Did you fill with only concentrate? You need to add water to the full concentrate. When I said I fill with concentrate, it was implied that it was only to compensate for the water still left in the block.
You should fill it with 1 gallon of concentrate, then let the engine run so the water pump mixes it and works the air out, filling until almost full with 50/50 mix. Tweak the mix based on your temp rating with the coolant tool. The coolant should be -35F depending on your climate. For example, if you live in California, you can get away with +32F, but in the midwest, we occasionally get temps below -35, so I mix it to -45F. You should fill the bottle when the engine is warm and the radiator full. Your temps in Canada might vary.