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Should My Hot Tub Pump Run All the Time?

By: Author Jeff Campbell

Posted on  - Last updated:

Categories Hot Tub Operational Tips

Your hot tub pump controls the flow of water into the heater. But it also kicks on during the filtration cycles. So it’s not uncommon for it to be on occasionally when you haven’t touched a button. But you may have wondered, “should my hot tub pump run all the time?”

A hot tub’s pump should not be on 24/7. The pump is designed to turn on when the water temperature drops below the setpoint, allowing the heater to raise the water temperature. But it also kicks on during the programmed filtration cycles several times a day.

If it does run continuously without stopping, its lifespan will shorten significantly.

In this article, we’ll explore a lot more. We will find out how to know if the hot tub’s pump is working and what your hot tub turns on by itself. But we will also explore how often a hot tub pump runs.

Let’s get into it.

hot tub pump run lg

How do I know if my hot tub circulation pump is working?

A hot tub pump that is on will be audible when standing near the hot tub. In fact, in poorly insulated tubs, it can be quite loud. But with the cover off, a pump that is working will also cause circulation of the water without any of the jets being on.

The pump pulls water from the filter area through the heater and back to the tub again.

So you’ll both hear it and see movement in the water. As I mentioned above, the pump kicks on because of 2 crucial steps:

  • When the water temperature drops below the set point
  • When the hot tub’s pre-programmed filtration cycles kick in

The filtration cycles are programmed at the factory but can be changed. They may last 2 hours or more and may happen at least twice a day.

It’s a vital part of the tub that is also keeping your water clean and clear, but how often should you change your hot tub water?

That’s what I explored in a recent article I published. I shared how often the tub should be cleaned and how often the water should be changed. But I also revealed how to actually change the water.

Just click the link to read it on my site.

Why does my hot tub turn on by itself?

A hot tub will naturally turn on the pump when it detects a drop in water temperature or when the set filtration cycles turn on.

So, you may notice this several times a day. Let’s look at both of these in greater detail:

Controlling water temperature

The hot tub turns itself on when its sensors indicate that the temperature has fallen below a certain level, saving you the effort needed to do this manually.

They communicate with the heating elements to ensure that the water is heated to the set temperature.

This is the “standard mode” for some models.

Here, the low speed on one pump comes on periodically throughout the day or night when the sensors detect a drop in temperature and the heater comes on.

Controlling the filtration cycles

A hot tub regularly filters the water to ensure it is clean and free of contaminants.

So at least twice a day, and more if that’s how yours is programmed, the pump will kick on to suck water in through the filter area. Any debris in the water (often too small for you to see), will get stuck in the filter.

That’s why regular filter maintenance is crucial.

After a while, those filters can get clogged and slow the flow of water into the heater and could eventually cause the high-limit switch to trip if too small an amount of water is flowing into the heater.

How do you clean and maintain a filter?

It’s actually pretty easy. Check out my recent article where I do a deep dive on all the simple steps. If you follow those steps, you can double the lifespan of your filter(s)!

Just click that link to read it on my site.

That said, with some models, having a hot tub turn on by itself could be a signal that something is wrong, and you may need to call in a technician.

It could be that the hot tub has a defective air switch or a defective electric switch (or both). The heating element may have burned out, the timer may be faulty, or a stuck relay on the printed circuit board.

How often does a hot tub pump run?

Most models of hot tub pumps run twice a day, a cycle of 2-4 hours each for the filtration cycles. But the pump also kicks on anytime the water temperature drops below the set point. This will vary based on the ambient air temperature and how well the hot tub is insulated.

So most pumps run for 2-4 hours each day, in addition to occasionally kicking on for the heater.

But it is okay even if they run for much longer. Depending on personal preference, to save energy, you may want to reduce each circulation cycle and ensure that they’re during off-peak hours.

Speaking of saving energy, you’re probably keen to know how much electricity an average hot tub uses.

That’s what I got into in a recent article, where I looked at whether a hot tub uses a lot of electricity and how much it costs to run a hot tub for a month. But I also revealed if turning down a hot tub saves money.

Just click the link to read it on my site.

You might think that a lot of energy would be consumed if the pump is running for 24 hours and that it’s better to turn it on and off as needed.

