Winnebago ERA 70A Drain Valve Location

I have the 2016 70A also. does anyone know if it has a water filter. I assume a cartridge type. I looked and could not locate one. I did find the two valves at the very back of the drivers side under the bed at the floor. anyone know what those do or are for. I turned them but am not sure why? I bypassed the hot water heater. I don't know if I got the pink stuff into all plumbing? It came out of all faucets. kitchen sink cold and hot; bath lavatory cold and hot; shower c and h; commode; outside wash/shower c and h; and outside below the chassis/under the running board cold and hot; I drained the hot water heater and wet vacuumed any remaining water in the hot water tank;
We may get to 32 tonight in upstate SC so I want to be sure I have it done properly. Thanks for any advice.