Spa Air Blower - Further Reading

Spa Air Blower

Venturi Air Pipe

Spas connected with an in-ground pool often have an air blower to provide bubbles through the spa jets. Some spas use water venturi power to suck air through the jets without a powered air blower. On the right you can see a picture of a venturi air pipe with the air intake notch.

Blowers come in 1HP, 1.5 HP, and 2HP models. Bigger is not better for blowers. Too large a blower can overheat and shutdown or blow the water out of the spa.

Vendors for air blowers include:

Spa air blowers are a commodity. They all do the same thing - blow air. The Silencer By Air Supply is supposed to be one of the most quiet. You should shop around for the best price.

Spa Air Blower Control

AS2 Spa Blower Control.jpg

A spa air blower may be controlled by an automation panel with control buttons near the spa or on a control pad.

Or there may be a manual electrical switch near the spa to turn on the air blower. That electrical switch will probably be more then 5 feet from the spa to meet electrical codes.

Another type of spa blower switch uses an air switch button in the tile. The button generates a burst of air, which goes through a vinyl tube to a black AS-2 spa control box[1]. When you push the button, the blower should turn on or off.


Spa Blower Overheating

If there is a restriction in the spa air line, such as a broken check valve, or the blower is too powerful for the air line plumbing the blower can overheat and shut off.

Blower too Powerful

  • Replace the blower with a lower HP
  • Vent the Air Line - If the blower is too powerful you can vent the air line to reduce the back pressure to the motor. You can install a T fitting and a valve on the T to vent some air. Or you can drill holes in the PVC pipe to vent air. The amount of holes needed will require some experimentation.

Water Going up the Air Line to the Motor

  • There should be a Hartford Loop and a check valve in the air line to prevent water flowing up to the blower
  • New installations have had the air line and water lines to the spa reversed causing water flowing up to the blower.

Hartford Loop Improperly Installed

One users fix was the hartford loop was at least an inch below the water line and the plumber had used two sweep 90s. Water flowed back into the air pipe after turning off the air blower, the water filled up the pipe enough that it constricted the flow of air causing the fourth blower to die. They raised the height of the line well above the water line (we were able to verify when the spa blower was turned off that the water didn't go above the pipe) and used two hard 90s.[2]


Hydro Jet Spa Air Water Manifold.jpg
  • The water line and air line run separate to the spa jets and are combined by two inlets at the back of the jet combining the water and air
  • Blower air line should have 2" pipe, not 1.5".[3]