greymountain Report post Posted November 5, 2011 I've located a by-pass knife switch under the bathroom sink on my '06 Discovery. Is there another switch somewhere that should be used in conjunction with this one? The owner's manual is not a lot of help. Thanks. Grey Mountain Share this post Link to post Share on other sites
ClayL Report post Posted November 5, 2011 It may be a one valve bypass system. I made the following drawing of the one in my Winnebago. Share this post Link to post Share on other sites
gfs1943 Report post Posted November 6, 2011 Is this a manually-operated valve, or electrical? My Itasca Horizon has a switch for an electrical valve (or valves). I don't know yet whether it works; I haven't found the physical location of the valve. My "automatic winterization system" is not feeding antifreeze to the water pump. I believe, but haven't confirmed, that there is another electrical valve somewhere in the input line to the water pump. Thanks for any help. Share this post Link to post Share on other sites