Frozen pipes inWinnebago 36Y

What I found regarding pipes freezing in a 2015 Winnebago 36Y Vista may also apply to other models with a 'sideways' rear bed. When camping on a cold (20 degree) night, we had the utility compartment water pipes freeze up. I complained to a Winnebago phone agent but didn't get any useful info other than the compartment was heated to prevent freezing. Obviously it did not work in my case. The agent was unable to explain to me how it was heated. I started looking with my mirror on a stick and wasn't able to see any ductwork for that but saw there is a hole at the top of the utility bay that wiring and pipes pass through. Further examining found that at the base of the nightstand areas, under the edge of the bed on each side is a 6"x6" grille. The one on the left side of the bed is also access to the water heater bypass valve. They lead to a space under the head end of the bed. The grilles are apparently how warm air is supposed to find it's way from the coach to the utility bay. I had both of them off on our next cold weather outing and found that without them on, 20 degrees outside only lowered the utility bay to 40 degrees (remote thermometers are handy for this!). I also noticed the pipe/wire pass through was almost completely filled with wires and pipes. That, along with the air flow restriction of the grilles were enough to allow the freezing of the pipes. My next project will be to make a second hole to allow more warm air to the utility bay. Stay tuned...