This has been one of my biggest questions I have received from plumbers and gas service people.
There are many different company's making regulators and for the most part there all good. I found these two company's to be one of the best I have used for natural and propane gas.
Pietro Fiorentini 3/4" black spring 2 pounds in 8 to 14" out F31052-2BP
Mec 10 pounds in 2 pounds out #MEGR-1622E-DFF
Mec 10 pounds in 9" to 13" out #MEGR-1652-DFF
If you would like to ask a question or would like a Rinnai guy sticker please send your info to [email protected]

I hope you enjoy this video,
Mike

PLEASE USE A LICENSED PLUMBER TRAINED IN RINNAI LEVEL THREE TRAINING. FOLLOW ALL NATIONAL AND LOCAL GAS AND PLUMBING CODES AND TO FILE A PERMIT AND OBTAIN INSPECTIONS FROM YOUR LOCAL BUILDING DEPARTMENT.