After a number of successful years of self-taught self maintenance, have come through this WI winter with a problem - air bubbles in two of the three return lines. Have tightened down all the connections, etc., and haven't found a great thread on diagnosing the problem.

The only thing besides winterization is that I did accidentally break one pipe in the manifold of the suction section which has 3 pipes merging into the pump inlet. Due to constraints, I had to downsize to 1 inch pvc in this section, where it's 1.5 coming out of the ground. Not sure if that's doing it.

Also was struggling with why only 2 of the three lines are showing bubbles. on the return lines, there are two lines coming out of the heater back into the ground, so logically maybe its the one line that feeds the two return jets. However I have a hard time figuring out how air would be introduced at tthat point.

I've teflon taped the entire room...

Appreciate any ideas....