Q.Peach Tree over 7-8 years old and no flowers so far.
In Ottawa we purchased a 2-3 year old peach plant & planted in our yard. Initially it grew very well. But during 2nd year’s severe winter & snow it died completely. However from the roots few branches (about 10) appeared. In the last 2/3 years 3 branches which grew over 6 feet have dried & the balance have grown to over 12 feet high in last 4-5 years, and the diameter at ground level for each branch is almost approaching to 3″. The plant is full with leaves & is spread over about 15 feet & most of the day it gets sun. It is now 5 years that we planted it. Why there are no flowers so far? What should we do? Earlier the same information I passed to Montreal Botanical as well a research US organisation dealing with peaches but did not get any response.

Certified GKH Gardening Expert
The bad news is that if your peach tree was grafted, your tree that grew from the roots probably was the rootstock your peach tree was grafted onto and not a suitable cultivar itself.
Here's an article that explains these terms and concept of grafting:
https://content.ces.ncsu.edu/grafting-and-budding-nursery-crop-plants
You can start over with a new tree, or consider using grafting technique to acquire and graft a selected desirable "scion" on to your existing tree.