But you’d be wrong because a lot of energy is actually consumed each time the pump has to start relative to the energy consumed if it’s running over a long period.

Some models have automatic circulation schedules ensuring they run twice daily and for about 15 to 20 minutes each time. During this time, all the water in the hot tub passes through the filters.

Ideally, you want to follow what the manufacturers recommend, even if it is a 24-hour cycle. They know best.

How do I know if my spa pump is bad?

A bad spa pump will be significantly louder than normal as the bearings could be wearing out. But a drop in water temperature can also indicate a possible bad pump as it may not be pumping water into the heater. Lastly, a hot tub leak could be emanating from a faulty pump.

Spa pumps, when in good condition, operate relatively quietly. However, inexpensive hot tubs are often poorly insulated and can result in a louder pump noise level.

Circulation pumps often last 5 to 10 years.

Of course, some develop problems earlier. Some of the most obvious signs include humming noise from the motor not turning, frozen shaft, bearings or impeller, or defective capacitor. The whining noise stems from worn bearings, while the leaks come from the failure of the pump seals.

Let’s get into how to troubleshoot your pump if they did develop problems. Ensure that you cut the power off before you troubleshoot!

We’ll look at three scenarios:

  • The circulation pump is dead
  • The circulation pump is making noises
  • The circulation pump is barely working

The Circulation Pump is Dead

If the circulation pump shows no “sign of life,” check your topside control panel. It should indicate error codes FLO or HO.

Confirm that power is on and that the breaker or GFCI test button is not tripped.

Ensure that you also check that all the valves are in an open position. The handle for the slice valves should be up, while the one for the ball valves should be parallel to the pipe.

The Circulation Pump is Making Noises

There are 4 culprits if the pump is making noises. They are air in the lines, scale deposits, clogged impeller, and bad bearings.

Let’s look at how to resolve each one.

There could be air in the lines after you’ve just drained the pump. You can loosen the union nut to release the air. Some pumps come with an air bleeder knob. If yours doesn’t, open the lock nut slightly until you can hear air hissing, then tighten it up again as water begins to leak.

You can also remove the filter temporarily and plug the hole with a garden hose. Use a clean cloth or sponge to seal around the hole to force air out.

Lime or calcium deposits can build up over time, transforming a quiet pump into one that’s noisy. Those deposits can be removed with a chemical like SpaChoice Descaler from Amazon.

If you want to manually clean the impeller, close the valves on either end of the pump or if there are no valves, use a hard clamp on the hoses (pipes). Inspect the pipes and the impeller for deposits. The impeller is a rotating iron or steel disc with vanes.

You also want to check the impeller for debris.

Like most things, the bearings inside the pump do age with the passage of time. And at a point, they may start to shriek and squeal!

To be sure that the bearings are bad, disconnect the plumbing from the pump and put it on. If you can still hear the noise, it’s time to replace the ball bearings.

The Circulation Pump is Barely Working

Check to see if the filter is working properly. If it’s not, you may need to replace it. Other causes of low flow may include the factors we’ve explored in the two sections above.

How do I turn off my hot tub pump?

In most cases, to turn off the pump on a hot tub, simply turn the breaker to off inside the nearby disconnect box.

It is not a good idea to turn off power specifically to the pump while leaving the other components turned on.|

This is because the pump is designed to push water into the heater when the sensors detect a drop in water temperature. The sensors and heater will still kick in, but without water flowing through the heater tube, you risk tripping the high limit switch.

But to temporarily cut power to just the pump, remove the front panel of the hot tub. Then simply unplug the pump from the control box. The plug will be similar but a little different from a standard wall plug. But typically, it will just be plugged in and can be easily removed.

So, is it okay to turn off your hot tub when it is not in use? 

Check out a recent article I published where I explained whether you should turn it off when not in use and what to do when you are on vacation. But I also shared how to turn off your hot tub.

Just click the link to read it on my site.

Conclusion

In the article, we found out how to know if the circulation pump is working and why a hot tub turns on by itself. We also learned how many times the pump runs.

Then, we found out how to know if the spa pump is bad. Lastly, we wrapped things up by finding out how to turn off the hot tub’s pump.

As an Amazon Associate, I may earn a small commission from qualifying purchases if you click on Amazon from my site and choose to make a purchase. You can read my complete affiliate disclosure for more details.

Jeff Campbell
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