realized i MUST have one this up coming heating season. Was doing a quarterly on a boiler when a visitor came into the boiler room "it kind of smells like gas" I have known for a wile its difficult for me to smell gas, but now i think i am am totally void of smelling it. SOOOOOoooooo, i need a good brand of gas sniffer. something where i can get in the general area and then bubble or with a high and low settings.

guessing this room has about 1/2 mile of gas pipping so to bubble all the joints would be to much time.