I contacted them via Canaduct which I found on Homestars. Had gone thru MANY heating companies to service a lemon/furnace that another company sold and installed. Other companies either could not figure out the problem, or did a Half job, or didn't return my calls. I was getting very frustrated. Finally, Delta was able to correctly diagnose and fix the problem. This year, another problem with furnace, they answered the call at night (I expected voice mail but got a live person!) and came at the promised time the next day. Fixed the problem within half an hour. Polite professional service, at reasonable prices. Very happy to have finally found a heating company that I can trust. Highly recommended.