Object isn't rotating when I'm trying to move it?

I've made a door that moves up and down, but the door itself turns 90 degrees when it starts moving. So I tried to add a way to keep the object at the same rotation as it moves down and up but I'm not doing something right?

door = script.Parent.Door
debounce = false
open = true --Door open or not open


script.Parent.DoorToggle.Event:connect(function() --This is a bindable function which is fired from another script
	if not debounce then
		debounce = true
		if open then
			for i=10,180 do
				door.CFrame = CFrame.new(door.Position + Vector3.new(0,-0.1,0))
				door.Rotation = CFrame.Angles(0,90,0) --Something is wrong here
				wait()
			end
			open = false
		elseif not open then
			for i=10,180 do
				door.CFrame = CFrame.new(door.Position + Vector3.new(0,0.1,0))
				door.Rotation = CFrame.Angles(0,90,0) --Something is wrong here too
				wait()
			end
			open = true
		end
		debounce = false
	end
end)

I've only recently started learning CFraming.