/diy/ - Do It Yourself

Do you know any reliable gas leak detectors I can find on ebay or amazon? handheld is fine, but I don't mind a permanent setup too. I need for a normal house installation, there's an external boiler and since last few days I'm feeling like there's gas odor in the air in the room adjacent to it. Could be the washing's machine discharge too (it's right next to the boiler) so I want to check whether there's a real leak or not, because calling the expert at this time of the year is kinda costly, usually the free check from the boiler's brand company comes once a year in october but I was absent last time.