How Long Does a Lazy Spa Take To Heat Up?

Written By: Jen

Last Updated:

This post may contain affiliate links. If you click one, I may earn a commission at no cost to you. As an Amazon Associate, I earn from qualifying purchases.

You’ve finally filled up your Lay-Z-spa and you’re ready to enjoy a relaxing hot tub after a long hard day. You dip the tip of your finger into the water to find it freezing cold.

That’s supposed to be a hot tub, not a cold tub! Especially not a freezing cold tub. How long is this thing going to take to heat up?

lazy spa hot tub

That’s what we’ll be discussing In this article, how long does a lazy spa take to heat up. Additionally, is there something you can do to speed that process up? And is there something you shouldn’t do when heating the tub?

How Long Does a Lazy Spa Take To Heat Up

Lay-Z-Spa heater pump heats the water by approximately 34.7 °F an hour. This means heating time can vary between different tubs and can take anywhere from 24 up to 48 hours to heat up, maybe longer. It’s a pretty big range.

Why such a big range? Well, there are some factors that could add to your tub’s heating time.

The biggest one is, What’s the temperature coming out of your garden hose? Additionally, the capacity of the tub and the ambient air temperature can significantly increase your Lay-Z-spa heating time.

As a hot tub owner, there are some reasons why you need to reheat a hot tub:

  • Filling a freshly bought Lay-Z-spa
  • Refilling it after draining
  • Lowering the water temperature between uses, which requires reheating
  • Shutting down the heater during winter
heating up a lazy spa

Factors That Affect Lay-Z-Spa Heating Time

Let’s look at how the air temperature, water temperature, and tub size can increase your Lay-Z-spa heating time.

1. Water Temperature

Almost all of us fill up our hot tubs from our garden hose. The average garden hose water temperature can range from 60 to 75 °F and sometimes below that, depending on where you live.

The water temperature sitting in your Lay-Z-spa can affect how long it takes to heat up. Water temperature can be around 80 °F on a warm day, Which will decrease the water heating time. 

However, it’s only about 2 to three hours difference, which wouldn’t matter if you’d wait about 18 hours for a big tub.

On a cold day, the water temperature will be anything from 55 to 70 °F, which will add a couple of hours to your waiting time.

a woman lying on the side of an inflatable hot-tub

2. Air Temperature

The air surrounding your hot tub is one of the main reasons the water would heat up for a long time. That’s because heat will transfer from the hot water to the relatively cooler air, which is why a tub lid is always recommended.

Think of it as when you leave a hot cup of coffee to cool down naturally. Air will act as a heat suction, which pulls the heat out of the hot coffee.

3. Tub Size

Bigger size tubs mean larger amounts of water, and smaller size tubs mean less water. Having more water to heat up can dramatically increase your spa waiting time. Surprisingly, Lay-Z-spa has a huge range of tubs.

man relaxing on the inflatable hot-tub

The Lay-Z-Spa Range

Let’s look at some of Lay-Z-spa’s tub sizes and understand how their size will affect the heating time.



Check Latest Price

Miami Airjet belongs to the smallest sizes category in the Lay-Z-spa hot tubs range. Its capacity is 2-4 adults and the water capacity is about 177 Gallons.

Heating up the Miami Airjet can take an average of 6 to 12 hours to heat the water.


Singapore AirJet Plus Inflatable Spa
Check Latest Price

Singapore Airjet is one of Lay-Z-spa’s bigger tubs, which has a capacity of 3-5 adults and the water capacity is about 213 Gallons.

Heating up the Singapore tub can take anything between 10 to 16 hours, with a maximum heat capability of 104 °F


Check Latest Price

Their next category is 4-6 adults, with a water capacity of 240 Gallons. The Hollywood Airjet takes about 14 to 20 hours to heat up the water.


Check Latest Price

Helsinki Airjet is a 5-7 seater tub. And a maximum water capacity of 297 Gallons. Heating up this big tub requires approximately 19 to 25 hours to reach its operating temperature (104 °F).


Check Latest Price

Finally, for their biggest size tub, Grenada Airjet can comfortably seat 6-8 adults. With a water capacity of a whopping 357 Gallons. No wonder why it would take anything from 24 to 36 hours for this tub to heat up.

How to Heat Lay-Z-Spa Faster

There are some tips you can use to heat your Lay-Z-spa faster, and the great thing about them is they’re tested and proven to succeed.

1. Close the Lid

Without the lid, the water in your tank is exposed to the outside cold air. This will make it difficult for the heater pump to heat up the water. The lower air temperature will be working against the higher water temperature causing it to consecutively lose heat.

Think of it as if you’re boiling water in a large pot. Without the lid, it feels like it would take forever to boil. Once you throw a lid on top, the water starts boiling in almost half the time it needs without the lid.

lazy spa hot tub lid

2. Use a Floating Thermal Blanket

If you’re not familiar with thermal blankets, they’re specially-engineered blankets that do an incredible job of retaining heat. If you place one on top of your tub, they’ll float over the water and retain heat, much like a lid.

Keep your hot tub water warm

Won’t be damaged by water or sunlight

Reduces water evaporation by 90%

Check Latest Price

3. Turn You Tub’s Water Features and Jets On

Turning the water jets on will tremble the water’s surface, which will improve water circulation and heat transfer. Once the water reaches the jet’s operating level, turn them on for a faster Lay-Z-spa heat up.

4. Buy a Bigger Heater

Big tubs require stronger water heater pumps, while small tubs are good with a smaller heater pump. However, that doesn’t mean you can’t buy a bigger heater pump for your 4-seater tub. 

Luckily, Lay-Z-spa offers three types of heater pumps. So, if you’re okay with spending some extra bucks for a quicker heat up. Lay-Z-spa has got you covered.

What Not to Do to Your Lay-Z-Spa

One thing you should never do when heating up your tub is to add boiling water from your stove. Unless you have a 100-gallon pot, which no one does!

It’ll take forever to make serious changes to your tub’s water temperature.

Additionally, putting boiling water in the tub can seriously damage your tub’s shell, plumbing, and inner equipment. This is because hot tubs, especially Lay-Z-spa, are designed for a maximum of 104 °F. Anything more than that will leave you with a broken hot tub.

never add boiling water to your lazy spa

The Bottom Line

Lay-Z-spa has a wide range of tub sizes, which require serious hours to heat up. Depending on the size, water temperature, and air temperature, your tub can take anywhere from 6 to 12 to 24 and sometimes 48 hours to completely heat up.

You can speed up this process by covering the tub with its lid. If the lid is not an option, a tarp or thermal blankets will do the job. You can also switch to a bigger water heater and turn on the jets on your tub to decrease your waiting time.

Now you know how long a lazy spa takes to heat up, you’ll never miss your relaxing schedule after working your fingers to the bone.

Photo of author


Jen is your go-to expert on all things inflatable, from pools to tents and beyond. A former hot tub rental company owner, she's experienced the ups and downs of inflatables firsthand. Nowadays, she writes practical guides on maintaining and enjoying inflatables. A mom of young enthusiasts, her family's favorite outing is the inflatable fun park!

Leave a Comment