Steel (Red) Product Image
    Add to List
    Add to List
    Flexconsole - 1/2" x 1/2" NPT - Steel (Red) 97975 Flexconsole - 1/2" x 1/2" NPT - Steel (Red)
    Contains Lead
    SKU: 97975
    Brand: Flamco
    (8)
    $22.95 each
    158
    Mon, Dec 23
    158
    QtyArrives
    158 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • 8" HydroClaw Expansion Tank Support Bracket Product Image
    Add to List
    Add to List
    8" HydroClaw Expansion Tank Support Bracket HC8-B 8" HydroClaw Expansion Tank Support Bracket
    SKU: HC8-B
    Brand: Storm King Enterprises
    (27)
    $30.95 each
    100
    Mon, Dec 23
    100
    QtyArrives
    100 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Model 110 Fill-Trol<br>w/ Valve (4.4 Gallon) Product Image
    Add to List
    Add to List
    Model 110 Fill-Trol w/ Valve (4.4 Gallon) 110-1 Model 110 Fill-Trol w/ Valve (4.4 Gallon)
    SKU: 110-1
    Brand: Amtrol
    (41)
    $75.99 each
      Box Up & Save 4%  
    $291.96 box of 4
    $72.99 each
    129
    Mon, Dec 23
    129
    QtyArrives
    129 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • SX-30V Extrol Expansion Tank (14 Gallon) Product Image
    Add to List
    Add to List
    SX-30V Extrol Expansion Tank (14 Gallon) 118-27 SX-30V Extrol Expansion Tank (14 Gallon)
    SKU: 118-27
    Brand: Amtrol
    (10)
    $129.99 each
      Box Up & Save 4%  
    $374.97 box of 3
    $124.99 each
    107
    Mon, Dec 23
    107
    QtyArrives
    107 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • RX-30 Radiant Extrol Expansion Tank<br>(4.4 Gallon) Product Image
    Add to List
    Add to List
    RX-30 Radiant Extrol Expansion Tank (4.4 Gallon) 141-305 RX-30 Radiant Extrol Expansion Tank (4.4 Gallon)
    SKU: 141-305
    Brand: Amtrol
    (10)
    $62.99 each
      Box Up & Save 5%  
    $239.96 box of 4
    $59.99 each
    12
    Mon, Dec 23
    12
    QtyArrives
    12 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Model 109 Fill-Trol<br>w/ Valve (2 Gallon) Product Image
    Add to List
    Add to List
    Model 109 Fill-Trol w/ Valve (2 Gallon) 109-1 Model 109 Fill-Trol w/ Valve (2 Gallon)
    SKU: 109-1
    Brand: Amtrol
    (18)
    $69.95 each
      Box Up & Save 4%  
    $268.60 box of 4
    $67.15 each
    72
    Mon, Dec 23
    72
    QtyArrives
    72 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • #90 Extrol Expansion Tank (14 Gallon) Product Image
    Add to List
    Add to List
    #90 Extrol Expansion Tank (14 Gallon) 112-1 #90 Extrol Expansion Tank (14 Gallon)
    SKU: 112-1
    Brand: Amtrol
    (11)
    $114.95 each
      Box Up & Save 4%  
    $441.40 box of 4
    $110.35 each
    96
    Mon, Dec 23
    96
    QtyArrives
    96 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • SX-40V Extrol Expansion Tank (20 Gallon) Product Image
    Add to List
    Add to List
    SX-40V Extrol Expansion Tank (20 Gallon) 118-78 SX-40V Extrol Expansion Tank (20 Gallon)
    SKU: 118-78
    Brand: Amtrol
    (11)
    $164.95 each
      Box Up & Save 4%  
    $475.05 box of 3
    $158.35 each
    64
    Mon, Dec 23
    64
    QtyArrives
    64 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • ETX-30, Non-Potable Water Expansion Tank<br>(4.5 Gallon) Product Image
    Add to List
    Add to List
    ETX-30, Non-Potable Water Expansion Tank (4.5 Gallon) 0066606 ETX-30, Non-Potable Water Expansion Tank (4.5 Gallon)
    SKU: 0066606
    Brand: Watts
    (13)
    $37.99 each
      Box Up & Save 4%  
    $364.90 box of 10
    $36.49 each
    59
    Mon, Dec 23
