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Why is my spa pool losing heat overnight? | HotSpring Spas

Why is my spa pool losing heat overnight?

You come home after a long day at work, and you can think of nothing better than sinking into the warm, bubbling waters of your spa pool. It’s the perfect way to relax, unwind and spend quality time with the ones you love. But when you step in, you notice the water isn’t as warm as it should be. You’ve invested in a hot tub, not a lukewarm tub.

A spa pool can lose heat for a number of reasons. Perhaps you left the cover off, allowing heat to escape. Maybe there’s an issue with your heater. It could simply be a matter of build quality – if you’ve chosen a more cost-effective spa, it may lack the insulation required to properly maintain heat.

In this article we’ll take a look at common spa pool temperature problems, including why hot tub temperature drops overnight.

Why is my hot tub losing temperature?

The average temperature that spa pools are set to is around that of the human body: 36-37C. This temperature is generally far above ambient air temperature, particularly because hot tubs are used the most when the weather is cold. Your spa pool therefore has to be built well, and to work hard, in order to retain that heat. And in some cases it might struggle to do so.

If you find yourself wondering why your hot tub won't heat up past 35C (95F in the old money), or why it loses heat overnight, there are a number of potential reasons why. A few of the most common include:

Forgetting to put the cover on

Just as putting a lid on a saucepan will help keep heat inside, so too will placing a cover on a spa pool. If you forget to put the cover on, your spa pool water will lose a huge amount of heat to the ambient air, particularly when the weather is cold, so it’s critical that you put your cover on your spa whenever it isn’t in use.

Another factor is the quality of your cover. While some spa pool covers are not much more than a piece of fabric, at Hot Spring we offer high quality covers that feature thick and efficient insulation, further guarding your spa pool water from the elements.

A lack of insulation

Speaking of insulation, does your spa pool have enough? If you choose a more cost-effective option, there may not be enough of a barrier between your spa pool water and the chill of outside, particularly if you live in a cold climate. Spa insulation is an important consideration when choosing your perfect spa pool, and at Hot Spring we offer the most insulated and energy efficient spas on the market.

Cold coming up through the base

Another potential thief of your spa pool’s heat is the surface on which it sits. If you live in a cold climate and place your spa pool directly on cold or freezing ground, the chill can be transmitted from the concrete, pavers or decking into your spa.

A well-insulated base plate, like those that feature on many Hot Spring models, can ensure that the heat of your spa pool isn’t eaten up from below.



Heater issues

Perhaps the issue isn’t one of losing heat, but not having enough in the first place. If your heater isn’t powerful enough, or has an issue, you won’t be able to create warmth, let alone retain it. Common heater issues include:

  • Low water flow: Enough water needs to work its way through the heater and into the spa in order to warm it. If your spa isn’t heating up, you may have a flow or pressure problem.
  • Thermostat issues: The thermostat controls the temperature that your water leaves the heater at. If water feels like it’s coming out cooler than the temperature you’ve set, you may have a thermostat or temperature sensor issue.
  • High limit switch issues: The high limit switch ensures that the temperature of your spa is kept to a safe level. But if your spa isn’t heating, it may be activating too early.
  • Broken heater element: The element is the part of the heater that actually warms the water. If yours is faulty, your spa will be unable to produce any heat.

How do you fix a hot tub that won't heat up?

As we can see from the list above, some spa pool temperature issues are easy to fix, such as religiously placing your cover on top whenever you aren’t using your spa. Others are an inherent part of your spa, such as the quality of the insulation, in which case the only real solution is to upgrade.

If you experience a lack of heat in your spa pool, it could be due to a broken, faulty or underperforming spa part. In such cases, seeking assistance from a professional spa pool technician is advisable. Hot Spring has a dedicated, committed, nationwide network of independent dealers who are there to ensure you’re never without service and support across the life of your spa. Hot Spring® Spas dealers supply spare parts for up to 20 years, and even offer equivalent spa parts beyond this two decade guarantee!

How fast does a hot tub lose heat?

The rate at which a spa pool loses heat can vary markedly. An uncovered and badly insulated spa sitting in freezing temperatures can lose a large amount of heat in a very short period of time. If you have a high quality spa with a small heater issue, the heat loss might be barely noticeable, with the spa just dropping a degree or two below your chosen temperature from time to time.

If you can feel that your hot tub temperature drops overnight, or if your temperature gauge tells you as much, and there’s no obvious reason why, get in touch with a professional as soon as you can. A spa pool that loses heat isn’t just an uncomfortable situation, it can be a costly one too: if your heater has to work harder to get your water warm, your power bills can rise dramatically.



The Hot Spring difference

At Hot Spring Spas, we understand that heat retention is crucial when it comes to enjoying your spa. That's why we take it seriously and our range of spas are equipped with market-leading levels of insulation, high-end covers, and parts designed to last. But that's not all. 

Our Energy Smart® system takes it one step further, providing you with lower operating costs and the best value over time. Our patented pump transfers heat from the equipment compartment to the spa water through the spa jets, minimising energy consumption and recycling heat. We also design our own heaters to maximise the transfer of heat and all of our spa covers are custom-fitted with a tight seal to lock in warm air. With a dense foam core and high R-value insulation, you can trust that our covers will keep the heat where it belongs. And with our SilentFlo 5000® circulation pump, which uses less energy than a 40-watt light bulb, your spa water will continuously circulate, ensuring maximum efficiency. 

At Hot Spring® Spas, we've thought of everything so that you can relax and enjoy your spa to the fullest.

Ready to experience the Hot Spring difference? Book your free test soak today!

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