Can You Fill a Hot Tub With Hot Water?

In a bid to reduce the cost of heating your hot tub, you might ask yourself, can you fill a hot tub with hot water? Here is the answer to that.

You shouldn’t fill a hot tub with hot water to prevent damages to the hot tub. Hot tubs by design are to be used with a maximum water temperature of 104 degrees Fahrenheit. Most water heaters can get the water as hot as 140 degrees Fahrenheit. So when you add hot water into your hot tub, you are adding water that is too hot for the hot tub to handle and this can damage the hot tub’s components.

This post reveals all you need to know about filling your hot tub including the best water to put in a hot tub. Let’s dive in.

Everyone wants to save money, some people think that filling up a hot tub with hot water will help them save money. So can you fill a hot tub with hot water? No, you can't. Usually, hot water is too hot for the hot tub and it can damage it.

Is It Cheaper To Fill A Hot Tub With Hot Water?

It is cheaper to fill a hot tub with hot water. Filling a hot tub with hot water will cost you less than filling the hot tub with cold water and then heating it to 100 degrees Fahrenheit.

Hot tubs contain a lot of water. Even the smaller 2-3 person hot tub can contain over 300 gallons of water. Not to mention the larger 6-8 person hot tubs that contain over 600 gallons of water. Heating this amount of water to 100 degrees Fahrenheit will take hours and will raise the electricity bill.

A cheaper alternative is to fill the hot tub with hot water so you don’t have to use as much electricity to heat the water. But while this may seem like a cheaper alternative, it is not the best for your hot tub because filling a hot tub with water that has a temperature over 104 degrees Fahrenheit will damage the hot tub components.

Also, filling your hot tub with hot water is a very hectic and time-consuming process. Regardless of the size of the pot that you use, you will have to heat water multiple times to fill up the smallest hot tubs. Not to mention the larger models.

So while it may seem like a cheaper alternative, there are a lot of risks associated with filling your hot tub with hot water. Let’s check out some of these risks below.

Related Read: Can You Use a Hot Tub With Cold Water?

Can Hot Water Damage A Hot Tub?

Yes, filling your hot tub with hot water can damage the shell and delicate parts of the hot tub like the filter material.

Filling your hot tub with hot water might seem safe since hot tubs are used with hot water. But it’s not. Hot tubs are designed for a maximum water temperature of 104 degrees Fahrenheit. Most household heaters on the other hand can heat water up to 140 degrees Fahrenheit. This water temperature is too hot for hot tubs to handle.

So when you fill your hot tub with hot water from the heater in your kitchen, you are exposing the hot tub’s components to water temperature that is about 36 degrees hotter than what they are designed to handle. This will damage several components of your hot tub especially the shell.

The shell will begin to crack till there is a large tear in the walls of your hot tub. The delicate parts of your hot tub like the filter material and the pleats aren’t safe either. The hot water can burn the filter material making it prone to damages quickly.

Also, filling your hot tub with hot water can cause corrosion in the long run. The water that flows through the taps in your home is soft. The water has been treated with chemicals to make it safe for drinking. The chemicals that make the water soft and soft water in your hot tub will cause corrosion and staining.

Related Read: Do Hot Tubs Lose Water?

Will Hot Water Make Hot Tub Chemicals Evaporate Faster?

Hot water will make hot tub chemicals evaporate faster from the hot tub. The hotter the water gets, the faster the water evaporates and as it evaporates from the hot tub, the hot tub chemicals evaporate with the water into the atmosphere.

Hot tubs lose water through evaporation every time you turn on the heater but the rate of evaporation is very slow because hot tubs can’t go above 104 degrees Fahrenheit. But if you add hot water to the hot tub, the higher temperature will cause a faster rate of evaporation and this equals a faster rate of chemical loss too.

When hot tub chemicals are added to the water, the chemicals dissolve into the water to clean it. So when you turn on the heater, you are not just heating the water. You are also heating the chemicals that have dissolved into the water. This doesn’t pose any concern since the rate of evaporation is slow.

