Can I Close My Low Point Drain?

valhalla360 wrote:
The low point drain shouldn't be open but many trailers have an overflow hose that will allow excess water out if you try to overflow the tank.

It may be worth checking how full the tank really is. It's not uncommon for the overflow connection to be well below full. We had a trailer where the 40gal fresh water tank would syphon off almost 10gal if it started overflowing. Not a big deal if on a full hook up site or boondocking for a night but if you are off water for multiple days it's a nuisance.

Added a simple valve to the end of the overflow hose. Typically left it open so it would still perform it's purpose but if boondocking, I would close it once it started to overflow (and obviously stop filling the tank). This allowed full use of the tank when boondocking for multiple days.

My new Wolf Pup had this issue. The builders didn't bother to run a vent hose up to the water filler vent like they did on my old popup, but just left the tank vent fitting open to dump out from underneath. It was below the full level of the tank, and going over the hills at the campground after we filled it, the water kept dumping out until we got it parked and level. Ran out of water on our second night since it was nowhere near full. Now that I have run a vent line up to the vent next to the filler, it can fill all the way and it doesn't spill out as it tilts while I'm moving it.