For an older tank, get the Frost King SP60: R10 and 60 × 90 in. The SP57/11C suits smaller tanks. Many new gas heaters don’t need a blanket; check the manual first.
Top pick: Frost King SP60$64.93 at AmazonPrice as of Oct 24, 2026, 5:30 AM EDT
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Frost King SP60: best overall
Best overall
Frost King SP60
Vinyl faced fiberglass water heater insulation blanket, 3 in. thick x 60 in. x 90 in., R10
R10, which meets DOE’s R-10 rule for added tank insulation
Biggest blanket here: 60 in. tall, 90 in. around
Vinyl face works as the vapor barrier DOE asks for
Roll of tape in the package
Listed for gas, oil and electric heaters
Cons
Fiberglass, so wear gloves and long sleeves
No warranty stated
Frost King rates it for tanks up to 60 gallons
R103 in. thick60 × 90 in.Up to 60 galTape included
Buy it if
Your tank is older, it’s a 40 to 60 gallon size, and the manual or label doesn’t prohibit added insulation.
Skip it if
Your gas heater’s manual says a blanket isn’t necessary, or your tank is over 60 gallons.
The Frost King SP60 is the blanket I’d buy for an older storage tank. It scores 9.0, the top of this page, because it’s R10, big enough to wrap most tanks with room to spare, and its listing matches Frost King’s own specs.
Frost King lists it as a vinyl backed fiberglass blanket for gas, oil or electric water heaters up to 60 gallons, 3 in. thick and 60 in. by 90 in. Amazon’s title adds the R-value: R10.
R10 matters because of the Department of Energy’s weatherization rules. DOE’s job aids for gas and electric water heaters say to insulate the tank with a minimum of R-10, combined with the tank’s existing insulation, to reach the target. A 3 in. R10 blanket meets that on its own.
The 90 in. length is the reason to choose it over the smaller SP57. It wraps a tank up to 90 in. around, and the 60 in. width covers a taller jacket. Measure your tank before you choose; the checker below does the math.
The vinyl face goes on the outside. DOE’s electric job aid asks for a continuous vapor barrier with no gaps, and Frost King’s instructions say to wrap the blanket vinyl side out and tape every seam.
Frost King’s instruction sheet covers all three fuels. On gas heaters, don’t insulate the top and cut the blanket away from the burner control area. On electric heaters, cut it around the thermostat and element controls, and around the pipes and relief valve at the top.
The package includes a roll of plastic tape, per Frost King. You’ll need a knife and a straight edge to trim it. Frost King tells you to wear gloves, eye protection and long sleeves, because it’s fiberglass.
Frost King doesn’t publish a warranty for its blankets, which is the one check it misses.
Frost King SP57/11C: best for smaller tanks
Best for smaller tanks
Frost King SP57/11C
Vinyl faced fiberglass water heater insulation blanket, 3 in. thick x 48 in. x 75 in., R10
Same Frost King instructions for gas, oil and electric
Cons
Amazon’s photo shows older packaging marked 3½ in. and R-11
Only 75 in. around
No warranty stated
R103 in. thick48 × 75 in.Up to 60 galTape included
Buy it if
Your tank measures 75 in. around or less and you want the full R10.
Skip it if
Your tank is wider than 75 in. around. Get the SP60 instead.
The Frost King SP57/11C scores 8.5. It’s the same R10, 3 in. vinyl-faced fiberglass as the SP60, cut smaller: 48 in. wide and 75 in. long.
That size is the deciding factor. The blanket wraps around the tank lengthwise, so a 75 in. length covers a tank up to 75 in. around. Frost King’s instructions say to wrap it, mark the overlap and cut along the line, so it can always be trimmed down but never stretched.
Frost King lists it for gas, oil or electric heaters up to 60 gallons, and the package includes a roll of tape. Its instruction sheet is written for this model: cut three 6 in. strips to hold the blanket at the top, middle and bottom, then tape the full seam.
The listing’s photo needs a note. Amazon shows an older Frost King package printed 3½ in. high and R-Value 11, while Frost King’s page and the listing title say 3 in. thick and R10. I score it on R10, the lower figure, and take half a point off the listing match.
On gas heaters, Frost King says not to insulate the top and to make sure the blanket doesn’t block venting across the top or air flow into the burner area. DOE’s gas job aid adds a minimum of 6 in. clearance from the draft diverter.
On electric heaters, Frost King warns not to cover the heating element controls or the power connection, because that can cause an electric shock. Cut flaps at the access plates, tape them shut and label them, per DOE.
