I have a 1994 Cal Spa. I have replaced all the jet seals and have bled the air out of the lines with enough water to fill a pool. I have a 4hp motor, a circulating pump and a cartridge filter on the suction side. I have diverter switch to switch between jets. While the tub is empty I have blown and sucked air through all jets and have good air flow. When I fill the tub turn on the jets I get no suction through the venturi lines. I can blow air through them when running and it acts like normal. Any help is appreciated.

1. Is this a digital (Balboa Instruments) system?
2. Did this just 'happen' all of a sudden? Or has it been a problem for a while?

It is a manual system and it happens all the time

I received this tub from my nieghbor of course. It never had an air blower motor. I have 2 venturi lines that come to a T and then to a manual air control.

These tubs have a very horrible record for water and air flow/interference due to their design.

The most important thing is to make sure ALL of the jet gaskets are completely intact.

Next - You must really be patient to understand this, as this is a really tough situation to deal with -
This small diagram I made about 10 years ago, http://spasupport.com/airlocks/jetlock1.gif Not very good, but if you expand it a bit you'll `get the picture`.

Some of these Cal Spa's from back then actually had a tendency to cause suction from jets - with full force pressure coming from the pump. But it's due to poor plumbing design. These problems always seem to happen whenever a CalSpa of this vintage is drained and refilled - air lock problems big time. Usually due to low draped hose loops - existing above the pump suction point.

That said, I'd seriously consider pulling all of the jet inserts to make real sure that you don't have a bad gasket somewhere - difficult I know to get to all of them, but you have to do it. It only takes one faulty gasket on a jet to flood the air suction line - rendering the entire air system useless.

These older Cal Spa tubs are really awesome for size, depth and action, but the plumbing design did leave the uninitiated a bit out in the dark.

You've got to think smarter than the water on this one.

I understand your diagram. What is the best way to get rid of the airlock? I originally installed all the gaskets with water in the tub then drained the tub and checked them all again. I have manually blown air through the air line when the pump is running and works great like it should. I have even gotten some suction after doing this but when I turn the pump of I loose all progress. I have been thinking about installing an air blower and using the manual air valve to work the opposite way, open to release air pressure closed for more air pressure. Your help is greatly appreciated. As I am pulling my hair out with this promblem.

If your system is tight, blowing air will not help if you have the type of airlocks that that diagram describes.

What I have done in the past- is to turn OFF, every jet in the circuit except for the last one in the chain. If it's not possible to turn them off, then get some volunteers and plug the jet output(s) with fingers to force the water completely through the system to forcefully eliminate the trapped air.

This sounds really hokey, but it does work. It's about the only thing one can do in a closed system like this and no other way to deal with it.

Unfortunately I can not turm them off. I am assuming I have to do this on oth sides of the diverter switch since they are seperated. Which jet do you leave operational? Farthest from pump or closes to pump?

Farthest.

Thank you for your help. I have the family ready to try it. I will let you know.