Buying a Hot TubMaintenanceHot Tub TipsTroubleshootingHealth + Fitness

How to Heat a Hot Tub: The Ultimate Guide

This blog post may contain affiliate links.

So, you’ve got a hot tub and you’re ready to enjoy a relaxing soak. But wait, the water isn’t warm yet! Don’t worry, we’ve got you covered. In this comprehensive guide, we’ll explore the most effective methods to heat up your hot tub quickly and efficiently. Whether you have an electric, propane, natural gas, or solar-powered hot tub, we’ll provide you with expert tips and tricks to get the water to your desired temperature in no time. So grab your towel and let’s dive in!

How Long Should A Hot Tub Take To Heat Up?

The average hot tub will take between 30 minutes and 1 hour to heat up.

However this will vary depending on the size and type of hot tub as well as the outside temperature.

Before we delve into the various heating methods, it’s important to understand the factors that can influence the time it takes for your hot tub to heat up. Here are some key considerations:

1. Starting Water Temperature 

This is kind of a no-brainer: cold water takes longer to get to a comfortable temperature than that which is warm to begin with. If, on the other hand, your hot tub has been running and the water is already warm, it will take less time to reach the desired temperature.

If you’ve just replaced the water in your tub or you’re starting it up for the first time since winter began, you’ll probably be waiting a while. If you’re in a hurry to use it, it may make sense to rig up a pipe from your house’s warm water supply and fill your tub with this to give it a head start. 

2. Hot Tub Cover and Insulation

One crucial element in heating your hot tub efficiently is the quality of your cover and insulation. A well-insulated hot tub with a high-quality thermal cover will help retain heat and prevent it from escaping. Make sure your cover is in good condition, with no cracks or gaps, and always keep it on when the hot tub is not in use. Additionally, consider adding a floating spa cover for extra insulation and heat retention.

3. Should The Jets Be On When Heating A Hot Tub?

In general it’s best to keep the jets off when heating the tub.

This is because the jets can cause the water to circulate too much which can make it harder for the tub to heat up.

However there are a few exceptions to this rule.

If the outside temperature is very cold the jets can help to circulate the water and keep it from getting too cold.

Additionally if the tub is being used for hydrotherapy the jets can be helpful in providing a massage-like effect.

Ultimately the decision of whether or not to keep the jets on when heating the tub is up to you.

If you’re not sure it’s always best to err on the side of caution and keep the jets off.

This will help to ensure that your hot tub stays at a comfortable temperature for everyone to enjoy.

When turning on the jets, they help circulate the water and distribute heat evenly throughout the tub. Ensure all the jets are submerged before switching them on to prevent damage to the system. Proper circulation is key to achieving faster heating.

4. Outside Temperature

The ambient temperature outside plays a significant role in how quickly your hot tub will heat up. Warmer outside temperatures will aid in the heating process. If you’re looking for a faster heat-up time, start heating your hot tub during the hottest part of the day. However, during winter or colder climates, it’s advisable to keep your hot tub running and the heater on to maintain the desired temperature.

5. Water Chemistry

Maintaining proper water chemistry is essential for efficient heating. Regularly check and balance the pH levels and alkalinity of your hot tub to prevent the buildup of limescale and scum. Clean filters and ensure good water flow to optimize heating performance.

Heating Methods for Your Hot Tub

Now that we understand the factors involved in hot tub heating, let’s explore the various methods you can use to heat your hot tub effectively. Each method has its own advantages and considerations, so choose the one that best fits your needs and resources.

1. Electric Heating

Electric heating is a popular and relatively simple method for heating a hot tub. It requires the installation of an electric heater connected to your power supply. While it may take a bit longer to heat up compared to other methods, electric heating is reliable and widely available. Ensure you have the appropriate electrical infrastructure and hire a qualified electrician for the installation process.

To speed up the heating process with electric heating, make sure your hot tub cover is on, and consider upgrading to a higher capacity heater if available.