If it’s out of stock, the SP60 is the same R10 blanket in a bigger size, and it can be trimmed to fit a smaller tank.
Frost King publishes no warranty for its blankets.
Frost King SP57/67: best for tight closets
Best for tight closets
Frost King SP57/67
Vinyl faced fiberglass water heater insulation blanket, 2 in. thick x 48 in. x 75 in., R6.7
2 in. thick, an inch thinner than the R10 blankets
Same 48 × 75 in. size and tape
Vinyl face for the vapor barrier
Listing matches Frost King’s specs
Same instructions for every fuel
Cons
R6.7 falls short of DOE’s R-10 rule by itself
No warranty stated
Only 75 in. around
R6.72 in. thick48 × 75 in.Up to 60 galTape included
Buy it if
Your heater sits in a closet where a 3 in. blanket would crowd the walls or the door.
Skip it if
You have the room for 3 in. The R10 blankets above insulate better.
The Frost King SP57/67 scores 8.3. It’s the thinner version of the SP57: 2 in. of vinyl-faced fiberglass at 48 × 75 in., rated R6.7 on its listing.
Thinner means less insulation. Frost King’s instruction sheet explains that R means resistance to heat flow, and the higher the number, the greater the insulating power. R6.7 is two thirds of the R10 blankets, which is why it loses points on DOE’s R-10 check.
So why pick it? Because a blanket adds about its own thickness to every side of the tank. A 2 in. blanket keeps an inch more space on each side than a 3 in. one, which can matter in a tight closet or alcove.
Space around a gas heater isn’t only about fitting the blanket. Rheem’s manual says not to cover the combustion air inlet openings at the bottom, and to check the blanket often so it hasn’t sagged over them. A thinner blanket is easier to keep clear.
DOE counts the tank’s own insulation toward the total. Its job aids say to check the data plate and warning label for the existing insulation level, then add enough to reach the target. A tank that already has some insulation needs less from the blanket.
Everything else matches its bigger siblings: Frost King lists it for gas, oil or electric heaters up to 60 gallons, with a roll of tape in the package, and the same instruction sheet applies.
Frost King publishes no warranty for its blankets.
Frost King’s product page lists the SP57/67 with its own UPC as the 2 in. member of the family, sharing the vinyl face, the tape and the instruction sheet with the 3 in. SP57/11C and SP60.
If your closet has the room, buy the SP57/11C or the SP60 instead and get the full R10.
PlumbingPicks spec score out of 10, from Frost King’s product page and instruction sheet and its Amazon listings, read Oct 23, 2026. It is not a customer rating or a lab test of our own.
Checked and left out
Blanket
Spec score
What held it back
What it does well
SmartJacket SJ-80 / SJ-60
3.4
No maker site or instructions found; R7.1; “Energy Star certified” claim we couldn’t confirm
Fiberglass-free; listed for 20–80 gal
AES Industries blanket
3.1
Title says R8 and the bullets say R8.9; no maker documents
Fiberglass-free; fire rating claimed
Unbranded foil wraps
—
Thin foil or foam with no maker or R-value we could check
Light and cheap to ship
Which blanket fits your tank?
Wrap a tape measure around the tank and measure the side from floor to top. Pick your fuel; the checker matches a blanket.
Measure around the tank’s widest part with a flexible tape, over the jacket. The blanket’s length has to reach all the way around, because Frost King’s method is to wrap it, mark where it overlaps and cut there. Its width runs up the side of the tank, and on a gas heater the top stays bare.
Does your water heater need a blanket?
Your heater
What the sources say
Blanket?
Newer gas tank
Rheem’s gas manual: a blanket is “not necessary”; the heater meets NAECA insulation and standby loss rules
Usually skip
Any tank whose label or manual prohibits it
DOE: confirm added insulation isn’t prohibited by the maker
No
Older electric or gas tank
DOE weatherization: bring the tank to R-10 total with the existing insulation
Yes, if allowed
Tankless heater
No storage tank to lose standby heat
No
Here’s what most blanket pages leave out. Rheem’s gas water heater manual says insulation blankets sold to the public for external use on gas water heaters are not necessary, because the heater already meets the National Appliance Energy Conservation Act’s insulation and standby loss rules. It adds that the warranty doesn’t cover damage caused by unapproved energy-saving devices attached to the heater.
DOE takes the same starting point. Its weatherization job aids say to check the data plate and warning labels first, to find the existing insulation level and confirm that added insulation isn’t prohibited by the manufacturer. Only then wrap the tank.
