Hot Tub & Spa
Pump Troubleshooting

The pump is probably the hardest working piece of equipment on your spa. To keep water moving throughout the entire circulation system the pump draws the water from the spa then pumps it on through the filter, heater and back through the jets. Many pumps have a strainer pot or leaf trap that catches any small debris that made it through the skimmer or main drain . By trapping this debris, the pump helps ease the burden placed on the filter, leaving it free to catch the smaller pollutants in the water. This is just one part of a multi-step process to rid the water of impurities before it's sent back into the spa. Keeping your water circulating is one of the best ways to help keep your spa clean. It also requires very little attention from you. You only need to program the system to automatically turn the pump on for a set amount of time each day so all of the water can be filtered thoroughly.


How Pumps Function:

Most pumps are self-priming centrifugal pumps. These pumps must have a vacuum chamber, commonly known as a pump housing. The pump housing must be filled with water in order for any pump to create a vacuum, resulting in your pump pulling the water out of your spa. The pump housing will remain full of water while the pump is on, and will remain full or partially full of water when the pump is shut off.

When you turn on the pump the motor will begin to rotate on high speed, even if you have a dual speed pump. The motor drives the pump impeller, located inside the pumps center portion at the opposite end away from the electrical switch portion of the motor. While the motor is rotating, the tips of the impeller are sealed hydraulically inside of the pump diffuser, this allows self-priming to occur. Self-priming can only happen provided the pump has a diffuser. Some pumps have a separate diffuser, others have the diffuser molded into the pumps cover.

Self-priming pumps are very dependable and simple in design. They require a sufficient supply of water from the spa, and no air in the suction lines. Air could come from a loose strainer cover, a leak in any valve, a pin hole in any suction line or any crack or loose connections in the piping. Your pump should be kept free of dirt and also located where it can be protected from flooding during heavy rain fall. If your pump motor becomes flooded you may have to replace it.






No water in the pump or strainer basket

If you've just drained and refilled your spa be sure to bleed all the air out of the plumbing system.

If your pump has a leaf trap make sure the trap is full of water and empty of debris.

Lubricate and tighten leaf trap 'o' ring.

Check that all valves are open.

Damaged pump

Does the pump sound normal? If it just hums for a few seconds then shuts down, this is an indication of a frozen motor.

Check for debris clogging the impeller.

Be sure the impeller hasn't broken.


Level of water in spa is low

Frequently this results in the surging of water coming thru the jets. Fill your spa.

Pump basket or skimmer basket is clogged

Clean if necessary.

Air leak in suction line

This can be determined by the recurrence of air in the filter. The leak must be found and repaired (the common cause of this problem is a loose pipe at the pump inlet).

Clogged or damaged impeller

Inspect the impeller and clean or repair as necessary.

Valves are closed Check and open valves.
LOW FLOW & HIGH FILTER PRESSURE Dirty filter If you've recently cleaned your filter try running the cartridge with the filter element removed. Replace the filter element if necessary.
Valves are closed Check and open valves.
Jets are clogged Inspect and clean (debris clogging the jets is frequently debris from another part that has deteriorated or broke).
MOTOR CYCLES ON AND OFF Motor is overheating Check ventilation around pump.
Improper voltage * Check for proper voltage at the motor (please see note at the bottom of the page).
Wiring to motor is undersized * Determine and correct. (please see note at the bottom of the page)
Faulty or incorrect electrical connections * Repair as necessary. (please see note at the bottom of the page)
PUMP DOES NOT OPERATE Damaged motor Does the pump sound normal? If it just hums for a few seconds then shuts down, this is an indication of a frozen motor or debris possibly jamming the impeller.
Power switch is OFF * Be sure all circuit breakers, GFCI's and switches are on.

Check for power at the motor and trace wires back till the problem is found. (please see note at the bottom of the page)

WATER IS LEAKING AROUND THE PUMP AREA Damaged/worn o-rings, pump housing, shaft seal or loosened plumbing fittings Determine exact location and cause of leak and repair as necessary.
PUMP HAS BECOME EXCESSIVELY NOISY Low or no water flow Determine and correct.
Bad bearings caused by normal wear or a leaking shaft seal Replace shaft seal and bearings (it may be better to replace the whole motor rather than just the bearings).


Clearing and Air Lock

There could be a number of things preventing your pump/jets from pumping water, however if this began immediately after draining and refilling, it is not uncommon to have air in the pump preventing water flow. This is commonly called an "air-lock", and you'll need to bleed the air out of the system to start the water moving again. If this problem did not occur immediately after adding water to your hot tub, almost certainly this does not pertain to you. Frequently the air can be forced from the pump by putting a garden hose down into the filter compartment and forcing water through the plumbing. If this doesn't work, the air will have to be manually bled from the pump. Look for tiny bleed screws on the end of the pump (see image below). Open (loosen) these bleed screws to allow air to escape. Always do this with the power off and be ready to close them quickly when water begins spray out with the air. If you have a bleed screw on top of your filter, be sure to bleed air from there too. If you don't have any bleed screws (or this procedure doesn't correct the problem), the union on top of the pump can be slightly loosened to allow air to escape (when retightening it shouldn't be more than hand-tightened, very snuggly). After bleeding, try turning the power on again and see if the jets work. You may have to bleed the lines several times before the jets are fully functional, but you should see an improvement each time. As long as you get the majority of air out of the lines and the jets start flowing again, the remainder of the air will work its way out.

If you didn't just drain and refill, and you don't think you have an air lock (you probably don't), try the following;

  1. Is the high speed pump working (not just making noise, but actually turning)? If yes, move onto step 2. If no, check for voltage at the pump. If there is proper voltage, your pump is faulty and needs to be replaced. If there is no voltage, test back to the power source for open circuits or switches.

  2. Is there good water flow out of some of the jets? If yes, move onto step 3. If you don't have good water flow, try the following;
    • Take apart the pump wet end and look for obstructions or a broken impeller.
    • Make sure your filter is not clogged and is clean. If in doubt, try running your spa without the filter and see if there is an improvement.
    • Check for closed or broken slide valves (gate valves).
    • Make sure the water level is not too low allowing air to be sucked through the skimmer.

  3. If you have good water flow out of some of the jets, check the following;
    • Are the jets adjustable? Many jets can be adjusted for pressure and can be individually turned off (typically the nozzle or face of the jet will rotate to adjust).
    • Check for for loose or worn out jet seals, and the nozzles for obstructions.
    • Is there more than one pump, and is it working?
    • Is there a diverter valve, that may operated banks of jets separately, or could it be broken?



Use any of the information contained herein AT YOUR OWN RISK. These instructions are primarily intended for use by qualified personnel specifically trained and experienced in the installation and repair of spas electrical equipment and related system components. Installation and service personnel may be required by some states to be licensed. Persons not qualified should not attempt to install this equipment nor attempt repairs according to these instructions. Please remember that water and electricity DO NOT MIX. If you are not capable of performing a repair yourself, please contact a local spa professional or a licensed electrician in your area.This information is presented for informational purposes only, and we will not be held liable for any injuries that may result from the repair,   troubleshooting or installation of any electrical components in your hot tub or spa.

If you need an exploded view / parts list & diagram of a particular pump, below are links to various pictures we have here so far. If the pump you're looking isn't listed, Contact Us and we'll put it up here for you. If you need a specific part, let us know.

Motor Identification Chart

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