Gas Smell After Filter Change

[appdude]

So we decided to change the filter today since it had been 1 year almost since we last did it. So we went down and did what we did every year. Take the panels off, Shut the switch off on the gas valve and changed out the filter. However after we completed changing the filter and the panels were back on. I just briefly "sniffed" on top of the furnace where there are little holes. I smelled a faint smell of gas through the holes. Now it being spring/summer, we DONT use the heat, who does lol? We use the fan function or AC mode. I'm a little confused now. What could be the problem?

 

[Dj2]

Have the gas valve replaced, it could be leaking. Have the gas supply pipe checked as well.