Related to my other thread on keeping cool, I'm pretty sure there are two gate valves, I consulted the manual and found the other one. The first was easy to find (fig 11 in attachment), right by the passenger access panel. But the other was trickier. It's up behind the transmission almost (fig 3).
So two things, 1) It seems like I need to get at it from the top floor access hatch maybe? 2) there is not knob / handle on mine like the other side. Is this a subtle hint to not mess with it? Or do they fall off? My plan was just to use some vice grips, clamp them on and shut tat bugger tight and do another test drive soon.
You shouldn't have any hot water flowing in the system with one valve closed. Two valves are so you isolate the engine and the bus system for engine work or bus system work so you don't have to drain the whole system to work on either side.
It's entirely likely the valve stem is broken and you won't be able to close it. It's a real PIA to replace that valve. BTDT!
Does the stub have a square or splined end? If it is not broken off and h as a square end, use an 8 point (double square)socket of appropriate size.
Leave that thing alone!!
As noted by Lee, just close the easy one inside the side door and job done. Note that the defroster heat also will not flow with that return valve closed.
After everything else is done... and you are both bored and in a masochistic mood... think about that other valve again...
More importantly,what is wrong with theheater controls that the control is allowing hot water to pass???
Happy coaching!
Buswarrior
Pretty sure that the electric control valve is normally open so if the electrical side is faulty or disabled then hot water keeps flowing
If it is closed or broken and closed and you open it without draining the engine separate the flow of coolant will mix with probably much newer coolant and contaminate it. If replacing valve either drain both systems separate or replace all. If replacing all it will be about 24 gallons if just the engine about 10 to 12 gallons gallons. Also if you open them up and the system was empty you may have a few leaky hose connection with in the coach. These are all just warnings for you to consider.
Coach heat works great, I know there is fluid flowing of I open the other side.
I'll just leave the one side shut and take it out and see if there is any heat coming from below.