My 54 gallon water tank won't fill up. When it get to about 1/3 level, the water spills back out the inlet. Any ideas why this would happen? The lights on the monitor are correct, we run out of water real quickly, thanks for any help you can offer.

Water tanks have small vent tube which when kicked or clogged will prevent tank from filling - worth a look.

Look for a vent. On my trailer it is under next to the drain. It also has a valve on it that i discovered by accident for exactly the same reason.

You have a vent hose that should be next to the fill spout. Somewhere that hose is kinked, or you have something stored next to it pinching it off. Try blowing back through it when you find the opening, and see if it is open. Some will get water in them when you are filling, and that will block it. I used a piece of IV tubing to pass down the line a ways to blow it out. Just some things to check.Mike

I once found that mud-daubers had plugged my vent and caused the same effect.

Did this just start happening, or have you had the problem since new. If since new I'd be inclined to think that the tank is siphoning itself. If the vent line isn't routed above the high point of the tank and looped or "shepherd hooked", you'll experience siphoning.

Fresh Water Tank Won't Fill | Good Sam Community

mark5w
Explorer
May 02, 2013
Neighbor had same problem. His anti siphon valve on the fill was bad. Dealer installed a new one: no problems. Check for this problem.
laknox
Nomad
May 01, 2013
YC 1 wrote:
My last rv fill hose was to long and crimped. It was a pain but cutting it to proper length solved the issue.

Do you have two fill options? For example a gravity feed where you hold the hose and the other would be an actual connection to the hose. If gravity filling the tank and the vent is blocked you should get a big burp from it when removing the hose.

x2 on the "burp". Even with my vent working properly, if I fill too fast, I'll get a bath if I pull the hose out before it stabilizes pressure after shutting off the water.

Lyle
eHoefler
Explorer II
May 01, 2013
A low spot in either the vent line or fill line can have water pooling in it and causing it not to vent. Check the lines and make sure they both slope downwards toward the tank and not collecting water. Sometimes just shortening them or adding a support or two is all that is needed.
lee_worsdell
Explorer
May 01, 2013
my vent was full of bugs and thing I had never seen before. blew it out with air
Goostoff
Explorer
May 01, 2013
Kenc_AL wrote:
homedad wrote:
I once found that mud-daubers had plugged my vent and caused the same effect.

X2

X3 My in-laws were having trouble last year till I went over to help and found the vent plugged from mud daubers. Them little bastids can make a mess out of a lot of little holes.
Kenc_AL
Explorer
May 01, 2013
homedad wrote:
I once found that mud-daubers had plugged my vent and caused the same effect.

X2
SuperDutyMan
Explorer
May 01, 2013
Mine will do that once in awhile,I just wrap my hand around the hose and the fill opening and try to seal it,in about 10 seconds,the vent will burb some air,I let go and it fills the rest of the way with no problem,it just gets a air pocket in it.
Sooner_Schooner
Explorer
Apr 30, 2013
spindrift wrote:
Did this just start happening, or have you had the problem since new. If since new I'd be inclined to think that the tank is siphoning itself. If the vent line isn't routed above the high point of the tank and looped or "shepherd hooked", you'll experience siphoning.

This is a new problem, just got to a park where we have to fill tanks, there are no direct hookups. We were here last fall with no problems then.
YC_1
Nomad
Apr 30, 2013
My last rv fill hose was to long and crimped. It was a pain but cutting it to proper length solved the issue.

Do you have two fill options? For example a gravity feed where you hold the hose and the other would be an actual connection to the hose. If gravity filling the tank and the vent is blocked you should get a big burp from it when removing the hose.
spindrift
Explorer
Apr 30, 2013
Did this just start happening, or have you had the problem since new. If since new I'd be inclined to think that the tank is siphoning itself. If the vent line isn't routed above the high point of the tank and looped or "shepherd hooked", you'll experience siphoning.