There are a lot of things that can go wrong with a hot tub...of course there's no way we could give tips for every single potential problem, but here's a list of common symptoms we've seen over the years, and what you might be able to do to get your spa running again before calling our service professional. Please keep in mind that these aren't the only possible explanations for these symptoms.
Look through the symptoms listed below and either click on one or scroll down for our suggested course of action!

Please note: As with a great many electronic devices and computers, many electrical spa problems can be corrected just by restarting the system!
If you have any questions about the electrical requirements for your spa, please visit our NEC's Electrical Requirements page.

These are suggestions only: If you do not feel qualified or able to diagnose your spa's problem, STOP and call your local licensed service professional. We are qualified and equipped to handle spa problems.

Nothing is operating, though power seems to be getting to my spa.
Possible diagnosis: Access Door Open
Some models will not operate if the door which affords access to the spa's equipment pack is open...often there is a switch attached to the small magnets that hold the door shut, and until those magnets contact each other, nothing will work.
Suggested course of action: Close that door!
Alternate possibilities: Hi-Limit switch tripped off; Timer off; GFCI Breaker on Equipment Pack off; Fuse blown; Faulty Door Switch

I've drained, cleaned and refilled my spa, and now when I turn it on, the pump makes noise but doesn't seem to water flow, and the jets won't come on.
Possible diagnosis: Air Lock
When a spa is emptied and refilled, air is frequently trapped in the plumbing. Since a spa's equipment needs to have water in it to operate, your motors won't pump when there's air trapped in them. Fortunately, once this air is released from the system, everything should work properly.
Suggested courses of action (one or all of these suggestions might be necessary: try to run your spa after trying each one):
  • If your spa's Filter is in a sealed Filter Housing, there should be a small black pressure release valve directly on top of the housing. Open this valve and there should be the sound of hissing air: keep open until water starts to come out, then close the valve.
  • Force water directly into your spa's jets with a garden hose, holding the hose directly but gently up against each jet for 20-30 seconds.
  • Depending on your spa's system, there might be a pipe attached to the highest point of the equipment pack. This pipe should be affixed with a black or white plastic Union Nut, which you should be able to loosen and tighten by hand; make sure the power to your spa is off before trying this. Loosen this nut and listen for hissing air. Again, once water starts coming out, (do not let any water spray on Equipment Pack or Pump Motors), retighten the nut by hand. Be careful not to overtighten the nut, as it will break or damage the piping.

The spa isn't heating, or the water is a lot cooler than it used to be, but everything else seems operational.
Possible diagnosis: Dirty Filter
Your spa's water passes through the filter before it moves on to the heater. If water flow is restricted by a dirty filter or debris in the Filter Housing, the heater may not operate.
Suggested course of action: Remove your filter cartridge for cleaning: carefully check the filter housing area for any debris, such as leaves. Visit our Filter Care page for more detailed instructions on cleaning your filter.
Alternate possibilities: Faulty Thermostat or Temperature Sensor; one functioning Pressure or Flow Switch

The water got very hot but then everything just shut the spa won't turn on, although power seems to be getting to it.
Possible diagnosis: Tripped Hi-Limit Switch
A water temperature of over 105į Fahrenheit is unsafe and unhealthy for spa users. Your spa has a sensor called a Hi-Limit, which is designed to shut the spa down if an unsafe temperature is reached, before the equipment is damaged.
Suggested course of action: Some spas have a Hi-Limit Reset button, located somewhere on the equipment pack, which is designed to reset the Hi-Limit after it has tripped. It can be black or red, square or cylindrical...sometimes it's even hidden towards the back.
To reset this type of Hi-Limit: Press this button, and you should be rewarded with a SNAP sound, which is the sound of the switch resetting.
(Note: Water temperature must be lower than 100į to manually reset Hi-Limit)
If this works and your spa is running again, please keep in mind that something caused it to trip, which may need to be addressed: The Hi-Limit Sensor or Temperature Sensor may need to be replaced, or your Filter may just need a thorough cleaning. Also note that if your Hi-Limit trips and needs to be reset several times, it will probably need to be replaced, as frequent tripping can cause it to melt and distort.
Note: Most newer spas (with electronic controls) have an automatically resetting Hi-Limit Sensor: Water temperature must still drop below 100į and power to the spa will need to be turned off for a couple of minutes to reboot the system.
If Hi-Limit or System will not reset, your Sensor or Switch may be faulty.

Nothing is operating, and I'm seeing an error message on my control panel.
There are as many different error messages as there are different brands of spas. Some refer to a specific issue ("OH" for overheat), while some are catch-all messages for a variety of problems ("FLO" for...lots of things!). Refer to your spa's owner's manual for guidance. If you no longer have your owner's manual, many spa manufacturers now have manuals available at their websites...or you can contact us and we can try to help!