2. Propane Heating

Propane heating is another effective option for heating your hot tub. It requires either a supply line to your property or a large propane tank in your garden. Propane heaters are known for their rapid heating capabilities, making them perfect for those impromptu dips in the hot tub. However, keep in mind that propane can be expensive to fuel, and tanks have a limited lifespan.

Propane heaters produce fumes when burning gas, so proper ventilation is necessary. If your hot tub is located indoors, ensure the heater is installed in a well-ventilated area or consider an outdoor installation.

3. Natural Gas Heating

For a more environmentally friendly heating option, natural gas is an excellent choice. Natural gas heaters do not emit fumes, making them safer for both the environment and indoor hot tubs. They are also known for their energy efficiency and cost-effectiveness.

Similar to propane heaters, natural gas heaters provide rapid heating, allowing you to enjoy your hot tub sooner. Ensure proper ventilation if installing a natural gas heater indoors or opt for an outdoor installation.

4. Solar Heating

Harnessing the power of the sun, solar heating is an eco-friendly option for heating your hot tub. Solar panels capture sunlight and convert it into energy to heat the water. If you have access to ample sunlight and don’t mind having permanent solar panels installed, this can be a great long-term solution.

Keep in mind that solar heating may have longer heating times compared to other methods, especially during cloudy or winter days. Additionally, you’ll need a way to store the generated energy for use during the night or periods of limited sunlight.

5. Air Source Heat Pumps

Air source heat pumps are a highly efficient option for heating your hot tub. They work by extracting heat from the surrounding air and transferring it to the water. While they may have slightly longer heating times compared to propane or natural gas, air source heat pumps are energy-efficient and can save you money in the long run.

Consider installing an air source heat pump if you’re looking for a balance between efficient heating and cost-effectiveness. However, be aware that the initial hardware costs for air source heat pumps tend to be higher than other heating methods.

Troubleshooting Hot Tub Heating Issues

Despite your best efforts, you may encounter issues with heating your hot tub. Here are some common problems and troubleshooting tips to help you get your hot tub up to temperature:

1. Thermostat or Temperature Sensor Malfunction

If your hot tub is not heating up properly, check the thermostat or temperature sensor. These components may become faulty or water damaged over time. Consult a professional for repair or replacement if necessary.

2. Circulation Problems

Insufficient water flow can hinder the heating process. Check the water level, clean the filters, and ensure the flow and pressure switches are functioning correctly. Additionally, inspect the pump to ensure it is operating properly.

3. Heating Element Fault

If there is power to the heater but it’s not heating up, there may be a fault with the heating element. It’s best to consult a qualified electrician to diagnose and repair the issue.

4. Control Board Malfunction

The control board is responsible for regulating the heaters and pumps in your hot tub. If you’ve ruled out other issues and your hot tub is still not heating, the control board may be at fault. Contact a professional for inspection and repair.

5. Poorly Installed or Damaged Cover

A poorly installed or damaged hot tub cover can result in heat loss. Ensure your cover is properly fitted and in good condition to maximize heat retention.

6. Air Blower Usage

Using an air blower can introduce cold air into the hot tub, affecting the overall water temperature. Limit the use of the air blower or avoid it altogether if you want to maintain a consistent temperature.

7. Faulty High Limit Switch

The high limit switch is a safety feature that prevents the heater from overheating. If the switch is malfunctioning, it may cause heating issues. Check for any error codes or indicators of a faulty high limit switch and consult a professional for assistance.


Heating your hot tub efficiently and effectively is crucial for an enjoyable and comfortable soak. By considering factors such as insulation, heating systems, outside temperature, and water chemistry, you can optimize the heating process. Choose the heating method that suits your needs and resources, whether it’s electric, propane, natural gas, solar, or air source heat pumps. Troubleshoot any heating issues promptly to ensure your hot tub is always ready for relaxation. Now, go ahead and indulge in the warmth and luxury of your perfectly heated hot tub!

“A hot tub, no matter the heating method, is a gateway to relaxation and rejuvenation. Take the time to heat it properly and enjoy the rewards.” – Anonymous