Spa Jet Water Backflow through Pump Air Vent

[spud]

I'm having an issue where when I put the spa jet pump on, it causes water to back-flow out the air vents near the equipment pad/spa pump. Previously the spa water/air jets have worked fine. I can't quite remember the exact date they stopped working but probably April 2020, shortly after spring opening of my pool. However I use the spa year round.

Here is what I've currently done with no result:

1. Remove and clean the spa jet nozzles. I've taken each out to ensure it is clean, full open and then put back in place. Note, when I do have all the nozzels removed, with the jet pump on, the jets pump water but not air.
2. Blow pressured air in air vent. I've used the reverse air on by shop vac to blow air in the air intake port towards the spa. This did not produce air bubbles out the jet nozzels.

I'm guessing there is some sort of air or water lock in the system. Some how the venturi action that is supposed to work is not.

Has anyone experienced this before and have ideas on how to fix?

 

[mas985]

That is usually an indication of a blockage in the water lines. But you have already done what I would have suggested by removing the jets. What kind of jets are these? Did you remove the nozzles deep inside the spa wall?

 

[spud]

I just removed the nozzle jets directly on the spa wall. I think they are Pentair based nozzles but I'll check.

On you question of "nozzles deep inside the spa wall", I'm not sure if there are inner nozzles. The nozzles I have and I removed to ensure they were clean screw in and out, and are about 6 inches long. They have a separate ability to open and close on the back of the nozzle. I thought that maybe when I was screwing the nozzle back in, perhaps somehow, the mechanism to open and close the nozzle was also causing it to close accidentally. I tried to determine this but its difficult.

 

[mas985]

Post a picture of the fitting you are removing. They are likely all in one fitting with nozzle but I just wanted to make sure. There are many different types.

 

[spud]

Here is a pic of the fitting. Still wrestling with this issue.