My spa's pump seems to be surging.
Possible diagnosis: Water Level Too Low
Keeping your spa's water at it's proper level is important. Generally, a spa's water level should be about halfway up the filter opening. Add water as needed. Water loss can be due to leaks, but a certain amount of evaporation is also unavoidable. Keep an eye on your spa's water level, and be sure to test your water's chemistry regularly! Visit our Basic Water Care page for tips.
Possible diagnosis: Clogged Suction Fitting/Clogged Pump/Obstruction at Pump Impeller
Suggested course of action:
  • Suction Fitting: Your spa has suction fittings, usually located in the spa's footwell, through which water circulates. Check these fittings for blockage. Some spa manufacturers affix fabric "socks" over these fittings for added filtration...these frequently get clogged, but can usually be removed for cleaning and reattached.
  • Filter: Check and clean your Filter. Visit our Filter Care page for tips!
  • Pump Impeller: Close Pump and shut off valves or drain Spa; Loosen Pump Union attached to suction end of Pump and check for debris. Pump may have to be removed for access to suction end.

My spa is overheating.
Possible diagnosis: Dirty Filter
Most spa's water passes through the filter before it moves on to the heater. If water flow is restricted by a dirty filter or debris in the Filter Housing, the heater will not operate properly.
Suggested course of action: Remove your filter cartridge for cleaning: carefully check the filter housing area for any debris, such as leaves. Visit our Filter Care page for more detailed instructions on cleaning your filter.
Possible diagnosis: Bad Thermostat or Hi-Limit Switch
If a spa's Thermostat and Hi-Limit Temperature Sensors are not working properly, it can think that the spa is overheating, when in fact the water temperature is within an acceptable range. The alternate is also true, that your spa's water can rise without the spa's Hi-Limit kicking out, if the Thermostat is inoperable. We suggest using a floating thermometer as a backup, so that you can have a backup for getting an accurate read of your water temperature. If you suspect that your spa's Thermostat or Hi-Limit are inoperable, please do not use your spa and contact your service professional immediately.

My spa trips the GFCI Disconnect or Main Breaker in my house.
Possible diagnosis: Spas trip breakers for a variety of reasons. Sometimes water is inadvertently splashed onto electrical components, sometimes a breaker is faulty sometimes a sensor is sending a false reading...there are many possibilities. If your spa is frequently tripping a breaker, it likely needs a visit from your service professional. What is often helpful, however, is isolating the problem.
If your breaker is tripping, try to tie it to a specific action:
  • Does it trip immediately when you turn the spa on?
  • When you turn on the heater or jets?
  • When it goes into a filter cycle?
  • Does the spa work normally for a few minutes and then trip the breaker?
Any clue you can relate to your service professional will be helpful.
Please note: According to the National Electric Code, all 240v hot tubs operating in the United States must be hard-wired to the power supply, and be connected to a GFCI (Ground Fault Circuit Interrupter) Breaker, with a Service Disconnect located within sight of the spa's users, but no closer than five feet from the water's edge. 120v hot tubs may use GFCI cord, plugged into its own grounded outlet. If you are unsure about the setup of your spa's electrical system, contact your spa service professional or an electrician.

Water is coming out the top of my spa's filter casing, although it appears to be shut tight.
Possible diagnosis: Pinched O-Ring
Sometimes the O-Ring in a spaís filter casing lid can become pinched or slip out of its groove, which can cause the lid to be improperly sealed, even though it seems tight.
  • Turn off power to spa and remove filter lid per manufacturerís directions (vent off pressure if filter has air relief knob or valve).
  • Check O-Ring. Remove O-Ring and clean it and filter lid O-Ring groove with warm, slightly soapy water: rinse well.
  • Lubricate O-Ring with a silicone- or teflon-based lubricant such as Magic Lube or Jackís Lube.
    Note: Do not use petroleum-based products such as Vaseline!
  • If black debris comes off of O-Ring when cleaned, replace O-Ring with a new one.
Possible diagnosis: Cross-threaded or cracked filter lid
Your filter lid threads onto the filter housing rather delicately, and can sometimes be improperly sealed, even when screwed down tight. Check to make sure it threads smoothly into place, plus you can check for cracks in the filter lid itself.

