There might be an entry for "gasfitters", which is what the trade is
called. However, you usually get referred to them from a Heating and
Plumbing shop. If gas is not common in your area, you may want to look
for an ad that mentions it; otherwise probably any heating/plumbing
outfit will have gas expertise and licenses.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.