National Gas & Oil Conversions, Proudly serving all of Long Island with prompt and professional service.  We do it all… sales, service, installation and upgrades. And we are a National Grid Value Plus installer. We specialize in residential boilers and are an official distributor of Burnham Boilers. We can handle gas to gas and oil to gas conversions. You can also count on us for the inspection and replacement of leaky gas lines and we re-do and retest old gas pipes.  We offer same day emergency service. Give us a call!