Name: EASTMAN 4.5-Gallon Thermal Expansion Tank
Brand: EASTMAN
SKU: 5000087245
Price: 59.98 USD
Availability: InStock
Rating: 4.7 (460 reviews)

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The Eastman 4.5-Gallon Thermal Expansion Tank provides a secure connection to water heaters that prevents dangerous build-ups of pressure. This water heater expansion tank stops hot water from backflowing into the cold water line and prevents hot water from escaping through the pressure relief valve and onto the floor. Constant fluctuations in water pressure can be dangerous and they can damage the water heater, properly installing a thermal expansion tank can solve all these issues. This product comes with a 6-year limited warranty and is factory pre-charged at 40 psi. Complies with NSF-61 and Lead-Free guidelines. UPC approved.

For use in 30 to 160 gallon water heater tanks
Prevents dangerous pressure build-ups
For installation on residential water heaters
Built with a butyl rubber diaphragm
3/4-In MIP connection; 4.5 gallon capacity
Factory pre-charged at 40 PSI
Maximum operating temperature: 210-degrees F
Maximum working pressure: 150 psi
Dimensions: 16 inch L X 11 inch W X 10.9 inch H

General
Color/Finish Family	White	Connection Type	MIP
Package Quantity	1	Material	Steel

Dimensions
Height (Inches)	10.9	Weight (When Empty) (lbs.)	9.04
Tank Discharge Size (Inches)	0.075	Water Connection Size	3/4-in
Diameter (Inches)	11	Thread Size (Inches)	0.75
Tank Capacity (Gallons)	4.5	Length (Inches)	16

Features
Pressure Relief Valve	Yes	Max Operating Temperature (Fahrenheit)	210
Lowe's Exclusive	Yes	Maximum Working Pressure (PSI)	150

Compatibility
Brand/Model Compatibility	Universal

Certifications
CA Residents: Prop 65 Warning(s)	Prop 65 WARNING(S) -

Miscellaneous
UNSPSC	24111800

Check out the Best Selling Expansion Tanks on Lowes.com

Review

4.7 out of 5

460 Reviews

94% Recommend this product

Ratings may include incentivized customer reviews.

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+ 13

What Customers Are Saying

Customers overwhelmingly praise this expansion tank for straightforward installation, reliable performance, and solid build quality. Most highlight the quick setup process taking under 20 minutes with minimal tools, even for those without plumbing experience. Reviewers consistently report it performs its core function effectively—reducing water hammer and managing pressure spikes—with the pre-charged 40 PSI setting saving additional effort. The tank is described as well-made and durable, with many referencing previous units lasting over 19 years. Customers appreciate the strong value and code compliance benefits. A few isolated issues include minor dents, sharp mounting edges, and unclear instructions, though these are uncommon and do not diminish overall satisfaction.

Customer review summary generated by AI, including incentivized reviews.

460 Customer Reviews

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Good product

Would Recommend

This is a great product and installation was easy

Jason GSeptember 28, 2026
Verified Purchaser

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2-Gallon Thermal Expansion Tank

Would Recommend

The 2-Gallon Thermal Expansion Tank is a well-made, reliable product that performs exactly as expected. It feels sturdy and durable, installs easily, and provides excellent pressure control for the water system. Overall, it’s a quality product that offers great performance and peace of mind.

TMappSeptember 18, 2026
From 2-Gallon Thermal Expansion Tank Verified Purchaser

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Stop pressure/temperature relief drips.

Would Recommend

Install one of these to prevent your pressure and temperature relief drips. It's necessary.

CoolersOnlineSeptember 16, 2026
From 2-Gallon Thermal Expansion Tank Verified Purchaser

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		Name	Current Item EASTMAN4.5-Gallon Thermal Expansion Tank
		Ratings	459
		CA Residents: Prop 65 Warning(s)
		Height (Inches)	10.9
		Tank Capacity (Gallons)	4.5
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