Hot and Cold levers. And Dash AC noise

[bepar108]

2018 37PA, in the water/sewer bay, amongst all the other levers, there are two lever/handles at the top center for hat and cold water. Are these simply main water valve handles? What need would there be for those except to facilitate shutting off the city water source.
Another question I have is regarding the in dash AC. I hear a sound while the unit is operating that may be described as a low pitched winding motor sound that starts as a high pitch and goes to low pitch almost like an air alert siren.
It comes on and off in about 10 second intervals. Is that part of the normal operating sound of the AC or do the rest of you not get this sound?

[photoguy1313]

If I have it correctly from your description, the hot and cold water valves are for low-point drains for the entire coach plumbing. As to the AC noise, it's the fan mounted on the vehicle air conditioning condenser, and the on-off cycling is normal, even though I wish it weren't so audible from the driving position!

[luvlabs]

The two valves you describe are so that you can shut off the water to the hot or cold side to do repairs without having to shut down the whole system.

The noise you think you hear under the dash is actually under the front end of the coach. It is the dash air conditioning condenser fan. With the engine running and the dash A/C on, go outside and stand near the front wheels. You will hear the fan cycling on and off.