Even if a guest pays for optional pool heating, there is no guarantee that the water will be at the temperature we desire. This is not because the service paid for was not delivered, or a pool heating system isn’t working properly.

In Orlando, just like anywhere else, whether or not it’s a great time for swimming is dependent upon the weather and Mother Nature. And sometimes, even in Florida, there can be a winter cold snap, which makes being outdoors very uncomfortable. Pool heating, even when working well, is not going to change this.

The dreaded winter Cold Snap

You’ve booked your winter-time dream vacation to the warmth of Orlando, but when you arrive… “Horrors!” The dreaded winter cold snap also arrives in Orlando. Unfortunately it does happen once every few years… a mass of winter cold air descends upon the United States from Canada, and temperatures plunge everywhere. Even in Florida. Sometimes it even snows in Orlando! The only consolation you have is that if it is THIS cold in Orlando, it’s at least -30º just about everywhere else!

This can be kind of a bitter pill to swallow on your long awaited Florida vacation… but hey… no problem! If nothing else, you’ve got a heated pool to go swimming in anyway! Right?

But hold on… the water doesn’t feel warm enough to swim in! What’s going on? After all, you’ve PAID for this water to be heated!

It’s time for a frank, honest discussion about pool heating.

As a guest, you may want to know, “How long does it take for pool heating to be effective?”

Effective is maybe not the best word. It is always effective, but efficiency definitely changes depending upon conditions. This is not a simple question to answer, but here is more information than you probably were looking for!

The water coming out is warmish but I’m not sure how much we will be able to enjoy swimming today before we leave in the morning.  We did get to swim a little Monday but the pool temp has been less than swimmable. I know temps like this are not common down here but I thought perhaps the pool heat would still be able to make it swimmable for the cost.

There are a lot of factors involved in heating a pool and having it reach temperature, which in our case is a desired 89º F.

The average heat pump pool heater in Orlando, running successfully and efficiently, can heat the pool water 15º F above the ambient air temperature. So with some simple math, if the temperature is a constant 74º F, then most pool heaters can get the water to 89º. However, most pool heaters in Orlando are not set to 89ºF, they’re set to 82º F because that is what Disney sets their resort pools to, and they’re kind of a big, dominating, set-the-standard kind of presence in the area. But for the sake of this discussion we’ll stick with our desired 89ºF.

If the temperature outside is 74º F, this is barely warm enough where most people feel comfortable going swimming. If it’s not a nice, warm sunny day, most people have little desire to get in the pool. But a day where the high temperature reaches 74º is not at that temperature all day. That is the peak, reached for only about an hour in later afternoon, and then the temperature starts dropping through the evening, to an overnight low, whatever that is, and then starts rising again in the morning. For example, when you get up on that day with a 74º high, it may only be 58º in the morning. Care for a morning swim? The highest water temperature you can expect at 58º air temperature would be 73º. That’s a cold pool!

And that’s only if the temperature never got colder than 58º over night. If it dropped to 40º at the coldest point overnight, there is going to be some lag. A standard pool heater can reach 15º above ambient air temperature, but only given enough time at at least whatever temperature we’re talking about. How long will the water take to warm up? That’s affected by a number of factors.

They are; size of the pool, thermal output capabilities of the heater (measured in BTUs – British Thermal Units for those interested), and the air temperature itself.

Why does the air temperature matter (aside from our starting point to heat from)? Because the efficiency of Pool Heat Pumps drops dramatically as the temperature goes down.

“When it’s 70°F outside (or above), your heat pump runs at peak efficiency. However, when temperatures drop to 40°F, the same heat pump might work at only 60% efficiency. This means heating times increase significantly in cold weather, sometimes doubling or tripling the expected time.”

This demonstrates the compounding effect of cold temperatures on heating a pool.

All information in quotes is taken from https://znfu.com/how-long-to-heat-a-pool-10-degrees/

The pool heaters at our three villas are all over-sized. That’s on purpose. What that means is that they can heat the water to 30º F above the outside air temperature, twice the usual 15º. That is frankly, highly unusual and great performance. It means that they can heat the water to a higher temperature, and in less time, than typical. We do this for our guests because we want them to have a great experience.

Even a great pool heater can’t beat mother nature.

Using the information above, let’s assume that we get the best performance out of our pool heaters (we do), and it takes 8 hours to raise the water temperature 10º F.  If it’s a cool evening… let’s say 39º, and the water is at that temperature, so for simplicity’s sake we have to raise the temperature 50º (to reach our 89º goal), we can expect that it will take 40 hours at peak efficiency to reach our goal. But if the efficiency of the heat pump starts at only 60% because it’s so cool, then that 40 hours increases to 67 hours. Of course, there will be temperature fluctuation as it (hopefully) warms up during the day, but given the long length of time it can take to heat up the pool, the temperature starts dropping again the next evening long before the pool water will have reached the 89º goal. There are only 24 hours in a day, so 67 hours (even if we could run the heater 24 hours a day) is a long way off.

