Mystery flood after rain

[dancewithmarg]

Wife (me) at home posting for DH who has just gone to trailer park to check on RV after heavy rain. Says the toilet has fllled up and overflowed onto bathroom floor.. Second time it's happened after rain. Water connection had been turned off and hose drained as usual last time we left. Water tank was emptied after first flood. Anyone had this happen, or any suggestions as to why?

[Phdruss]

Roof vent for plumbing?? Is the black tank filling and overflowing??

[JRTJH]

Two quick possibilities come to mind. First, if the water overflowing onto the bathroom floor is clean, clear water, I'd suspect a leaking toilet flush valve.

If the water overflowing is "black tank contents" then I'd suspect that rainwater is getting into the black tank, possibly from a missing vent stack cap on the roof??? But even if it is, it shouldn't be able to flow up into the toilet if the toilet flush ball is sealing properly.

So, it sounds like either you have a defective, leaking foot pedal water valve or you have a combination of several problems: Leaking black tank that overfills when it rains and leaks up, into the toilet through a defective, leaking bowl seal.

A third, unlikely problem is the foam seal where the toilet sits on the tank fitting. It's a "wax ring" in home toilets and a "foam ring" in RV applications. If it's leaking, the water from the black tank could be seeping out around the base of the toilet, but that's not what you say your wife described. ???????

[sourdough]

Hopefully your DH can analyze this a little closer.

As was mentioned, the problems you describe are pretty hard to assess if you have both the city water turned off and the FW tank drained. All that fresh water "inside the toilet" has to come from somewhere and the toilet bowl is sealed, or should be, from any water source per your description so that is difficult to figure out. Is there a roof vent above the toilet?

Edit: DH not DW! Sorry.

[notanlines]

Taking everything into account that has been said so far, let's say the vent cap has deteriorated and the vent is a 2 1/2 inch pipe. It would take about 2000 inches of rain to fill a 50 gallon black tank.....so much for that.
The RV park water was turned off at the pedestal. Maybe, just maybe the water cut-off leaks just the tiniest bit. And while we're making up strange things, your shut-off on the toilet foot pedal leaks just the tiniest bit. Strange,, but could happen.....I sure would like to know what it turns out to be.

[AbHDToyHauler]

Maybe it's just a coincidence that its raining. Sounds like leaky toilet fill valve if the toilet is actually full ? If so , figure out how long since you last checked on/were at trailer and then go there again in half as much time and check toilet level or sooner if that makes more sense.

[Ken / Claudia]

A guess I have IF the pump was left on and IF there was water left in the fresh tank or city water still coming in and the toilet valve is open/broke, yeah that would fill the toilet. But, if there is NO water in the system and the toilet lid is left in the closed position, how the heck would it fill. Does not make much sense but, strange things do happen.

[Harleydodge]

Only other guess I would have would be the ceiling vent/fan leaking (or left open) and dripping into the toilet, hence overflowing?

[14george]

This could be happening are you leaving your black tank dump valve open could b3 backing up from sewer

[sourdough]

Maybe the OP will post back to fill us in. She said it had been raining a lot - "flood". The FW tank was drained after the last rain event. City water off and hose drained...I assume removed. Checking and mentioning those things leads one to believe it is overflowing with fresh water, which in the circumstances above, would be nigh unto impossible. Enter....a leaking vent above the toilet??? I think they would be closed. Now, in heavy rains bordering on "flood" it would be possible for the sewer to back up given the right circumstances...but that's not mentioned. Oh well.....another unsolved mystery.....:confused:

[dancewithmarg]

It's fresh water that filled the toilet. Will let you know if we solve the mystery. DH will be checking for the next few days. Thank you for all suggestions.

[hankaye]

Howdy All;

Dang I love a locked room murder type mystery :cool:.

Being fulltime I've noticed that the overhead vents don't need to be opened
very far for rain to "bounce" into the RV while it's raining. Something to consider.

hankaye

[mhbell]

Taking everything into account that has been said so far, let's say the vent cap has deteriorated and the vent is a 2 1/2 inch pipe. It would take about 2000 inches of rain to fill a 50 gallon black tank.....so much for that.
The RV park water was turned off at the pedestal. Maybe, just maybe the water cut-off leaks just the tiniest bit. And while we're making up strange things, your shut-off on the toilet foot pedal leaks just the tiniest bit. Strange,, but could happen.....I sure would like to know what it turns out to be.
I think maybe you hit the nail on the head, if the op leaves the hose hooked up. The first thing I would do is unhook the hose. In many campgrounds the water valve does not turn all of the way off and over time pressure will build up in the hose especially in the hot sun. With a leaky toilet valve the toilet will fill. Had it happen to me. with a older trailer.
Mel

[dancewithmarg]

Notanlines, I think you found the answer. We've had the hose disconnected and have not had the problem since. Thank you everyone for your ideas and suggestions. Fingers crossed we'll not have the problem again, and we've had some pretty heavy rains since this happened, and didn't have any more floods.