Suspected gas leak
Leave the building immediately. Once safely away, call 911, then your gas utility. Avoid operating switches or making calls inside. Follow emergency responders’ instructions.
Other persistent smells
Arrange qualified evaluation for a persistent or unexplained odor. Follow the manufacturer’s operating guidance and stop using equipment that a professional has identified as unsafe.
Take this question into the conversation
“What did you find, what will the proposed work solve, and how will we know it worked?”
This is general educational guidance, not an assessment of your equipment. A qualified contractor must evaluate the actual system.