Hot tubs only lose 1 inch of water every week during regular use and 2 inches of water under very heavy use. This rate of evaporation is slow due to the maximum temperature of 104 degrees that is set for the hot tub.

When you add hot water to the hot tub, the water temperature will be raised automatically because the hot water you added will have a higher temperature than the water in the hot tub. This will result in increased water loss and chemical evaporation too.

Related Read: Can You Use a Hot Tub With Rainwater?

Can I Fill My Inflatable Hot Tub With Hot Water?

You should never fill an inflatable hot tub with hot water because the inflatable hot tub has more delicate parts that can be damaged when exposed to water temperatures over 104 degrees Fahrenheit.

Inflatable hot tubs are not as durable and strong as regular hot tubs. Most inflatable hot tubs are designed with flexible components made from materials like rubber and plastic. When these materials are exposed to water temperatures of about 140 degrees Fahrenheit, they can get damaged quickly.

Asides from the damages that will occur to the parts of the hot tub, filling an inflatable hot tub with hot water will also cause corrosion to the metal parts of the inflatable hot tub. The water that runs through the taps in the home is soft and has been treated to make it safe for drinking. This soft water can start to eat away at the metal parts of your hot tub like the pump and heating mechanism

You will also start to notice foaming as a result of excess soft water in the hot tub. When foaming starts, there would be staining and discoloration on the shell and jets of the hot tub. Not to mention the possibility of having brown water in the hot tub too.

Filling your hot tub with hot water is never a good idea but keep reading to find out how you can quickly heat the water in your hot tub.

Related Read: Can You Use a Hot Tub During Winter?

How Can You Heat Your Hot Tub Water Faster?

I’m no psychic but I’m sure one reason you are thinking of putting hot water in your hot tub is to save the cost and time it takes to heat the water. But since filling the hot tub with hot water is not a good idea, how can you heat the water faster to save time and cost? Let’s find out.

Use The Hot Tub Cover

One of the reasons it takes hours for your hot tub water to get heated is because the hot tub cover is usually off when heating the water. If the hot tub cover is off, then the heater has to work harder to heat the water because the outer temperature outside the hot tub will be cooler.

The outer temperature cools the water gradually as the heater is heating the water. This means your heater is constantly heating the water while battling the outer temperature too. This makes it harder for the water to get hot quickly.

Also, the hot tub cover is usually insulated. This means that the cover keeps heat trapped in the hot tub. So it doesn’t escape.

Related Read: Can You Use Hot Tub Jets While The Cover is On?

Use The Jets

Another way to get the water hot faster is to turn on the hot tub jets. When the jets are turned on, the water in the hot tub is circulated faster.

This allows the water to be heated evenly. If the jets are off while heating the water, the water wouldn’t be heated evenly and there would be pockets of cold water in the hot tub while other parts are hot.

Use A More Powerful Heater

You can contact a hot tub electrician to help you install a more powerful heater in your hot tub’s heating mechanism. A more powerful heater will heat the water faster by producing more heat in the hot tub.

You can also increase the insulation of the hot tub by installing insulation boards around the shell and cover of the hot tub. The insulation boards will help with heat retention in the hot tub and get the water hot faster.

What Is The Best Water To Put In A Hot Tub?

The best water to put in a hot tub is a treated water hot tub water. You can also fill a hot tub with water from the tap that runs into your home.

There are pool and hot tub companies that deliver hot tub water into your hot tub. These companies will bring a tank to your home filled with treated water that is best suited for a hot tub. They would also fill the hot tub for you but expect to pay for the delivery service.

Most hot tub owners fill their hot tubs with water directly from their taps. This is also not a bad idea. The water from the tap has been treated and is safe for drinking. But this doesn’t make it safe for your hot tub. So if you want to fill your hot tub with water from the tap, you should test the properties of the water first and treat it so it doesn’t damage your hot tub’s components.

Final Words

Overall, you should never fill your hot tub with hot water because there are risks involved that can damage your hot tub and its components.

If you want to get the water heater faster, consider using insulation boards and a more powerful heater. Both of these methods are safer than filling your hot tub with hot water.

So there you have it. If you liked this post, ensure to check out others like it on this website. Have a nice day.

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