Hello folks, I am from Toronto. I had problems with frozen pipes in cold weather. I usually call residential plumbing for its servicing. Last winter, I got some tips to find frozen pipes from the plumber. It will surely help you.
Turn on all the faucets in your house. If water is running through one faucet, but not through the other, the problem is located along the pipes running between the two. Then leave all faucets open. A small trickle of running water from working faucets can prevent further freezing and help melt the ice. Leave blocked faucets open to reduce pressure on the pipes.
Search for the most likely areas. I think this is your case. Then search the pipes in or near uninsulated crawlspaces, attics, or basements. Frozen pipes can be the pipes near cold air vents or cold concrete. If you didn’t find any, check outdoor valves and spigots.
Outdoor pipes can freeze if it is cold outside. If these tips don’t work, it is better to call a plumber in your locality.