212/DC2 service by a Hollis dealer

I recently had my fabulously breathing regulator serviced by a factory authorized dealer before my much anticipated dive trip. When I entered the water I discovered:
1) that at 30+ feet there was a very loud harmonic that occurred with every breath
2) the dynamic adjustment knob just turned and turned both clockwise and counterclockwise having NO influence on breathing resistance
3) the regulator seemed to free flow if I would dive in an inverted position (looking under coral ledges)
4) the regulator did not breathe as I remembered it.

What would cause these problems?

Sorry, I dont know about issue, but I am concerned as i have just ordered four 212's and two DC1's. I have read other posts complaining about harmonics and honking sounds.

I will be watching this thread.

Good Luck..

If I remember right, most of those symptoms come from the wrong cracking pressure. Ask the shop that serviced your gear to increase the breathing pressure. Also, about the knob....it should continuously turn in one direction, with a clicking noise every turn. The other direction, it should stop. Also, with the switch set in the "dive" setting, and the knob fully "forward" you should get the TINIEST of leak through the mouthpiece. Knob fully "back" and switch set to "dive", you should be able to punch the purge valve and it should freeflow after you let go of the purge valve. You should NOT get any freeflowing with the switch set in "pre-dive" setting.

On the switch: "Pre-dive" is away from you. "Dive" is towards you.
On the knob: Rotating away from you makes breathing easier.

Also, check if there is a cap head screw in your adjustment knob. If nothing works, just have them disassemble it and reassemble it again...making sure that they give your reg extra consideration. That vibrating noise is a pretty common thing, but it normally goes away with depth...not worsens. Also, have them check/set the IP to 145.

Hi Scubanutil, Please contact our customer service department at 888-383-DIVE. Depending on the regulator service, there are a few things that could be causing your issues. We can provide a recommendation or inspection free of charge. Best Regards,