Spa & Hot Tub Troubleshooting Guide

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Some would say that spas and hot tubs are much easier to deal with than pools, if only because they are smaller.

Problems with spa water can be more frequent, and due to the electronic nature of it's components, diagnosis and repair can sometimes seem more difficult.

Here's a Spa Troubleshooting FAQ of common spa and hot tub issues.

Q: Spa is dead. No lights, no power at all.
A: First, check the circuit breaker for the outlet that the spa is plugged into. If it's tripped, switch it all the way to the Off position, and then back to the On position. If not tripped, check for GFCI electrical outlets on the same circuit that may have the Test button popped out. This outlet may be under your spa, next to the spa controller pak. Push the Reset button in to reset a GFCI breaker.

Q: Spa runs, but heater is not heating the water.
A: Is thermostat turned up all the way? Does the heating indicator light come on? Clean the filter and any strainer baskets. It may be the pressure switch keeping the heater off to protect it from low water flow.

Is the pump pushing out water through the spa jets? The pump may be running but not pumping water due to a low water level, an air lock or an air leak.

If still no heat, check your heater element for a red reset button. If the reset button pops again, or if the water is still cold, remove the heater element and inspect it for cracks or corrosion. Testing the element for continuity with an amp meter can reveal hidden problems. When you reinsert the element, ensure that it does not touch the side walls of the heat chamber.

Q: Spa heats, but doesn't get hot enough.
A: Check that the thermostat is turned up all the way, and that your filter is clean and the pump is pumping at full (high) speed.

Spas have a safety switch known as a high limit switch, meant to shut off a runaway heater that is getting too hot. Sometimes these switches can malfunction, and open at a much lower temperature. If you locate the high limit in your wiring diagrams, you can test to determine if the high limit is faulty. If this does not increase the heat, test the thermostat, to see if this component needs replacement.

Q: Spa Water is dirty, oily or smelly.
A: Drain the spa after 30 hours of use or 3 months, whichever comes first. Replacing the water regularly can make water management easier. Aside from that, poor water conditions could indicate that it's time to clean or replace your spa filter cartridge. Check that your filter cartridge is positioned properly, and water is not bypassing.

Are you running the filter pump long enough each day, on high? Generally speaking, a spa should run 8 hours per day on high, split into two 4 hour periods. Or, a spa may run all the time (24/7) on low speed; switched to high speed during use. You could also use low speed for 12 hours and high speed twice daily for two hours runs. Check your owner's manual for the best advice on your particular spa.

Of course, your water balance and level of sanitizer will have a lot to do with water clarity. Test your water, then adjust if needed, to balance the water pH, Alkalinity and Hardness. Afterwards, a good shock treatment can usually remove turbid water conditions.

If you use a spa salt chlorinator, a spa ozonator or Nature2 for spas, check that these systems are operational and are not in need of maintenance.

Water clarity can reduce from hair products, cosmetics, or lotions in the spa. Also - how do I say this delicately... If you are in need of a shower, it's best to take one before you enter the spa!

Finally, repeated water issues may indicate that your spa is harboring a high load of biofilm bacteria. Use Spa Purge to clean biofilms from your spa pipes and hidden surfaces.

Q: Spa Pump is constantly on high-speed (or low-speed).
A: Most pumps switch speeds when you push the air switch button. The air switch could be the problem, or you could have a cracked or disconnected air tube between the switch and the pump. A stuck contactor or relay, which switches between pump speeds, could also cause this issue. Finally, the motor itself could have a malfunction in the speed switching mechanism.

Q: Spa Pump is very loud!
A: This would indicate the need for shaft bearing replacement. This sound is a steady screeching noise, which gets steadily louder over time. Clogged impellers or broken fans make a different noise, which reduces quickly as broken pieces are worn down. Pump motor bearings can be replaced at an electric motor shop, or you can replace the motor, or the entire hot tub pump if you wish.

Q: Spa Air Bubbles are not coming on.
A: Check the air switch line to the blower for cracks or being disconnected at one end. Is the power on for the blower? They are normally powered by a dedicated circuit, and may have a circuit breaker, in the subpanel breaker box or in the spa pak. Blowers also may have a valve on the pipe beneath the blower, make sure this valve is open.

Q: Spa Air Blower is very loud!
A: Air blowers have brushes and bearings inside which may wear out over time. You can have these blowers rebuilt at an electric motor shop or swap the entire blower out for a new unit.

I hope these tips covered the issues that you are having with your spa or hot tub. In addition to my nearly famous line of spa chemicals, In The Swim carries a full line of spa & hot tub parts - from air switches to vacuum switches, and all of the other spa parts and components mentioned above.

In The Swim makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and In The Swim assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. In The Swim assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.