OK, I take back what I said before. The flue ducts within the appliances should have been checked but she might have recorded flue not visible in reference to the main SE/U duct. I would have taken that part of the form to refer to flue duct from appliance to terminal (within SE/U duct). Also sounds like she might have gas rated the water heater, so the 29.95kW figure could be genuine.
