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Expansion Tanks

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Expansion Tanks

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Lead Content Warning

Do not use this item for any installation or repair of potable water applications. This product does not comply with the "Safe Drinking Water Act," which requires that products meet low-lead standards in order to be used in systems providing water for human consumption (drinking or cooking). This item is for non-potable (non-human consumption) water applications only.

Lead Content Warning

This product does not comply with the Safe Drinking Water Act, which requires that products used in any system providing water for human consumption (drinking or cooking) to meet low-lead standards. Please check the box below to confirm you are aware that this item is for non-potable water applications only.

This product will NOT be used in the installation or repair of a potable water (human consumption) application.

You must agree to this statement in order to purchase this product.

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This Item is Non-Returnable

When you order this item, we then special order it for you from the manufacturer. Therefore, our standard return policy does not apply to this item. Manufacturer's warranty still applies.

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Certification Necessary

FlashShield is to be installed only by a licensed plumber/HVAC installer that has successfully completed the Gastite/FlashShield certification test.

By checking this box I am acknowledging that I have successfully completed the Gastite/FlashShield certification and I hold a valid Gastite/FlashShield certification card.

You must agree to this statement in order to purchase this product.

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Warning

This product must be installed by a qualified/licensed contractor and set up with properly calibrated combustion test equipment. Failure to comply with this could result in substantial property damage, severe personal injury or death.

By checking this box I am verifying that this product will be installed by a qualified/licensed contractor and will be set up with properly calibrated combustion test equipment.

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THERM-X-TROL ST-5 Expansion Tank

SKU: 140N43

Brand: Amtrol

(44)

$45.95 each

$176.60 box of 4

$44.15 each

233

Thu, Feb 28

233

Qty Arrives

233 Thu, Feb 28

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THERM-X-TROL ST-12 Expansion Tank

SKU: 141N43

Brand: Amtrol

(33)

$61.45 each

$235.80 box of 4

$58.95 each

181

Thu, Feb 28

181

Qty Arrives

181 Thu, Feb 28

Questions? Call 1-888-757-4774
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11" HydroClaw Expansion Tank Support Bracket

SKU: HC11-A

Brand: Storm King Enterprises

(37)

$40.95 each

58

Thu, Feb 28

58

Qty Arrives

58 Thu, Feb 28

Questions? Call 1-888-757-4774
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3/4" Threaded Spring Loaded Check Valve, Lead Free

SKU: SLCT075

Brand: Bluefin

(27)

We only have available.

Please enter a quantity of or less to add to cart.

We have a similar product available - View Replacement

$9.15 each

$91.80 box of 12

$7.65 each

924

Thu, Feb 28

924

Qty Arrives

924 Thu, Feb 28

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1" Threaded Spring Loaded Check Valve Lead Free

SKU: SLCT100

Brand: Bluefin

(27)

We only have available.

Please enter a quantity of or less to add to cart.

We have a similar product available - View Replacement

$11.85 each

$98.50 box of 10

$9.85 each

563

Thu, Feb 28

563

Qty Arrives

563 Thu, Feb 28

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PLT-5, 2.1 Gallon Potable Water Expansion Tank

SKU: 0067370

Brand: Watts

(4)

$39.55 each

106

Thu, Feb 28

106

Qty Arrives

106 Thu, Feb 28

Questions? Call 1-888-757-4774
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QuickStrap Expansion Tank Mounting Bracket (2.5 Gal. Capacity)

SKU: QS-5

Brand: Holdrite

(24)

$14.85 each

$142.50 box of 10

$14.25 each

135

Thu, Feb 28

135

Qty Arrives

135 Thu, Feb 28

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QuickStrap Expansion Tank Mounting Bracket (5 Gal. Capacity)

SKU: QS-12

Brand: Holdrite

(27)

$17.25 each

$165.50 box of 10

$16.55 each

135

Thu, Feb 28

135

Qty Arrives

135 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-250 (145S1), 44 Gal. WELL-X-TROL Well Tank

SKU: WX-250

Brand: Amtrol

(66)

$515.95 each

$990.70 box of 2

$495.35 each

141

Thu, Feb 28

141

Qty Arrives

141 Thu, Feb 28

Questions? Call 1-888-757-4774
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1/2" Threaded Spring Loaded Check Valve, Lead Free

SKU: SLCT050

Brand: Bluefin

(27)

We only have available.