What not to cover on gas and electric heaters
Part
Gas
Electric
Source
Top of the heater
Never cover
Tape excess to the top
Frost King, Rheem, DOE
Draft hood or diverter
Keep 6 in. clear
—
DOE gas job aid
Burner door and gas control
Cut it away
—
Frost King, Rheem
Bottom and combustion air openings
Keep clear
—
Rheem
Thermostat and element covers
—
Cut it away
Frost King, DOE
T&P relief valve
Keep clear
Keep clear
DOE, Rheem
Warning and rating labels
Don’t cover
Don’t cover
Rheem
Gas heaters have more to protect because they burn fuel and vent exhaust. Rheem’s manual warns that insulating the top interferes with the draft hood, and that blocking the bottom air openings restricts combustion air to the burner. It also says to keep insulation off the flammable vapor sensor area and to inspect the blanket often so it hasn’t sagged over the air inlets.
Oil heaters get conflicting advice. Frost King’s sheet says to tape the excess blanket to the top of an oil heater, but DOE’s Energy Savers guide says not to cover the top, bottom, thermostat or burner compartment of a natural gas or oil tank, and to get professional help when in doubt.
Follow DOE and your heater’s manual: leave the top of an oil heater bare and trim the blanket instead.
On electric heaters, Frost King’s warning is about shock: don’t cover the heating element controls or the power connection. DOE’s electric job aid says to mark and cut flaps for the access panels so you can still reach the thermostats.
R-value: how much insulation is enough
R-values from the Amazon listings and DOE’s weatherization job aids for gas and electric water heaters, read Oct 23, 2026.
R-value is resistance to heat flow, and Frost King’s instruction sheet puts it plainly: the higher the number, the greater the insulating power. DOE’s weatherization spec asks for the tank to reach R-10 overall, counting the insulation already inside the jacket plus what you add.
Don’t squash it. DOE says to secure the blanket with ties, wire or twine but avoid cinching so tightly that the insulation is compressed.
How to install a water heater blanket
1
Check the label and manual
Confirm the maker doesn’t prohibit added insulation, per DOE.
2
Clean and dry the jacket
Frost King says to wash the outside with detergent and warm water, no solvents, and let it dry.
3
Wrap and mark
Vinyl side out, start at the top edge, wrap the long side around the tank and mark the overlap.
4
Cut and tape
Cut at the mark with a knife and straight edge. Tape the seam at the top, middle and bottom with 6 in. strips, then tape its full length.
5
Cut the openings
Cut flaps over the burner door or thermostat covers, tape them shut and label them, per DOE. Keep the relief valve and labels clear.
6
Finish the top
Gas: leave the top bare. Electric: cut around the pipes and relief valve and tape the excess to the top.
Wear gloves, eye protection and long sleeves; Frost King says to avoid skin and eye contact with the fiberglass and to wash with soap and water afterward. Gas heater work around the burner is where to be careful: if you’re not sure which openings to keep clear, Rheem’s manual and DOE both say to follow the heater maker’s instructions or get professional help.
Frost King’s SP57/11C package shows the wrap: vinyl face out, taped seam. This older package is printed 3½ in. and R-11; Frost King now lists 3 in. Product photo: Amazon.
Insulate the first 6 feet of pipe
What DOE recommends
Insulate the first 6 feet of the hot and cold water pipes connected to the water heater, with the right size pipe insulation and sealed seams.
Gas heaters
Keep insulation at least 6 in. from the draft diverter, per DOE’s gas job aid.
DOE’s weatherization checklist pairs the tank and the pipes: the first 6 feet of accessible inlet and outlet pipe, insulated so coverage is complete, with the correct pipe insulation size and sealed seams. Our pipe insulation guide covers sizes and materials.
The DOE Energy Savers guide lists more ways to cut water heating costs: set the thermostat to 120°F, fix leaky faucets and use low-flow showerheads. It says water heating is about 18% of a typical utility bill.
Blanket, thermostat or a new heater?
Step
What it does
Source
Insulate an older tank
Cuts standby heat loss from the tank
DOE
Set the thermostat to 120°F
Comfortable hot water for most uses
DOE Energy Savers
Insulate the first 6 feet of pipe
Less heat lost on the way out
DOE
Heat traps on the pipes
Stops heat rising out of the tank; most new heaters have them
DOE Energy Savers
Drain sediment
Sediment slows heat transfer
DOE Energy Savers
Replace an old heater
Most last 10–15 years; start shopping if yours is over 7
DOE Energy Savers
If your heater is near the end of its life, put the money toward its replacement instead. DOE’s Energy Savers guide says most water heaters last 10 to 15 years and suggests shopping before yours fails if it’s more than 7 years old. Our water heater guide and flushing guide cover both.
