4th LED is lit up red, right straw working intermittently

[MaryK]

The 4th LED on my Quadstick is lit up red. I have tried different cords, devices, mouthpiece, tubes, etc with no change. The right straw is intermittently working and still gives LED output for sip/puffs. What else can I do to troubleshoot? 

[Fred Davison]

Have you tried another mouthpiece?

Does it start out off, then gradually turn red as the quadstick warms up?

Red means pressure.  If the tube or mouthpiece is clogged for mp_right, as the quadstick warms up, it will start seeing pressure when the air expands in a blocked airway.

The picture does not show the tubing connections but if the side tube and mp_right were connected to the wrong Luer fittings, and the side tube was clogged, you could get the same result.