What this tells us is that heating up the pool, especially if it’s cold, can take days. Part of the issue is that we don’t have to just heat the pool, but we have to heat the pipes, concrete and soil around the pool, or they’ll suck the heat right of it, almost as fast as we can put it in.

Why not run the pool heater all night long if it takes so long to heat up the water? Running a pool heater is expensive in Florida. In November 2025 our villa power bill was $250 for the month. In December, with the same outdoor temperatures, but with the pool heater on, the bill hit $825 for the month. When temperatures drop overnight, and the efficiency of the pool heat pump goes with it, the result is that running the heater for a couple of hours in warmer temperatures in the morning accomplishes more than running the heater all night in cooler temperatures, and costs far less. It only makes sense to not burn out the pump and heater, consuming their useful running life trying to accomplish something that can’t happen anyway.

When a guest books pool heating with us, we actually start the heater 2-3 days before the guest arrives, to have it be at temperature when they get to the villa.

 

But sometimes… if there is a cold snap, like the one we are experiencing this week, where we will actually be running the pool pumps (not the heater) all night long just to keep the water circulating so that nothing freezes up, or pipes crack and motors suffer major damage, it becomes impossible to keep the pool warm enough to enjoy swimming. And almost always this is never an issue for guests, because if it’s too cold to heat the pool, no one wants to go swimming because they’ll freeze themselves just stepping outside.

Occasionally, a guest is disappointed that the pool isn’t warm enough for swimming, even if they paid for pool heating. I understand, but the weather is causing the disappointment, not us, and as explained above, there is nothing we can do about it.

So is it fair to charge a guest for pool heating if they can’t use the pool? Unfortunately, yes it is, because our expenses for heating the pool are much greater when it’s cold than they are if it’s warm. All we can do is promise to heat the pool roughly 30º above the outside air temperature, and we do, but we can’t promise what that will result in, or for how long. That’s up to mother nature. So it’s doubly frustrating; the guest is disappointed at not wanting or being able to swim, and we’ve spent more money and incurred more expense providing them something that they likely won’t want to use.

Does pool heating still make sense at these times? Actually, in my view, yes it does, and here’s why…

To begin with, when our properties get booked (sometimes over a year in advance) no one can predict when a winter cold snap will occur. They happen usually once every two or three years, but when is anyone’s guess. But given that it takes 2-3 days to heat the pool from cold, even when things are normal, and can take much longer when things are unusually cold, we spend money getting the pool ready sometimes in situations where the weather turns dramatically a few days after the guest arrives, and they missed their window to use it. We can’t control that, but still incurred all the expense.

But in addition, what if the opposite happens? Even if we are heating the pool 30º above the outside air, but that’s only water at 72º and so too cold to swim, if the weather turns and it gets warmer (which always happens after a cold snap), then with the water already that much warmer we can get it up to swim temperature in just a day or two, as opposed to it taking three-five days, by which point a guest staying for only six or seven days may be gone. So having the water as ‘ready to go as it can be’ is worthwhile, because when it does turn warm, then the guest can swim immediately, rather than having to wait two or three days. Some guests may only get to enjoy the pool two or three days out of their stay, because they are doing other activities, and we know there is lots to do in the Orlando area!

So yes, pool heating is always better, and always effective, but can it guarantee the water will be ‘swimmable?’ Unfortunately not, because mother nature gives no guarantees. And she can be a cool mistress when she inflicts bad weather on our vacation plans!

This is also one of the reasons why we make pool heating optional. A guest can cancel or request it, any time up to three days before their arrival. After that, we’re all… (both the guest and us as hosts) committed in.

On rare occasions, I get a guest requesting something like ‘Can I just have the pool heated on Thursday afternoon?’ Questions like this reflect how people often don’t understand the issues and complexity involved in pool heating and management. All we can do is offer the services and hope for the best. And again, if a cold snap does happen, cool air temperatures most often keep guests away from the pool, so they don’t feel they’ve missed out on anything.

I hope this information is of use to you and helps you feel better about the circumstances. It’s just bad luck, but we tried, and it actually cost us more out of pocket to heat the pool this week than we charged you for it, so in a sense, everyone has lost all around. Most importantly for me, is any disappointment you may feel. We want all of our guests to experience nothing but the best while they are with us, in all ways.

Also see About Optional Pool Heating and Pool Heating has Limitations for additional information.