As the title says, I'm trying to connect my Blackstone griddle directly to my house plumbing. It's already propane, not a NG conversion. I'd think this is pretty simple but I can't find an easy parts list. Any tips? The supply line is already there and is 3/4 in.

I would call a plumber

Ironically, I had a plumber out to do something else (this is the end of a new build). He told me it was super easy but didn't carry the parts. I might swing by a grill store and see if they have what I need.

Determine what size and style fittings you have, then you just need a hose that is long enough to reach the griddle with the correct fittings.

We put this line in the plans for our home and the plumber "forgot" to add it. They will be cutting drywall to run this line and re insulate, drywall and tape texture and paint for this line.

Using my griddle Mother's Day weekend would have been nice, (I had to change bottles in the middle of cooking.

possible that a small LP gas store that supplies propane in your area may have what you are looking for. They sell grills in their offices a lot of times. In Brenham we used to go to Brenham LP gas to get things like this at times.

I would suggest using a quick connect kit. Should be able to get the parts and whatever length hose you need on amazon. The kit will have the fittings to adapt to the blackstone but you will probably need some fittings from home depot to adapt from your 3/4" supply line down to whatever size the quick connect valve is.

That should be all you need to do if your house is already propane. If you are on natural gas, you would likely need to change out the jets or drill them out, if you're comfortable doing that. I'm not familiar with the blackstones but I've adapted propane grills and burners to work on NG. It's pretty easy.

What kind of propane pressure does a Blackstone require? Isn't household propane regulated down to 12 to 14" WC?

My house is on NG so I bought the conversion kit which I think came with a 10' hose with quick connect on one end which worked with the existing stub on the back porch. Was really easy.