Authorized Sub Zero Covers Dealer
We're an authorized dealer for Sub Zero Covers freeze bags — premium, USA-made insulation blankets built to a higher standard than thin imported covers. Standard sizes stocked, custom sizes to order.
Authorized Sub Zero Covers Dealer • Made in the USA
Backflow Freeze Bags & Insulation Blankets
Protect your backflow preventer from freeze damage with heavy-duty insulated freeze bags from Sub Zero Covers, made in the USA. Over 50 standard sizes from XS to XXXXL, plus custom sizes to order — because one size never fits all.
50+ Sizes In StockMade in the USAFast Nationwide Shipping
Why Choose Our Backflow Freeze Bags
As an authorized Sub Zero Covers dealer, we bring you premium, USA-made freeze protection built to a higher standard — with standard and custom sizes for virtually any assembly.
Heavy-Duty Freeze Protection
Our backflow insulation blankets use high-density insulation with UV-resistant outer shells to protect your backflow preventer from freezing temperatures season after season.
50+ Sizes Available
From compact 3/4-inch residential devices to massive 10-inch industrial assemblies, we stock over 50 freeze bag variants so you always get the right fit.
Made in the USA
Proudly made in the USA. Sub Zero Covers freeze bags support American manufacturing and meet quality standards that imported products simply cannot match.
Fast Shipping & Local Pickup
Order online and get fast shipping nationwide, or pick up locally from our Rocklin, CA warehouse. We keep all sizes in stock and ready to ship.
Easy Installation
No tools required. Our backflow freeze bags slip on in under two minutes with secure strap closures. Quick to install, quick to remove for testing season.
Freeze Bag Sizes — XS to XXXXL
Use the size guide below to find what fits your device, then head to our store to order.
Shop All Sizes on Our StoreXS
Fits 3/4" devices
Small compact assemblies
S
Fits 3/4" - 1" devices
Standard residential
M
Fits 1" - 1-1/2" devices
Larger residential assemblies
L
Fits 1-1/2" - 2" devices
Small commercial assemblies
XL
Fits 2" - 2-1/2" devices
Standard commercial assemblies
XXL
Fits 3" - 4" devices
Large commercial assemblies
XXXL
Fits 4" - 6" devices
Industrial assemblies
XXXXL
Fits 6" - 10" devices
Large industrial assemblies
Shop All Sizes on Our Store
Don't see your size? Contact us for a custom quote.
Premium Freeze Bags, Made in the USA
Unlike suppliers who push thin imported covers, The Backflow Depot is an authorized dealer for Sub Zero Covers — premium backflow freeze protection bags made in the USA. Each insulation blanket is built to the quality and consistency that your backflow preventer deserves.
Sub Zero Covers was born out of frustration with the poor quality coming from overseas — thin insulation, weak stitching, and one-size-fits-none designs. Their bags are a better product, and with over 50 size variants they fit virtually any backflow assembly on the market.
When you buy a freeze bag from The Backflow Depot, you get Sub Zero Covers quality paired with our sizing expertise and fast shipping — standard sizes in stock and custom sizes available to order.
How to Size Your Backflow Freeze Bag
Getting the right fit is critical for proper freeze protection. Use our free sizing tool — it takes 30 seconds.
Snap a Photo. Get Matched Instantly.
Take a picture of the metal tag on your backflow device. Our tool reads the manufacturer, model, and size — then sends you straight to the right freeze bag, ready to buy.
Get The Right Freeze Bag SizeFree. No account needed. Works on any phone.
Or size it manually
1
Measure Your Device
Measure the overall length, width, and height of your backflow preventer assembly, including valves, test cocks, and any protruding fittings.
2
Check the Pipe Size
Note the pipe diameter of your backflow preventer (e.g., 3/4", 1", 2", 4"). This is the primary factor in selecting the correct freeze bag size.
3
Match to Our Size Chart
Compare your measurements to our size grid below. If you fall between two sizes, choose the next size up to ensure full coverage and proper insulation.
4
Need Help? Call Us
Not sure which size fits? Use our freeze bag sizing tool at app.thebackflowdepot.com or call 916-251-7071. We will size it for you for free.
Frequently Asked Questions About Backflow Freeze Bags
Everything you need to know about backflow freeze protection, sizing, installation, and ordering.
How do I choose the right freeze bag size for my backflow preventer?
Measure the overall length, width, and height of your backflow preventer assembly including any valves and test cocks. Match those measurements to our size chart, which ranges from XS (for compact 3/4-inch devices) up to XXXXL (for large 10-inch assemblies). If you are between sizes, choose the next size up for a proper fit. You can also call us at 916-251-7071 and we will help you find the right size.
Will your freeze bags fit any brand of backflow preventer?
Yes. Our backflow freeze bags are designed to fit all major backflow preventer brands including Watts, Wilkins/Zurn, Febco, Ames, and Apollo. With over 50 size variants, we have a freeze bag for virtually every residential, commercial, and industrial backflow device on the market.
How do I install a backflow freeze bag?
Installation is simple and requires no tools. Slip the insulated freeze bag over your backflow preventer assembly, secure the built-in straps or drawstring closure around the piping, and make sure all exposed components are covered. The entire process takes about two minutes. Remove the bag when temperatures rise to allow access for testing.
How long do your backflow freeze bags last?
Our freeze bags are built to last multiple seasons. They are built with heavy-duty, UV-resistant outer shells and high-density insulation that maintains its R-value year after year. With proper storage during warm months, most customers get 5 to 10 years of reliable freeze protection from a single bag.
Do you offer custom-sized freeze bags for unusual backflow installations?
Absolutely. Sub Zero Covers produces custom-sized insulation blankets for non-standard backflow preventer installations, and as an authorized dealer we can order them for you. Contact us through our website or call 916-251-7071 to discuss your custom freeze bag needs.
Protect Your Backflow Preventer Before the Next Freeze
Do not wait until temperatures drop. Order your Sub Zero Covers backflow freeze bag today — 50+ sizes in stock, made in the USA, and ready to ship.