Please enter a quantity of or less to add to cart.

We have a similar product available - View Replacement

$6.15 each

$77.25 box of 15

$5.15 each

969

Thu, Feb 28

969

Qty Arrives

969 Thu, Feb 28

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8" HydroClaw Expansion Tank Support Bracket

SKU: HC8-B

Brand: Storm King Enterprises

(23)

$30.95 each

26

Thu, Feb 28

26

Qty Arrives

26 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-203 (146S30), 32 Gal. WELL-X-TROL Well Tank

SKU: WX-203

Brand: Amtrol

(60)

$424.95 each

$815.90 box of 2

$407.95 each

112

Thu, Feb 28

112

Qty Arrives

112 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-202 (144S29), 20 Gal. WELL-X-TROL Well Tank

SKU: WX-202

Brand: Amtrol

(46)

$229.95 each

$441.50 box of 2

$220.75 each

109

Thu, Feb 28

109

Qty Arrives

109 Thu, Feb 28

Questions? Call 1-888-757-4774
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Pressure Switch, 40/60 PSI, 10 Amp, DPST

SKU: 9013FSG2J24

Brand: Square D

(10)

$14.75 each

144

Thu, Feb 28

144

Qty Arrives

144 Thu, Feb 28

Questions? Call 1-888-757-4774
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THERM-X-SPAN T-5 Expansion Tank (2 Gallon)

SKU: 140735

Brand: Amtrol

(12)

$37.25 each

$143.00 box of 4

$35.75 each

140

Thu, Feb 28

140

Qty Arrives

140 Thu, Feb 28

Questions? Call 1-888-757-4774
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THERM-X-TROL ST-8 Expansion Tank

SKU: 140N738

Brand: Amtrol

(11)

$55.55 each

$213.40 box of 4

$53.35 each

48

Thu, Feb 28

48

Qty Arrives

48 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-202XL (144S240) 26 Gal. WELL-X-TROL Well Tank

SKU: WX-202XL

Brand: Amtrol

(38)

$279.95 each

$537.50 box of 2

$268.75 each

30

Thu, Feb 28

30

Qty Arrives

30 Thu, Feb 28

Questions? Call 1-888-757-4774
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Water Pump Pressure Switch, 30/50 PSI, DPST

SKU: 9013FSG2J21

Brand: Square D

(1)

$12.25 each

93

Thu, Feb 28

93

Qty Arrives

93 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-302 (150S1), 86 Gal. WELL-X-TROL Well Tank

SKU: WX-302

Brand: Amtrol

(25)

$709.95 each

$1,363.10 box of 2

$681.55 each

44

Mon, Mar 4 – Wed, Mar 6

44

Qty Arrives

44 Mon, Mar 4 – Wed, Mar 6

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WX-101 (140PR1) 2 Gal. WELL-X-TROL In-Line Well Tank

SKU: WX-101

Brand: Amtrol

(12)

$72.95 each

$280.20 box of 4

$70.05 each

47

Thu, Feb 28

47

Qty Arrives

47 Thu, Feb 28

Questions? Call 1-888-757-4774
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THERM-X-TROL ST-25V Expansion Tank (10.3 Gallon)

SKU: 143N164

Brand: Amtrol

(6)

$149.95 each

$431.85 box of 3

$143.95 each

88

Thu, Feb 28

88

Qty Arrives

88 Thu, Feb 28

Questions? Call 1-888-757-4774
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1-1/4" Threaded Spring Loaded Check Valve, Lead Free

SKU: SLCT125

Brand: Bluefin

(27)

We only have available.

Please enter a quantity of or less to add to cart.

