Does a water heater blanket save money?

On older tanks yes — typically $20–$60 a year, paying back in under 12 months. Newer high-efficiency tanks gain little.

What thickness of pipe insulation do I need?

3/8 inch wall in conditioned spaces, 1/2 to 1 inch in unheated crawl spaces, attics and garages.

Can I insulate a gas water heater?

Yes, but keep the top, flue, burner access, thermostat and relief valve completely clear.

Buying Guides

Best Pipe and Water Heater Insulation

Two of the fastest paybacks in the house: a $25 pipe insulation run and a $40 water heater blanket, both installable in under an hour.

Updated January 2026 · about 5 min read

Popular picks on Amazon

Pipe Insulation Foam

Duck Brand Foam Pipe Covers, Pipe Insulation Foam Tubes for Hot and Cold Water Pipes, Pre Slit and Self Sealing Adhesive Edge, 0.75 in. x 1 Ft., 6 Sticks Per Package, 6 Feet Total, Black

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CARGEN 1/2" ID Foam Pipe Insulation Fits 1/2" OD Copper & PEX Water Pipes | For 1/2" OD PEX, PE, copper & water lines; 3/8" wall x 6FT, helps protect against freezing and condensation

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Pipe Insulation Tubing (1-1/2" x 3/8" x 6FT), 1-1/2" ID Pipe Insulation Foam Tubing, Guitar Stand Foam Tubing, Hollow Tube Covers, Gym Handle Protectors and Roof Racks, Etc.

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Water Heater Insulation Blanket

Frost King SP57/11C All Season Water Heater Insulation Blanket, 3” Thick x 48” x 75”, R10

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AES Industries Water Heater Blanket Jacket Insulation Non Fiberglass Fits 40 50 60 and 80 Gallon Tank R8

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76"x48" Water Heater Insulation Blanket for 40-80 Gallon Pre-Oxidized Fiber | Soft tight fit, easy cut & install, includes 25.5" round top spacer & 16FT foil tape for complete installation

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Foil Tape Hvac Insulation

Romeda Aluminum Foil Tape, 2 inch x 65 Feet Foil Tape (3.9 mil), Silver Insulation Adhesive Metal Tape, High Temperature Heavy Duty HVAC Tapes for Ductwork, Dryer Vent, HVAC

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Aluminum Foil Duct Tape Heavy Duty Waterproof, Premium Silver Metal HVAC Heat Tapes (2"*65Feet,3.9mil), High Temperature, Dryer Vent Insulation Tape for Ductwork, Ducting, Sealing, Patching, Furnace

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ETERART Aluminum Foil Duct Tape, High-Temp Seal for HVAC,2" x 20Yds | Heavy-Duty, Dryer Vents & Insulation, Stops Air Leaks & Resists Extreme Heat for Home Repair, Silver, easy to apply, durable

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Pipe insulation sizing

Sleeves are sold by pipe inside diameter (1/2 inch and 3/4 inch cover most homes) and by wall thickness (3/8 inch for mild spaces, 1/2 to 1 inch for unheated crawls and attics). Buy self-sealing slit foam and tape every joint and elbow.

Insulate the first 6 feet of hot and cold lines at the water heater at minimum; the whole hot run if it passes through unconditioned space.

Water heater blankets

An R-8 to R-11 blanket cuts standby loss 25–45% on an older tank and typically pays back in under a year. Modern tanks with factory R-16+ insulation gain much less — check the label before buying.

Gear for this job

Frost King SP57/11C All Season Water Heater Insulation Blanket, 3” Thick x 48” x 75”, R10

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AES Industries Water Heater Blanket Jacket Insulation Non Fiberglass Fits 40 50 60 and 80 Gallon Tank R8

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76"x48" Water Heater Insulation Blanket for 40-80 Gallon Pre-Oxidized Fiber | Soft tight fit, easy cut & install, includes 25.5" round top spacer & 16FT foil tape for complete installation

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Frost King SP60 All Season Water Heater Insulation Blanket, 3” Thick x 60” x 90”, R10

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Gas heater safety

Never cover the top of a gas water heater, the flue, the burner access panel, the thermostat, the pressure relief valve or the drain. Leave the bottom 6 inches clear so combustion air can reach the burner. Electric tanks can be wrapped fully except the controls and label.

Freeze protection

In hard-freeze climates, pipes on exterior walls or in unheated crawls should get insulation plus, where risk is real, self-regulating heat cable installed under the insulation per the manufacturer's directions.

Run the numbers

Pipe Insulation Calculator Water Heater Blanket Calculator Duct Insulation Calculator

Frequently asked questions

Does a water heater blanket save money?: On older tanks yes — typically $20–$60 a year, paying back in under 12 months. Newer high-efficiency tanks gain little.
What thickness of pipe insulation do I need?: 3/8 inch wall in conditioned spaces, 1/2 to 1 inch in unheated crawl spaces, attics and garages.
Can I insulate a gas water heater?: Yes, but keep the top, flue, burner access, thermostat and relief valve completely clear.

Insulation gear worth owning

The tools and materials that show up on almost every insulation job.

Duck Brand Foam Pipe Covers, Pipe Insulation Foam Tubes for Hot and Cold Water Pipes, Pre Slit and Self Sealing Adhesive Edge, 0.75 in. x 1 Ft., 6 Sticks Per Package, 6 Feet Total, Black

Check price on Amazon

Frost King SP57/11C All Season Water Heater Insulation Blanket, 3” Thick x 48” x 75”, R10

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Romeda Aluminum Foil Tape, 2 inch x 65 Feet Foil Tape (3.9 mil), Silver Insulation Adhesive Metal Tape, High Temperature Heavy Duty HVAC Tapes for Ductwork, Dryer Vent, HVAC

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Frost King CF55 Foil Backed "No Itch" Natural Cotton Duct Wrap, 12-Inch x 1-Inch x 15-Feet

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