Hot Tub Water Circulation

Hot tubs are usually on patios and back porches, exposed to the elements. Every day, bacteria and other contaminants do their best to find their way into your spa water. The great thing about modern hot tubs is that they have a circulator pump that runs to help prevent water from stagnating and becoming a breeding ground for all manner of nastiness. Some newer spa owners may wonder what is hot tub water circulation and its importance. Here’s a few answers to the most common hot tub water circulation queries.


Why Does My Water Need Circulating?

If water stagnates, it’s more likely to become a breeding ground for bacteria. The movement helps things stay clean so you’re not skimming algae off any time you want to take a dip.

Water circulates through the filter in a hot tub which helps to trap errant particles that may be in the water.

It also ensures that sanitizing products like chlorine and bromine are being distributed properly and helps to keep the water chemistry balanced.

During circulation, water is pushed through not only the filter but the heater as well. This helps the water stay at a pre-determined temperature so that the water is ready any time you are.


Should My Circulation Pump Be On All the Time?

Many modern spas are designed so the water is circulated continuously, 24 hours a day. If this is the case, just make sure your pump runs quietly and constantly.

Older spas may run on a timer mode or automatic mode which means it doesn’t run all throughout the day but will kick on at regular intervals. Check your spa owner’s manual if you want to adjust those settings and have it filter more or less frequently.

If your spa has an analog timer, make sure its pins are set to ON or OFF for the time periods you want it to circulate.

If your spa functions on an automatic timer, it will kick on based on the spa’s thermostat, stopping when the set temperature is reached. Some automatic modes will run the pump continuously on low speed.


What’s Wrong With My Hot Tub Circulation Pump?

Runs When It Isn’t Supposed To

If your spa’s heating element is burnt out, the pump may run all the time. Try turning the thermostat to OFF or LOW to see if the pump turns off.

There’s a possibility if it doesn’t stop running that the timer is faulty or something is wrong with the circuit board. Call your local service professional for replacement in that case.


Inadequate Circulation

If your water doesn’t seem to be circulating as efficiently as necessary, there are a few things you can check:

  • Make sure your calcium hardness levels are where they should be. High levels can cause scaling and calcium can build up in your pipes which may affect circulation.
  • Clean your filter. Your filter should be cleaned every month. If there is excess buildup in your spa’s filter, there’s a good chance it will slow down your water’s circulation.
    • If you have checked both of these areas and everything seems to be in proper order, the problem may lie with your pump. In this instance, check with your local spa dealer/maintenance professional for assistance.

The Pump is Running Loudly

These modern circ pumps are designed to run quietly and not move that much water, but if it becomes unbalanced or its bearings deteriorate due to a leak, it can suddenly become very noisy and noticeable. If this is the case, contact your spa professional to have it repaired or replaced before it fails entirely.
Side Note:

The 24 hour circulation tubs do cost a bit more to run in comparison to an automatic pump spa. It’s pretty comparable, though.

As always, if you’re ever in doubt about what’s wrong with your hot tub, call up your local spa dealer and they’ll help you trouble shoot your problems or send out a maintenance person. Hopefully reading this will solve the problem for some of you, no matter your hot tub water circulation woes!
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January 13, 2020

I want to add a outside heater to my spa because I do not want to leave it plugged in 24/7. It takes too long to heat up because I do that. If I buy a pump to pump through the heater, what type do I need to buy to pump out of the spa, through the heater and back to the spa.
Vicki Cook

Rachel Miller
December 23, 2019

So here’s my question, most products say “turn on the circulation system” so I never know if they mean turn on the jets while the product moves around in the water, or just add the product, then shut the lid and be done. And what does filtration system mean, is that the same thing as circulation system? I just bought my hot tub a year ago, so I assume the circulation system is running all the time. Thanks!

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