If you live in the Northeastern U.S., you already know winter can be unpredictable. Losing power is inconvenient enough—but discovering your hot tub has frozen solid is a nightmare no homeowner wants. A hot tub is a major investment, and the last thing you need is a backyard ice sculpture where your spa used to be.
The good news: don’t panic.
Most modern hot tubs can withstand several days without power, even in sub‑zero temperatures. With the right steps, you can dramatically reduce the risk of freeze damage during a prolonged outage.
This guide walks you through exactly what to do—before, during, and after the power goes out.
Keep the Heat In
Leave the Cover On
Think of your hot tub like a refrigerator—but in reverse. During a power outage, your goal is to keep the heat trapped inside for as long as possible.
A well‑sealed cover is your first line of defense against rapid heat loss.
Slow Down Temperature Loss Before the Storm
If you know severe weather is coming, you can buy yourself valuable time.
Turn Up the Temperature
Set your hot tub to its maximum temperature. Some models even offer an extended‑temperature mode above the standard 104°F—check your manual to see if yours does.
A wireless thermometer is a great tool for monitoring water temperature without lifting the cover.
Add a Thermal Blanket
A floating thermal blanket (similar to a pool solar cover) adds an extra layer of insulation.
They’re easy to trim to size and can significantly reduce heat loss.
What to Do When the Power Goes Out
Do NOT Drain Your Hot Tub
This is one of the biggest mistakes homeowners make.
Draining the tub exposes plumbing lines and equipment to freezing air. Unless you can fully evacuate every drop of water with a shop vac—and power to run it—you risk catastrophic freeze damage.
Insulate the Equipment Compartment
Even the best‑insulated hot tubs have a weak point: the equipment bay.
Normally, this area vents heat to prevent the pump from overheating. During an outage, that venting works against you.
To protect it:
Turning off the breaker is essential—you don’t want the hot tub powering back on unexpectedly and overheating the insulated equipment.
Add Hot Water (If the Outage Will Last Days)
If you expect to be without power for 3–5 days:
Avoid splashing hot water onto the exposed shell—it may be cold and could crack.
Use Non‑Toxic Antifreeze (Last Resort)
You can add non‑toxic RV or pool antifreeze—about 10% of your water volume—and mix manually.
This method works, but once power returns, you’ll need to fully drain and refill the tub.
If You Have a Generator
A generator can be a game‑changer, but only if your hot tub is wired for it.
Powering the Hot Tub
Some hot tubs have two breakers:
If your hot tub is wired this way, a qualified electrician can connect the heater circuit to your generator. For most homeowners, a whole‑house generator is the safest and most reliable option.
Direct Heat Options
If you can’t power the hot tub itself, you can still warm the equipment compartment:
Both provide gentle heat to prevent freezing.
Keep Water Moving
A submersible pump placed at the bottom of the tub and run continuously helps delay freezing. Moving water freezes much more slowly, and the pump generates a small amount of heat through friction.
Bucket Heater
A bucket heater placed inside a bucket (to prevent shell contact) can add supplemental heat to the water.
Last‑Minute Option: Winterize the Hot Tub
If you have enough warning before a major storm, you can fully winterize your hot tub.
This is the most labor‑intensive option and should only be attempted if you’re confident in the process—otherwise, call a professional.
Safety First
Use caution and common sense with any of these strategies.
If you’re unsure how to proceed, it’s always better to consult a professional than risk damaging your spa.
Next Steps: Protect Your Investment
Preparing your hot tub for winter power outages is one of the smartest ways to protect your investment. A few proactive steps can prevent thousands of dollars in freeze damage and keep your spa ready for year‑round enjoyment.
By planning ahead, you ensure:
Stay informed, stay prepared, and give your hot tub the care it deserves—even when the power goes out.