    59
    QtyArrives
    59 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • SX-60V Extrol Expansion Tank (32 Gallon) Product Image
    Add to List
    Add to List
    SX-60V Extrol Expansion Tank (32 Gallon) 118-79 SX-60V Extrol Expansion Tank (32 Gallon)
    SKU: 118-79
    Brand: Amtrol
    (1)
    $205.99 each
      Box Up & Save 2%  
    $403.00 box of 2
    $201.50 each
    47
    Mon, Dec 23
    47
    QtyArrives
    47 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • 1/2" External NPT<br>Heating Expansion<br>Tank (4.4 Gallon) Product Image
    Add to List
    Add to List
    1/2" External NPT Heating Expansion Tank (4.4 Gallon) TK300-30 1/2" External NPT Heating Expansion Tank (4.4 Gallon)
    SKU: TK300-30
    Brand: Honeywell-Sparco
    (3)
    $42.45 each
    84
    Mon, Dec 23
    84
    QtyArrives
    84 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • RX-15 Radiant Extrol Expansion Tank (2 Gallon) Product Image
    Add to List
    Add to List
    RX-15 Radiant Extrol Expansion Tank (2 Gallon) 140-705 RX-15 Radiant Extrol Expansion Tank (2 Gallon)
    SKU: 140-705
    Brand: Amtrol
    (6)
    $57.75 each
      Box Up & Save 4%  
    $221.80 box of 4
    $55.45 each
    11
    Mon, Dec 23
    11
    QtyArrives
    11 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White) Product Image
    Add to List
    Add to List
    Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White) 97976-FLAMCO Flexconsole - 3/4" x 1/2" NPT - Stainless Steel (White)
    SKU: 97976-FLAMCO
    Brand: Flamco
    $66.95 each
    27
    Mon, Dec 23
    27
    QtyArrives
    27 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Fill Control Valve Product Image
    Add to List
    Add to List
    Fill Control Valve 109-15 Fill Control Valve
    SKU: 109-15
    Brand: Amtrol
    (9)
    $43.55 each
      Box Up & Save 4%  
    $167.40 box of 4
    $41.85 each
    40
    Mon, Dec 23
    40
    QtyArrives
    40 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG) Product Image
    Add to List
    Add to List
    1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG) H-44672 1/2" Pro-Pal Full Port Brass Ball Valve w/ Hi-Flow Hose Drain - FIP x FIP (600 WOG)
    SKU: H-44672
    Brand: Webstone
    $22.99 each
      Box Up & Save 4%  
    $219.90 box of 10
    $21.99 each
    82
    Mon, Dec 23
    416
    QtyArrives
    82 Mon, Dec 23
    334 Tue, Dec 24 – Thu, Dec 26
    Questions? Call 1-888-757-4774
    Add to List
  • RBFF, 1/2" Residential Boiler Fill Fitting Product Image
    Add to List
    Add to List
    RBFF, 1/2" Residential Boiler Fill Fitting 0386466 RBFF, 1/2" Residential Boiler Fill Fitting
    SKU: 0386466
    Brand: Watts
    (4)
    $66.99 each
      Box Up & Save 4%  
    $320.45 box of 5
    $64.09 each
    32
    Mon, Dec 23
    32
    QtyArrives
    32 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List
  • Model 110 Fill-Trol<br>Tank Only (4.4 Gallon) Product Image
    Add to List
    Add to List
    Model 110 Fill-Trol Tank Only (4.4 Gallon) 110-002 Model 110 Fill-Trol Tank Only (4.4 Gallon)
    SKU: 110-002
    Brand: Amtrol
    (11)
    $70.55 each
      Box Up & Save 4%  
    $271.00 box of 4
    $67.75 each
    23
    Mon, Dec 23
    23
    QtyArrives
    23 Mon, Dec 23
    Questions? Call 1-888-757-4774
    Add to List

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, and Bell & Gossett expansion tanks to suit all of your plumbing and heating needs.

NEED HELP?

888-757-4774
()
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.