Trouble with spa

[Low Tide]

Looking for some help from the experts on here.

Background:
Inground pool with raised spa which spills over into pool. Spa is slightly higher than the pump so when take pump lid off water flows out slowly. Have had a lingering issue with DE getting in pool/spa through system 3 filter. Took filter apart and thoroughly cleaned and reassembled. Had a couple small leaks through orings, and I fixed them at the same time. Pump is completely and fully primed.

Problem:
Now when I turn the spa on the water flows into the spa through the returns but there are no bubbles. Bubbles will flow when I turn on the blower and when I turn the blower off the bubbles will continue as they are suppose to. If I turn the spa off for a few minutes and turn it back on, no bubbles again until the blower is turned on.

Bottom line is the bubbles that should be present are not there until the blower is turned on and they will remain there after the blower is turned off. The bubbles are not there when the spa is turned on without the aid of the blower (constantly on or temporarily on).

Let me hear your guestimates.

Thanks

 

[mas985]

Actually, most spas with blowers behave that way. That is the reason they have blowers to help clear the lines of water so the venturis can work. Only really well built spas can operate without a blower. It sounds like you were marginal before and something just put you over the edge. Is the filter pressure higher than normal?

 

[Low Tide]

No. Filter cartridge was just completely cleaned and reinstalled. PSI is 18.

The pool was built in 2012 and has worked perfectly until a couple weeks ago.

Is there by chance some sort of check valve at the venturi that may be leaking?

 

[mas985]

No check valves at the venturi. Not needed because of the vacuum a venturi creates.

Are there any outer fittings installed over the jets (e.g. spinners). You can try removing those first and see if the issue goes away.

Otherwise, it is possible something got stuck in the jet nozzle. In most spas, the nozzle is deep within the spa wall. You can remove them with a long 9/16" socket wrench. Once removed, you can try to flush the lines and remove any debris and see if that helps.

 

[Low Tide]

There are no gizmos over the jets.

I will try removing the nozzles but I have a suspicion that is not the issue either because there are 9 of them and they are all acting identical.

But, who knows. I will report back on this later.

 

[mas985]

Anything that slows down the flow rate could be an issue. However, since you filter pressure is the same as before, flow rate should be the same. Can you remove the blower from the air pipe? See if that helps.

Again, the venturis really are not meant to work when the blower is off and on the pipe.