I have a small propane bbq. My last home had a propane tank for home use (mainly fireplace), so I had a line installed from the home tank to my deck so I could utilize the unlimited propane supply. I remember having to change out a valve in the bbq, and I believe also use a different hose. I now live in a house with natural gas with a line to the deck. My question is will I need to make further changes to the bbq for this to work? My sense is that, even though it was a "home supply" of propane, it's still not the same as a home supply of natural gas but I've tried pretty extensive googling and all I can find is in relation to switching a small propane tank bbq to gas ... I can find nothing about the difference between home propane tank hook-up and natural gas.
Just like with kitchen cookers (ovens, hobs, grills), which have a different set of jets for lpg or natural gas, using inappropriate jets won't work properly. Obviously your bbq is jetted for lpg, and works well on that. However, since most gas bbqs are designed for lpg, you probably won't find jets for natural gas that will fit your bbq.
Also, the regulator will possibly be producing a pressure that won't do the job. Best to question the manufacturers/retailers of your bbq - you may be lucky, but somehow, it's doubtful. Bbqs are usually designed to be portable/moveable, and being fixed to a gasline from a house isn't envisaged.
Regardless of what you used to have you need to do the following:
- Check the gas pressure at the outdoor line using a manometer; hopefully it's 6-7 inches W.C. (water column)
- Take apart your burner/igniter system and look at the orifices; they should have an imprinted stamp which says something like .95, .99, 1.02, 1.05, or whatever. This is the size of the orifice in millimeters.
- Convert that millimeter to decimal inches and check out this PDF file
- You will likely end up in the 10-15k BTU range per orifice
- You need to replace that orifice with a different one of appropriate size for your gas pressure which achieves the same BTUs +/- 10%
If you have machinist drill bits then you could in theory drill the orifices larger.
A .99 orifice is about .039 inches so 10.5k btu in propane. For 7 inches W.C. you would need .055 inches (1.397 mm)
Make sure to obey the precise sizes or else you could end up with a grill that catches fire quickly when on high.
I recommend buying a grill specifically engineered to be safe with natural gas. Weber does not provide conversion kits. See https://www.weber.com/US/en/blog/burning-questions/can-i-convert-my-gas-grill/weber-29870.html
Make sure you have a shut off valve on your natural gas pipe. Best of luck.