How Long Does it Take a Master Spas® Hot Tub to Heat Up?

If it's the first time turning your unit on it can take upwards of 24 to 48 hours before your hot tub reaches an optimal temperature. That’s the general answer to the question of "How long does it take a Master Spas® hot tub to heat up?" But, as a fellow hot tub owner, you know there are plenty of variables that affect how quickly a hot tub heats up (or doesn’t). We will dive into all the things that can alter the heat-up time of your hot tub, and make recommendations on how to get your Master Spas® hot tub to heat up faster.

If you’re the proud owner of a new Master Spas® hot tub then you likely cannot wait to start enjoying your hot tub. Not only will this article give you something to do while you wait for your hot tub’s water to reach an optimal temperature, but we'll also throw in a few helpful tips that you can use in the future.

Really, How Long Does it Take to Heat a Hot Tub?

If it’s your first time getting your hot tub up and running then you should know that it does take a bit of time for your hot tub’s water to heat up initially. Depending on the size of your hot tub and the efficiency of your spa heater, you can generally raise the temperature about 5 or 6 degrees per hour. So, if the water coming out of your garden hose is at 55º F, then you can see how slow the process can be. In fact, it can take anywhere from one to two days before your average-size hot tub is hot enough for use.

Why Does it Take So Long?

Most people have a hard time grasping why it takes so long for their Master Spas® hot tubs to heat up. Some are even left to believe that they receive a defective unit and hurriedly begin calling their spa dealer to rectify what they believe is a serious issue. While technologies and modern appliances have certainly changed, heat is still heat and water is still water. Also, many people assume that since water is such an excellent conductor of electricity then it should also heat easily as well. But, these are actually two separate phenomena. Just think of how long it takes to heat up a gallon pot of water on the stove top and then multiply that figure by several thousand and you will soon realize why it takes so long for water to heat.

Liquids such as water also heat differently than solids. With liquids, you have all those molecules swirling around, so as soon as one molecule is heated, it instantly begins losing heat energy because it is sharing that heat with the surrounding molecules of liquid and air — just think of how rapidly a cup of coffee cools down. Think about a day at the beach. The air is hot, the sand is burning your feet, but then you jump into the ocean or lake and it is much cooler. This is just one other example of how poor water is in terms of heat conduction.

Of course, ambient temperature, hot tub heater, season, size of the hot tub, and the temperature of the water being heated all play a part in how quickly your hot tub will heat up.

How to Heat Your Hot Tub Faster

There are all sorts of add-ons out there designed to speed up the hot tub heating process — everything from wood burning to solar-powered heaters. But, we’d like to mention two conventional ways that you can reduce the amount of time it takes to heat up your hot tub. Of course, one of the best ways to keep your hot tub ready to use is to keep it either always on or on standby mode. Standby and sleep modes will keep your hot tub’s water circulating while also heating your hot tub to about 20-30º F less than the optimal temperature. By using a standby setting, you will cut the amount of time it takes to heat your hot tub from several days to just a few hours.

How Do Electric Spa Heaters Work?

These days, most residential hot tubs are heated using an electrical heating element. This heating element is installed inside of a stainless-steel cylinder and typically somewhere after the water filter (if you’re thinking of its location in terms of circulation flow). This heating element is controlled by a thermostat, which features a shut-off sensor and high-limit temperature gauges to ensure the water doesn’t burn users (or damage your hot tub’s expensive equipment).

As the water circulates throughout your hot tub it travels through a series of pipes, moving through the skimmer, three-way valve, filter, and finally into the heating unit itself. This is a process that takes quite a bit of energy and patience. But, soon enough you will have your hot tub all nice and toasty and ready for use.