My spaís pump runs continuously.
In many cases, this isnít really a problem at all!
Many recently-manufactured spas have Circulation Pumps that are designed to run 24/7, constantly filtering the water and keeping it running past the heater to keep a stable water temperature. Sometimes itís hard to even notice that this pump is running, since itís 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 noisy and noticeable! If this is the case, youíll need to contact your spa professional to have it repaired or replaced before it fails.
Older spas frequently operate on Timer Mode or Automatic Mode.
Timer: If your spa has an analog timer, make sure its pins are set to ON or OFF for the time periods you desire.
Automatic: Automatic Mode is usually controlled by the spaís thermostat (automatically turns off pump when set temperature is reached). Some Automatic Modes run the pump continuously on low speed.
If you have a 2-speed pump, make sure it is set at low speed, as high speed can keep it running continuously. Additionally, if spaís Heating Element is burnt out, the pump may run all the timeÖturn thermostat to OFF or LOW to see if pump turns off.
Ultimately, thereís the possibility that the timer may be faulty, or a relay may be stuck on a printed circuit boardÖcall your local service professional for replacement.

Some of my spaís jets arenít pushing out water as hard as other jets.
Possible diagnosis: Diverter Valve
Some spas have Diverter Valves, which control the flow of water to different jets. Usually this is controlled by a knob or handle, located along the top rim of the spa. Frequently we find that Diverter Valves are inadvertently adjusted during a spa cleaning or refill.
Suggested course of action:
With your jets turned on, adjust the Diverter Valve and see if the flow from the jets evens out.
Possible diagnosis: Jet face needs adjustment
Many spa jets are individually adjustable. By turning the jetís face, often its water flow can be increased or decreased. Be sure to never try to force a jet face that doesnít want to turn, as they can break and fill your spa with little tiny pieces of plastic or bearings!

When I turn my spa on at full force, it foams up like a bubble bath.
Bubbles are by no means a sign of trouble, particularly if they dissipate rapidly once the jets are turned off. You should be able to control the amount of air thatís being pumped into the water with the Air Control Valve: Turning this down or off should make things less bubbly.
Additionally, youíll want to make sure that bathing suits are well-rinsed before getting into the hot tub: A very small amount of laundry soap can make a very large amount of bubbles! We recommend all bathers taking a shower before getting into your hot tub.
If youíre experiencing more bubbles than you can handle, and they donít go away in a hurry when the pumps are turned off, this could be a symptom of improper chemical balance or unwanted oils or liquids in your water: Draining, refilling and rebalancing a spaís water is the best procedure in such a case. There are defoaming products you can use, but if the problem persists, we suggest using Spa Purge, an enzymatic cleaner about which more information can be found on our Natural Chemistry page.

My spaís water smells really bad, a musty or chlorine smell. Iíve drained and refilled it, which helped for a while, but it just comes back.
Possible diagnosis: Dirty Plumbing
A spaís water can take on an unpleasant smell for any number of reasons, such as dirty filters or improper chemical balance, but if itís a smell that keeps coming back even after a cleaning, refill & chemical balance, the problem could be in the plumbing. A regular cleaning wonít do anything for the insides of your spaís piping, which can collect all sorts of gunk, particularly if the spa is left empty or partially filled for an extended period.
Suggested course of action:
We suggest a product called Natural Chemistry Spa Purge, an enzymatic cleaner thatís made to get rid of the gunk you canít reach (see our Natural Chemistry page for more information).
Also, keep in mind that chlorine is okay to use in your spa in the form of superchlorinate shock, but that bromine is a much better overall sanitizer for a hot tub. Chlorine works well in pool water, but isnít regulated for use in hot water, where it breaks down and dissipates quickly. We suggest bromine tablets in an adjustable, floating dispenser for your spa!

When I turn my spaís jets on, black (or white) debris shoots out with the water. Iíve tried emptying, cleaning and refilling my spa, but the problem persists.
Possible diagnosis: Deteriorating O-Rings
Older spas can sometimes suffer from deteriorating gaskets and o-rings: If yours are deteriorating, itís quite possible that theyíll all need to be replaced, not only to prevent black debris from floating around, but to keep your spaís plumbing water-tight.
Possible diagnosis: Dirty plumbing
White ďspa dandruffĒ can be the result of organic buildup in your spaís piping, which you canít get to with a regular cleaning. We suggest a product called Natural Chemistry Spa Purge, an enzymatic cleaner thatís made to get rid of the gunk you canít reach (see our Natural Chemistry page for more information).

Having a problem that's not listed here?
Visit our Contact page and describe it to us...we might be able to help!

*PLEASE NOTE* Spa Doc in no way guarantees that these guidelines will achieve the desired results, as every spa has different needs, based on number of bathers, atmospheric conditions, whether or not you have a proper spa cover, whether or not your spa uses an Ozonator, and a variety of other factors. These are basic guidelines based on manufacturer's suggestions and our experience after over twenty years of servicing spas. Please be certain to carefully follow all instructions and suggestions listed on whatever sanitizing and cleaning products you choose to utilize, in addition to suggestions made by your spa's manufacturer.