I would appreciate some help on a new gargling voice coming from my HVAC furnace (first time using this season - this didn't happen last year).
As shown in picture, there are 2 small tubes coming out of the air handler going into a kind of 'overflow' box (gray one mounted to the unit) which then overflows into the condensation pump. There is a very strange gargling voice coming from these tubes/ gray box, I'm thinking there should not be water in this as it is like trying to pull air inside from it. Is this normal? What could be the issue? The main pump is working fine and draining all water automatically.