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Tower duckbill stuck open

The ‘problem’ is that the check valve lips are partially stuck open.  This is usually caused by lye crystals (which can also cause the lips to stick shut, which causes backfilling).

A quick fix is to put the syringe on the valve (just like filling with water) and pull backwards, creating a vacuum that should seal the lips.

If that doesn’t work then I’d dip a toothpick in some olive oil and gently insert the toothpick in through the lips, to  lubricate the inner lips.  You’d do it gently because the inner lips are thin and you don’t want to tear them.

Then do the syringe pull again.  That should do it.

Generally the duckbill check valve lips don’t leak because they are kept clean by the injection of the filling water from the Humidifier.  It’s part of its maintenance.  The water squatting through them washes the lye off them.

You could confirm a leak (or not) by putting your finger on the duckbill check valve input and then turning the machine on at 100% PWM.  if there was a leak, draining away your gas, bubbles in the Humidifier will confirm the leak.

Or another thing that might help is to put your finger over the duckbill opening (temporarily sealing it) as gas pressure builds up in the AquaCure and once bubbling starts release your finger.  The pressure in the machine will then squeeze and hold the duckbill lips shut.

Once clean, the duckbill check valve should work properly.

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