Hot tub jets not working or weak: what to check first

Common symptoms

• Every jet is weak, even with the pump on high speed.
• The jets surge: strong, then weak, then strong again, often with a gurgle.
• Some jets blow hard while others push almost nothing.
• All the jets on one side of the tub are dead.
• After a refill you hear the pump run, but little or no water comes out.
• The jets run for a while, then shut off by themselves.

Quick checks before anything else

• The water is about 1 inch above the highest jet, the level Hot Spring uses.
• The jet faces are turned open and the diverter lever is not pushed all the way to one side.
• The filter cartridge is clean. If you are not sure, pull it and run the jets for a minute.
• The pump is on high speed. One press of the jets button often gives low speed.
• The panel shows no flow message, such as HFL, LF or dr on Balboa or FLO on Gecko.
• Nothing covers the suction fittings in the footwell or the filter area.

What makes hot tub jets weak or stop?

• Low water The pump pulls in air with the water, so the jets surge and gurgle.
• Dirty filter Every jet gets weaker over days or weeks, and moving jets slow down.
• Airlock A pocket of air trapped in the pump or pipes after a refill. The pump runs but moves little water.
• Closed jets, diverter or air controls Some seats are strong and others are weak.
• Pump on low speed or timed out The jets feel soft, or they stop after a set time.
• A pump that is not running All the jets that one pump feeds go dead at once.

Step-by-step: hot tub jets not working

We start with the free checks, then air in the pipes, then the pump. Go in order: low water or a dirty filter can look exactly like a bad pump. For how the system fits together, see our hot tub pump, jets and GFCI guide.

1. Top up the water. Hot Spring says weak or surging jets point to a low water level or clogged filter cartridges. Fill to about 1 inch above the highest jet. Run the hose into the filter compartment, not the main seating area: Hot Spring warns that filling through the basin can cause an airlock.
2. Open the jets and the diverter. On many jets you turn the faceplate to raise or lower the pressure, so a closed face feels like a dead jet. The diverter is a lever or knob that sends water to one group of jets or another. Hot Spring’s start-up guide sets every diverter to the middle. Balboa lists too many closed jets as a cause of low flow.
3. Open the air controls. Air controls are knobs or levers on the top edge that mix air into the jet stream for a stronger feel. Hot Spring names a closed air control as one reason its moving back jet slows down. Open them all the way while you test.
4. Clean or replace the filter. Turn the spa off or put it in hold mode first. On Balboa panels, hold mode stops the pumps for 1 hour so you can work on the filter. Hot Spring says to clean the cartridges monthly, because a dirty one cuts flow to the jets and can trip the heater’s high limit, which shuts down the whole spa. Low flow from a dirty filter is also a common reason for a hot tub that is not heating.
5. Switch the pump to high speed. On two-speed pumps, the first press of the jets button usually gives low speed and the second gives high. On Balboa tubs without a separate circulation pump, pump 1 runs on low by itself during filter cycles and to check the temperature, and you cannot turn that off from the panel. You can still press the button for high speed. Soft jets during a filter cycle are normal.
6. Clear an airlock. If the jets went weak right after a drain and refill, air is the likely cause. On Balboa systems, turning the power off and on starts a new priming session; then run each pump on high. Hot Spring says that if jets surge, turn them off, wait five seconds, and turn them back on. Balboa says never to let a pump run without priming for more than 2 minutes.
7. Bleed air at the pump. If priming does not clear it, Gecko’s troubleshooting guide, written for service techs, has one more method: with the pump running, slowly loosen one of the union nuts (the large threaded rings that join the pump to the pipes) to let the trapped air out, then tighten it again. Water will spray and you are next to live equipment, so leave this to a tech unless you are comfortable doing it.
8. Read the panel. A flow message tells you the control has noticed the same problem. Gecko’s FLO means no water flow was detected while the main pump ran. Balboa uses HFL, LF and dr. For all of them, the makers point to water level, closed valves, a blocked filter and trapped air first. Look up any code on your panel in our hot tub error code lookup.
9. Check whether the jets simply timed out. Pumps you start with a button shut off on their own. Gecko’s in.k200 keypad turns pump 1 off after 20 minutes by default. Balboa says a pump left running turns off after a time-out period, which for pump 1 low speed can be as long as 4 hours on some systems. Press the button again; this is not a fault.
10. Find the pump that feeds the dead jets. On tubs with two pumps, each pump drives its own set of jets. Press the button for the dead side and listen at the equipment door. Silence, a hum, or a pump that starts and cuts out is a pump problem. Gecko’s guide has a tech check the fuse for that pump, then the voltage at its output: 120 V for a 120 V pump, 240 V for a 240 V pump. Our hot tub pump not working guide covers that side.

Balboa vs Gecko vs Hot Spring: what changes

Balboa. Every power-up starts a priming mode that lasts 4 to 5 minutes on the TP500S panel, with the heater locked off. You run each pump by hand, then press Warm or Cool to leave early. Afterward the panel needs about 1 minute of flow through the heater before it shows the water temperature.

Gecko. At start-up the in.flo sensor checks flow while pump 1 or the circulation pump runs for 2 to 5 minutes, and the screen shows dashes. Weak flow brings up FLO. The pumps are protected by fuses in the control box, and which fuse covers which pump depends on the model, so one pump can stop while the rest of the tub works.

Hot Spring. These spas use their own controls and indicator lights. The start-up steps run the jet pumps on high for one minute to push air out, and priming is done when the jets are strong and do not surge. A SmartJet lever diverts the water and a Comfort Control lever sets the air.

Before you buy any part, write down the spa model, the control pack model and the pump label.

When to call a pool or spa pro

• A pump still will not prime after you have cycled it off and on 5 times. Balboa says to shut off power and call for service.
• A pump hums, stays silent or keeps shutting itself off when you press its button.
• The jets stay weak with full water, a clean filter, and every jet and valve open.
• The breaker or GFCI trips when the jets start; see hot tub GFCI keeps tripping.
• Water is pooling inside the equipment bay.
• Any fix needs the control box opened. Hot Spring says there are no user parts inside.

Common questions