Just installed fire pit and now getting a whistling sound in the house when fire pit on full range .I'm going to explain what type of pipe and size of pipe..... 4 years ago decided to build a outdoor kitchen during my construction had 1/2inch pipe coming out of my home so I tapped into that using flex tube to black pipe and made connection to bbq worked flawless... and now I was able to build an a fire pit ...now on this construction project I tapped into the existing 1/2 inch pipe from my Bbq .... so what I did was run a tee down with 2 turn off valves ... one valve ging bbq and the other going to the fire pit All this is 1/2 pipe till after the tee split fron there it goes 3/4 flex tube to 3/4inch green gas pipe roughly going out 15feet to my 4x6 fire pit .... the burner is a 3feet by 10inch wide . Not sure if this is normal operation , can someone please explain in if this is okay or will I some professional help in this. Thank you .
I'm assuming when you say "flex tube", you're talking about a flexible gas connector like this.
If so, the whistle could be caused by this connector. You should be able to find "Whistle-free", or "non-whistle" gas connectors, if you search the internet. The other option, is to use rigid plumbing the whole way.
As d.george points out, you'll want to check the manufacturers documentation for the fire pit burner, to determine if the gas plumbing is properly sized. 1/2" is usually only good for a single appliance. You'll likely have problems if you run the BBQ, and the fire pit at the same time.