I've had a faint smell of gas in my utility room since I purchased my home almost a year ago. I had to replace the faulty Honeywell gas control valve on my AO Smith gas water heater shortly after I purchased the home. That was easy and got the water heater working properly, but did not fix the gas leak. I've bubble tested every single gas connection in the home several times (including lines for pinhole leaks), but never found the leak. I finally purchased an electronic combustible gas leak detector and found there is gas leaking at the water heater vent pipe that's peaking the meter! This is why I was unable to detect the leak with the bubble method. It's important to note that the burner assembly has a strong clean blue pilot flame and combustion looks ~normal when the water heater turns on. The vent pipe appears to be drafting normally with smoke tests, both with utility room door closed and open. The air intake screen at bottom of water heater is clean and unobstructed. My question is why am I detecting a gas leak in my water heater vent if the pilot is lit and it's burning and drafting properly? Is it possible the burner assembly has a leak somewhere? I'm concerned as there is clearly gas detected at the vent. Any suggestions would be greatly appreciated. Anyone else ever experienced this?