What happens is that air can be pushed into the pump when you’re filling the tub. After filling, when you turn the tub on, a bubble of air is stuck in your pump which prevents water from being pulled into the pump. Your water pressure sensors detect no or low flow of water and turn the heater off to prevent damage.
The easiest way to prevent an air lock-is to fill your hot tub properly. When filling with a hose, always put the hose into the filter compartment, don’t just throw it into the bottom of the hot tub. The reason is that your hot tub drains are in the bottom of the foot well. When your tub is emptied, air will get into the drain plumbing. When you fill the tub from the foot well, that air can get pushed further into the plumbing. Then, as the tub fills up to the level of the jets, water enters the jet and fills the plumbing from the top. The air in your lines can’t get out and can eventually settle in your pumps where the impellers won’t move it, effectively creating an air-block.
Sometimes, an air block can be removed by repeatedly turning the pump on and off in the hopes that you’ll create enough turbulence to break up the air pocket and push it through.
Always fill your Hot Tub through the filter compartment to avoid air-locks.
If your hot tub has a two speed pump, putting the pump into high speed creates more turbulence than low speed. Of course, if you have more than one pump in your hot tub, you may need to clear all of them. Sometimes, however, the plumbing needs to be opened and the air manually bled out of the lines.
The best way to deal with air-locks is to always fill the hot tube from the filter compartment, so the air in the system will be pushed out before the water blocks the lower plumbing lines
For more information or to schedule a service call to resolve your hot tub problems, contact us at 201-897-7900 or 732-894-4494. You can also reach us by email through this link.