I have a 16,000 gal plaster pool/spa spillover combo. The spa has a 1 1/2" drain at the bottom that leads to the main 3/4 hp whisperflo pump. The pumped water goes through the filter and heater then returns to the spa on a side wall inlet. I also have a 2 hp whisperflo dedicated spa jet pump With 2" PVC piping. There is also a 1 hp Mariah blower by Hydro Air that is separated by a jandy valve that controls air flow between the floor of the spa or the side jets. The dedicated jet pump is fueled by (2) 2" drains at the bottom of the spa. I have 4 jets. Jets 1, 2 and 4 work great. With just the dedicated pump on, the water shoots out with great power. Jet #3 on the other hand, is auctioning the water from the spa. When I add in the air from the blower, once again, jets 1, 2 and 4 work perfect. Jet 3 shoots out a lot of air that merely bubbles to the surface. Still no water from the dedicated pump.
Today, I shot air from my compressor through the jet towards the pump. First, I closed the jandy valve for the blower side jets to create pressure and capped all the other jets. The air from the compressor went into the pump filter basket area from the jet with no problems. No evidence of any debris. I then tried it the opposite way and the air came thru the jet. So why am I not getting any water in that jet, and even worse suction? Could it still be possible the pipe is clogged? If so, what do I do? Or is this some type of auxillery suction pipe to augment the floor drain?