Originally Posted by Falcon72
I have the same setup in my TT. It is line "B" I am most concerned with but I think I have two possible solutions in the post above. I am certain on my TT that line "A" drains into the fresh tank and holds no water once the tank is drained. Line "C" is a concern but I saw a procedure online that said you should remove the small screen on the inlet of your city water connection and push in the check valve that is right at the connection point. This lets the antifreeze flow backwards and out this line. I don't know if that is true of FR's but I will check before I start the process. If it is not then I will need to blow this line out with air before adding antifreeze. If you blow the system out 1st from this port then you would not have to worry about it since this line would be empty. I was just hoping not to need to worry about blowing the system out.
Well I see a couple of potential problems.
1. If you only blow out Line A you have to hope / assume there are no low points between the hose connection and entry to the holding tank.
2. You also have to hope / assume the drain from the FW tank to the pump has the pump at the lowest point in that line.
I have read some posts (don't remember where) that someone discovered his factory line from FW tank to pump was high enough on the FW tank to leave 9 gal of water in the tank. If an RV company thinks that is a good way to run water lines I'm not sure if I can trust that the water pump is a low point.
In my coach I think the pump and the FW tank both sit on the same floor level, so unless the water line if fixed to the floow there will almost certainly be a low point in that line that can't be either sucked dry or blown out.
I write a blog on RV tire application and safety. RVTireSafety.com
Also give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV