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 the symptom of your interest 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: Tripped breaker; Hi-Limit switch tripped off; Timer off; GFCI Breaker on Equipment Pack off; Fuse blown
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 or Clogged 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
See your spa manufacturer's directions for Filter removal. Remove Filter and restart spa. If spa heats properly, replace with a new Filter, or carefully cleaned Filter. Visit our Filter Care page for suggestions.
Alternate possibilities: Malfunctioning Pressure Switch; Malfunctioning Flow Switch; Clogged Pump Impellar; Closed Shutoff Valve near pump or heater
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 Temperature Sensor
Your spa has two temperature sensors:
  • Thermostat: Controls water temperature settings up to 104° - 105°
  • Hi-Limit: A safety backup if the Thermostat fails. The Hi-Limit shuts off the heater or spa equipment when it detects a water temperature of 109° - 116°.
The Hi-Limit on most newer spas can be reset by turning off the spa's main power supply, and allowing the water to cool to below 100°. Older spas used mechanical Temperature and Hi-Limit switches. This type of Hi-Limit can usually be reset by pushing in its reset button, a red or black button located on the heater or equipment pack (see your spa manufacturer's instruction manual for exact location on your spa). Water temperature must be below 100° before a manual reset of the Hi-Limit.

If the spa has shut itself down before an actual overheat, Temperature and/or Hi-Limit sensors may be faulty.
Nothing is operating, and there is an error code or flashing dots or lights 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.
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 courses 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
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; Malfunctioning Pressure or Flow Switch
My spa trips the GFCI Disconnect or Main Breaker in my house.
Spas trip breakers for a variety of reasons. Some possibilities:
  • Water can be inadvertently splashed onto electrical components
  • Faulty Breaker
  • Faulty Air Blower
  • Check Valve leaking water into Blower
  • Faulty, or wet, Ozonator
  • Faulty, or shorted, Printed Circuit Board
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. A process of equipment component elimination can also be illuminating: Unplugging each device one at a time and retesting the Breaker. As always, however: Safety first.
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 spa's 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 manufacturer's 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 Jack's 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 spa's pump runs continuously.
In many cases, this isn't 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 it's hard to even notice that this pump is running, since it's 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, you'll 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 spa's thermostat (automatically turns off pump when set temperature is reached). Some Automatic Modes run the pump continuously on low speed.
Additionally, if spa's Heating Element is burnt out, the pump may run all the time...turn thermostat to OFF or LOW to see if pump turns off. Ultimately, there's the possibility that the timer may be faulty, or a relay may be stuck on a printed circuit board. Call your local service professional for replacement.
Some of my spa's jets aren't 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 jet's face, often its water flow can be increased or decreased. Be sure to never try to force a jet face that doesn't want to turn, as they can break and fill your spa with little tiny pieces of plastic or bearings!

Some spas have different pumps for separate banks of jets. In this case, a Pump may be faulty, air locked or just turned off.

When some two-speed pumps are operating at low speed, they do not push a noticeable flow of water through the jets. Once turned to high speed, a more noticeable flow will be delivered.

Some spas are equipped with Air Control Valves: Make sure they're open for better jet action.
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 that's being pumped into the water with the Air Control Valve: Turning this down or off should make things less bubbly.
Additionally, you'll 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 you're experiencing more bubbles than you can handle, and they don't 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 spa's 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 Products page.
My spa's water smells really bad, a musty or chlorine smell. I've drained and refilled it, which helped for a while, but it just comes back.
Possible diagnosis: Dirty Plumbing
A spa's water can take on an unpleasant smell for any number of reasons, such as dirty filters or improper chemical balance, but if it's a smell that keeps coming back even after a cleaning, refill and chemical balance, the problem could be in the plumbing. A regular cleaning won't do anything for the insides of your spa's 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 that's made to get rid of the gunk you can't reach. See our Products 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 isn't regulated for use in hot water, where it breaks down and dissipates quickly. We suggest an Ozonator and bromine tablets in an adjustable, floating dispenser for your spa.
When I turn my spa's jets on, black (or white) debris shoots out with the water. I've 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, it's quite possible that they'll all need to be replaced, not only to prevent black debris from floating around, but to keep your spa's plumbing water-tight.
Possible diagnosis: Dirty plumbing
White "spa dandruff" can be the result of organic buildup in your spa's piping, which you can't get to with a regular cleaning. We suggest a product called Natural Chemistry Spa Purge, an enzymatic cleaner that's made to get rid of the gunk you can't reach. See our Products page for more information.
*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.

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