Originally Posted by campnqueen
Hey y'all figured out what the swith goes to!! To our EXTRA roof vent in the back!!
Still haveing found the fresh water dump or thr water heater bypass... did figure out the inside/outside speaker with t eh Jensen radio. Wewill keep ypi post if anf whe we ifn the others.
Your WH by-pass (as described in a previous post) will be on the back side of the WH (considering the outside as the front).
Go to the wall that the water heater is mounted, look under the counter, you may have to remove a back wall on a shelf. (on mine I can see over the wall) and it will look exactly like this: (mine look like this) -
The valves are open if the long sides of the oval are in line with the tubing. As you can see in this photo the by-pass valve in the middle is closed. My arraignment is exactly like this.
I have the 27UL (the fifth wheel that looks like a horse trailer) so I can't speak to where your heater is located in the 25 ULS but it should be under the kitchen sink area if like mine.
HW drain? really, I don't think I have one, at least not a dedicated one at the heater - I just pull the plug on the outside. Actually my previous camper I had a drain valve that screwed in that same plug and it had a wing nut type valve like car radiators use.
I do have drains for hot water side and cold water side piping that drop down through floor under my shower area. Those tubes are the same PEX type tubing used through out the trailer (Red=hot, Blue or White=cold) just like in the picture so they are easy to see sticking down under the trailer. By draining water there I can drain the entire system (hot and cold) by opening each of them and blowing out the water. If you are concerned about winterizing, the easiest way I have found is to get a "Male water hose to Air hose adapter" like this: Both can be purchases for about 6 bucks on Amazon. (search "RV Blow Out Adapter")
Open the drain valves under the trailer first! Before hooking up air to system.
BE SURE TO LIMIT YOUR AIR PRESSURE TO 20 PSI MAX really all you need is about 10 psi!
I have never frozen a pipe, tube, heater, etc after blowing out the lines. I prefer blowing out the plumbing as opposed to installing "Winterizing Solutions" into the plumbing. When you go to use the trailer again you have to really flush out the system to get rid of the residue. I smelled like "Winterizing" after taking the first shower the only time I used that stuff. And I really though I had flushed it out before the shower. But I guess some was lingering in the system somewhere, so now I just blow it clear and no worries about freezing and it is ready to go after a quick fill and test.
You also reference "Fresh water dump" I assume you are talking about draining the fresh water tank? Mine has a simple short hose at a low point - between the wheels on driver side. I just unscrew the cap on the end of the hose and it drains. Sorry no pics of that - maybe if the rain stops I may go out and take one for you.
Keep us posted on your progress.