Furnace Liner Install Looks Loose

[bipsic]

Had a chimney company install a liner in my chimney per code for a new (gas) furnace install. They broke out a part of the ceramic liner at the bottom to attach the pipe from the hot water heater and the furnace. They flexed the liner to 90 degrees through the cinder block wall, and then used sheet metal screws to attach to the pipe. As you can see from the pics, there is about an inch gap at the top when I look inside there is a bit of white excess ceramic fire wool used to secure the top kit. Sent them these pics, they said it was normal to have a gap between the liner and the collar, this is not for a wood stove, just a gas furnace, so it does not get nearly as hot as my fireplace insert. Does this look OK?