Loading... Please wait...

info@hottuboutpost.com or (512) 464-1232

  • My Account
  • Order Status
  • Contact
  • Parts by Spa Brand

Categories

Hot Tub Club Signup


Hot Tub Air Lock Pump

Hot Tub Airlock - Pump Won't Work

air lock spaWhen filling a spa for the first time, or upon refilling the spa after draining it, the main circulation pump that brings water in through the filter and skimmer and routes it through the heater and to the jets, may not prime properly. 

This situation is known as an "air lock".

When the jet button is pressed and the pump tries to prime itself and fill the plumbing and cavity around it with water, an air pocket may be trapped, causing water to not flow properly. 

How to Avoid an Air Lock

One way to help avoid an air lock is to fill the spa with a garden hose placed into the skimmer or filter area, rather than filling it up from the footwell.  Otherwise, it is good to have some channel locks (large pliers) on hand in case one of the pump unions needs to be opened a little to allow trapped air to escape once the spa is full of water.

Pump Priming

With Balboa and other brand hot tub controls, upon startup, after a power outage or upon restarting the spa, the pump will go into a priming mode before the spa starts up.  This can be about 4 minutes on many models with Balboa controls.  PR or priming code will appear in the display.  Now we may curiously stare at the silent spa during those 4-minutes, but what you really need to do is MANUALLY PRIME THE PUMPS one at a time.

Priming a Pump - Newly filled Spa

You see, hot tub dealers often don't inform their customers about all the little features of the Balboa control system. Most people just stare at the priming message and hope something is trying to get the pumps started. 

Well what you are supposed to do during those 4 minutes in priming mode (PR) is to turn each pump on high speed and check the water flow manually, one at a time.  D

uring this startup check if you find one of the pumps with an air pocket or not primed properly, try pressing the start and stop button (jets button) repeatedly a few times to see if that wiill help purge any remaining air out of the pump.

If the pump is a two speed pump, run it on high for a few seonds, then turn it off and then back on through low speed to high again.  If after a couple tries this does not work, and you have determined there is an air pocket inside the heater (in the case of pump 1 being a 2 speed pump that circulates water through the heater), then you may need to slightly open one of the heater unions until the air escapes and water starts coming out, then quickly retighten (but avoid overtightening).

After the initial priming mode is over, normal operation to the spa is restored.  If the pump sounds like it is running, but water is not moving correctly or if there is an error code on the display, the pump may still not be primed properly and there may still be an air lock.  Turn breaker off at this point and restart for another 4 minutes of priming mode to attempt to purge the trapped air.

Open pump unionA quick solution is to start and stop the pump going from low speed to high speed and back off a couple of times to see if air can be purged that way. 

Try it in rapid succession and then let pump run on high speed for about 5-10 seconds and then back to off and then back to low and see if the air pocket works its way out of the plumbing.  Do not do this too many times though, just a couple to see if it will work.

Otherwise the pump union nut may need to be opened slightly with a large pair of pliers or channel locks to let the air seep out that way. Don't open it too much to avoid Niagara Falls under the spa cabinet. 

Just a little opening is enough for air to seep out until the water starts coming out, then retighten. Do not overtighten this union or it can crack. 

If you run into trouble, turn the spa power off and then locate the service valves on either side of the pump to stop the water from flowing if they are available.  Do not close the service valves with power to the spa on!

If you don't have large pliers or channel locks, then this video shows an alternative to opening the union with a screwdriver and hammer. Be careful not to crack the union either when opening or closing it. Pliers are definitely the better solution, but this can work in a pinch:

 Be careful when backing off the 1 1/2", 2" or 2 1/2" pump union on the discharge side of the pump.

Pump Priming for Circ Pump Systems

Startup in Priming Mode - Balboa

If your spa is equipped with a 24-hour circulation pump instead of using the low speed of a two speed pump for circulation duty, then start the jets (pump 1) first - that will turn on the circ pump.  Now both pump 1 and the dedicated circ pump are running. Verify that water is flowing out of both of their outlets into the spa.  If you are not sure, then momentarily turn both pumps off (by pressing Pump 1 button multiple times) to help prime the pump with water.  Do not do this more than 5 times and do not let pumps run for more than about 2 minutes if not primed. 

If you still can't tell if the circ pump is working because the water flow from pump 1 is obscuring it, then you can press Temp button once to exit the priming mode. You should see the circ pump only running for a minute. If you can't see water coming from the circ pump outlet, turn power to spa off immediately - because after that circ pump starts, the heater will want to come on in a minute and you have a potentially dangerous, dry heater condition.  If you do see water, great, it works!

Note that once you exit priming mode, you can't go back into it without restarting the breaker/power to spa.  If you did have to turn power off to the spa because the circulation pump was not working, Balboa recommends to leave the spa off for a couple of hours and then try the whole startup priming process again. Sometimes just letting the water rest will allow it to seep into remaining crevices and your next attempt will be more fruitful.

Balboa Note:

"The circ pump turns on by itself (without you needing to press a button).  So before pressing any buttons, verify that water is flowing from the circ pump outlet.  If it's not flowing after two minutes, turn the power off and let the spa rest for a few hours, then repeat.  If water is flowing from the circ pump outlet, proceed to test all the other pumps."

Once the circultation pump is primed, you can go about testing all the other jet pumps to be sure they are all working.