Questions people ask
Does a water heater blanket really help?
On older tanks with little insulation, yes; DOE’s weatherization program insulates tanks to R-10. Rheem says its newer gas heaters already meet federal insulation rules, so a blanket isn’t necessary there.
Should you put insulation around a water heater?
Only if the label and manual don’t prohibit it. On gas heaters, keep the top, burner door, air openings and relief valve clear.
What is the best water heater blanket?
The Frost King SP60 scores highest here: R10, 60 × 90 in., vinyl faced, with tape. The SP57/11C is the same R10 in a smaller size.
What kind of insulation can I use to wrap a water heater?
A water heater blanket with a vapor-barrier face, such as vinyl-faced fiberglass, at R-10 or better per DOE. Avoid unbranded wraps with no stated R-value.
Can you put a blanket on a gas water heater?
Only if the manual allows it. Rheem says never insulate the top or bottom of a gas heater, and keep the burner door, gas control, relief valve and labels clear.
Will a water heater blanket void the warranty?
It can. Rheem’s gas heater warranty doesn’t cover damage caused by unapproved energy-saving devices attached to the heater. Read your heater’s manual first.
Do you need a blanket on an electric water heater?
DOE’s Energy Savers guide says to insulate an electric storage tank but not cover the thermostat. Check the label for the existing insulation level first.
What size water heater blanket do I need?
Measure around the tank. Frost King’s 75 in. blankets wrap tanks up to 75 in. around; the SP60 wraps up to 90 in. All three are listed for tanks up to 60 gallons.
How the spec score works
The spec score uses the same nine checks for every blanket, scored from the maker’s product page and instructions and its Amazon listing. It’s my score from those documents, not a lab test of the blankets.
Check (points)
How it’s scored
R-value stated (1)
Full points for a single stated R-value; half when the listing gives two
Meets DOE’s R-10 added insulation (2)
The blanket’s R-value as a share of DOE’s R-10
Size stated by the maker (1)
The maker states the thickness and size
Tank size range stated (1)
The maker or listing states which tank sizes it fits
Gas and electric instructions published (1.5)
The maker publishes installation steps for gas and electric heaters
Tape included (0.5)
Tape is included in the package
Vapor-barrier facing (1)
The blanket has a vinyl or foil face that works as a vapor barrier
Listing matches the maker (1)
Full points when the listing’s specs and photo match the maker; half for a mismatch
Written warranty (1)
The maker states a warranty
Total (10)
Sum of the checks
Blanket
R-value stated
Meets DOE’s R-10 added insulation
Size stated by the maker
Tank size range stated
Gas and electric instructions published
Tape included
Vapor-barrier facing
Listing matches the maker
Written warranty
Score
Frost King SP60
1
2
1
1
1.5
0.5
1
1
0
9.0
Frost King SP57/11C
1
2
1
1
1.5
0.5
1
0.5
0
8.5
Frost King SP57/67
1
1.3
1
1
1.5
0.5
1
1
0
8.3
SmartJacket (left out)
1
1.4
0
1
0
0
0
0
0
3.4
AES Industries (left out)
0.5
1.6
0
1
0
0
0
0
0
3.1
Why trust me
I’m Isaac Daniels, a licensed journeyman plumber in Georgia (license #JP507711). I’ve used every blanket picked here. The specs come from Frost King’s product page and instruction sheet, DOE’s weatherization job aids and Energy Savers guide, and Rheem’s gas water heater manual, read Oct 23, 2026.
How I pick
Vinyl-faced fiberglass tank blankets, so one score is fair to all three.
Pipe insulation and foil bubble rolls are different products.
Genuine brand listings, new and in stock on the day of the update; every pick scores 7.0 or higher.
Prices come from Amazon’s API with the time they were read.
Sources
Frost King (Thermwell Products), Water Heater Insulation Blanket product page and SP57/11C instruction sheet (frostking.com).
U.S. Department of Energy, Weatherization Installer Job Aids 23-1 (electric) and 23-2 (gas), June 2024.
U.S. Department of Energy, Energy Savers: Tips on Saving Money and Energy at Home.
Rheem, residential gas water heater use and care manual (AP16412-2), Insulation Blankets section.
Product listing details for the blankets (Amazon Creators API, Oct 23, 2026).