We have a similar product available - View Replacement

$21.25 each

$142.00 box of 8

$17.75 each

224

Thu, Feb 28

224

Qty Arrives

224 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-255 (149S147), 81 Gal. WELL-X-TROL Well Tank

SKU: WX-255

Brand: Amtrol

(27)

$759.95 each

$1,459.10 box of 2

$729.55 each

45

Mon, Mar 4 – Wed, Mar 6

45

Qty Arrives

45 Mon, Mar 4 – Wed, Mar 6

Questions? Call 1-888-757-4774
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WX-350 (151S1) 119 Gal. WELL-X-TROL Well Tank

SKU: WX-350

Brand: Amtrol

(17)

$1,019.95 each

$1,958.30 box of 2

$979.15 each

23

Mon, Mar 4 – Wed, Mar 6

23

Qty Arrives

23 Mon, Mar 4 – Wed, Mar 6

Questions? Call 1-888-757-4774
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DuraBase Tank Spacer for 22" & 26" Steel Stand

SKU: DURABASE-22

Brand: Amtrol

(6)

$27.65 each

$265.50 box of 10

$26.55 each

38

Thu, Feb 28

38

Qty Arrives

38 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-251 (145S10), 62 Gal. WELL-X-TROL Well Tank

SKU: WX-251

Brand: Amtrol

(32)

$775.95 each

$1,489.90 box of 2

$744.95 each

28

Mon, Mar 4 – Wed, Mar 6

28

Qty Arrives

28 Mon, Mar 4 – Wed, Mar 6

Questions? Call 1-888-757-4774
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THERM-X-SPAN T-12 Expansion Tank (4.4 Gallon)

SKU: 141363

Brand: Amtrol

(3)

$47.75 each

$183.40 box of 4

$45.85 each

71

Thu, Feb 28

71

Qty Arrives

71 Thu, Feb 28

Questions? Call 1-888-757-4774
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WX-102 (141PR1) 4.4 Gal. WELL-X-TROL In-Line Well Tank

SKU: WX-102

Brand: Amtrol

(12)

$109.95 each

$422.20 box of 4

$105.55 each

19

Thu, Feb 28

19

Qty Arrives

19 Thu, Feb 28

Questions? Call 1-888-757-4774
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1-1/2" Threaded Spring Loaded Check Valve, Lead Free

SKU: SLCT150

Brand: Bluefin

(27)

We only have available.

Please enter a quantity of or less to add to cart.

We have a similar product available - View Replacement

$24.95 each

$104.75 box of 5

$20.95 each

136

Thu, Feb 28

136

Qty Arrives

136 Thu, Feb 28

Questions? Call 1-888-757-4774
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Expansion Tank Support Kit w/ 32.5" Band for 2 Gallon Tanks

SKU: 598-0210

Brand: Sioux Chief

(1)

$3.91 each

$37.20 box of 10

$3.72 each

Wed, Mar 13 – Wed, Mar 20

Arrives

Wed, Mar 13 – Wed, Mar 20

Questions? Call 1-888-757-4774 or Live Chat

Qty	Arrives
233	Thu, Feb 28

Qty	Arrives
181	Thu, Feb 28

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58	Thu, Feb 28

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924	Thu, Feb 28

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563	Thu, Feb 28

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106	Thu, Feb 28

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135	Thu, Feb 28

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135	Thu, Feb 28

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141	Thu, Feb 28

Qty	Arrives
969	Thu, Feb 28

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26	Thu, Feb 28

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112	Thu, Feb 28

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109	Thu, Feb 28

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144	Thu, Feb 28

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140	Thu, Feb 28

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48	Thu, Feb 28

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30	Thu, Feb 28

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93	Thu, Feb 28

Qty	Arrives
44	Mon, Mar 4 – Wed, Mar 6

Qty	Arrives
47	Thu, Feb 28

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88	Thu, Feb 28

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224	Thu, Feb 28

Qty	Arrives
45	Mon, Mar 4 – Wed, Mar 6

Qty	Arrives
23	Mon, Mar 4 – Wed, Mar 6

Qty	Arrives
38	Thu, Feb 28

Qty	Arrives
28	Mon, Mar 4 – Wed, Mar 6

Qty	Arrives
71	Thu, Feb 28

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19	Thu, Feb 28

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136	Thu, Feb 28

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Wed, Mar 13 – Wed, Mar 20

Resources

Videos

How Expansion Tanks Work

Calculators

Expansion Tank Size Calculator

Articles

More About Expansion Tanks

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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