water tanks not filling

dedmiston wrote:

bp85257 wrote:
i found the vent tube, ran some water down it, some wire and pulled out some dirt, thinking a wasp(yellow jacket) made a mud nest,had same problem with propane on frig.( built mud nest over tube) then started filling, and short time later dirty water shot out and tanks filled 100%......yeah!
thanks for everyone's input.

Good for you. That's a weird one. I'm glad you figured it out.

I had this happen...it will happen again. I finally stopped it by putting a screen across the vent tube. Several manufacturers build in screens, but I had to cut down a hose screen to fit the vent tube and silicone it in place.

My symptom was annoyingly slow filling and burping/backflow from the fill port.

bp85257 wrote:
i found the vent tube, ran some water down it, some wire and pulled out some dirt, thinking a wasp(yellow jacket) made a mud nest,had same problem with propane on frig.( built mud nest over tube) then started filling, and short time later dirty water shot out and tanks filled 100%......yeah!
thanks for everyone's input.

Good for you. That's a weird one. I'm glad you figured it out.

i found the vent tube, ran some water down it, some wire and pulled out some dirt, thinking a wasp(yellow jacket) made a mud nest,had same problem with propane on frig.( built mud nest over tube) then started filling, and short time later dirty water shot out and tanks filled 100%......yeah!
thanks for everyone's input.

Maybe try this water meter https://www.homedepot.com/p/Orbit-Water-Flow-Meter-52212/205489792

Or try using an air hose and blow in the vent tube when you take is empty.

If there's a venting problem try filling slowly as much as you can, then let it sit, the tanks WILL equalize, vent or no vent so long as the balance pipe is lower than the water level (I'm sure it is). Then try to fill again. If it takes more water then I'd bet the slave tank is not vented. Good practice would be to vent them both, either via interconnecting the tanks at the top or to tie them both together in the vent line.

When you'r filling can you feel air being pushed out the vent or the fill tube?

I use a simple gauge on the fill hose, so I know how many gallons are going in.

my thoughts exactly old-biscuit.....thx

All tanks be they fresh or waste tanks HAVE to be vented so liquids can go in and come out.

If vent is not installed (or blocked) air can NOT be displaced as liquid flows in and allow air to be drawn back in as the liquid is removed otherwise tank will get pressurized or have a vacuum pulled on it


Install a vent on that second tank and your slow filling/lack of filling issue will be corrected

1/2" vent is more then enough

Which toy hauler brand and model do you have?

Does your TH have a "One Place" monitor panel? If so, it just may need resetting. They will adjust themselves to whatever sensors are there but you have to initiate the process. Usually the mfgs just mount them without doing the reset.
http://www.precisioncircuitsinc.com/wp-content/uploads/2014/08/One-Place-Trouble-Shooting.pdf