Airgap faucets may be a code requirement to prevent cross-contamination of your potable water. I would look into that first and get it corrected if necessary.

The gurgling is normal. It is the sound of the waste water running to drain when the RO is making water. With the new sink the drain connection may be in a different place and the sound more noticeable.

Thanks, justalurker. I'll look into this and see if I can find out what the codes are.

I suspect the air gap was required because it was there originally. I've seen many RO installations that have a non air gap faucet when code clearly calls for an air gap faucet. When questioned, the installers are reported to say "it's OK" and if/when inspected the plumbing inspectors say "NO WAY".

An air gap faucet is a safety requirement not just required for the fun of it. There is no down side using an air gap faucet when it is not required but it can be dangerous using a non air gap faucet. That's why most quality RO units come with an air gap faucet now days. Cheap, anonymous ROs tend to come with non air gap faucets.

I am curious, who said "they could adapt a non-air gap faucet to work"? Was it a licensed plumber or a Culligan employee?

It was the Culligan employee. Can you tell me how it's "dangerous" not to use an air gap faucet? I'd like to have a better understanding of this, explained in layman's terms. Thanks for your interest, justalurker.

In layman's terms an air gap prevents cross-contamination between the drain and your potable water. Lots of nasty things live in your drain and the connecting sewer that you don't want to be drinking.

Google is your friend and here's a little light reading... click here to read about air gaps in plumbing

We just installed an air gap faucet and its making the gurgling noise every 10 seconds or so .... is this normal? I read that it can do this for up to 7-10days ?