How to unscrew toilet water supply hose that is stuck to bottom of tank?

March 21, 2019 10:22 AM

I'm trying to install a bidet attachment to my toilet. I have the bidet attached to the bottom of the toilet seat, and now I need to remove the water supply hose from the bottom of the tank to install a T-adapter. I can unscrew the hose for a couple of turns and then it just... stops. I have tried unscrewing it with my bare hands, hands wrapped in a towel, and using a wrench but it won't budge. Any ideas? More info inside.

The part I'm talking about is the big white plastic piece on the right hand side of this photo. It seems like I should just be able to unscrew it completely but at a certain point it won't go any further. Is there something else I need to do, like remove something inside the tank that it could be connected to? Could there be some gunk built up on the threads inside and if so, how do I remove that? I am not very toilet savvy, so apologies for not knowing what this thing is even called, but my friends insisted this would be easy to install and I am feeling stooopid.

Help please! I want my bidet!

posted by joan_holloway to Home & Garden (19 answers total)

I'm wondering if the whole assembly isn't rotating when you turn the external nut until it hits a certain point INSIDE THE TANK and then stops. I'd verify that first. Should be easy if you can look inside the tank while you're turning. If so then fix accordingly by holding the interior piece.

Secondary to that, more force could be an option but always comes with it's own dangers. I don't know how strong you are or how long of a wrench you had but using another wrench or a cheater pipe is an option to get past the point of stoppage. Breaking things wouldn't be fun but, well, you need to get the job done anyway. If it's just cross threaded and you're being overly hesitant then, well, this solves that problem. Be sure to replace the fitting in question if it's damaged by said cross threading, don't try to reuse it.

Third option, which honestly shouldn't be necessary is cutting off the plastic/white connector you're talking about with a dremel or hacksaw or file or something. That'd take it off and you could survey the damage from there. Hopefully the stud/threads on the remaining piece aren't damaged in the process nor otherwise corroded and you're good to go from there.
posted by RolandOfEld at 10:35 AM on March 21, 2019 [2 favorites]

Try wrapping the whole assembly in a wet rag that has had boiling water poured over it, while wearing gloves, and turn it after a few seconds when the plastic has had time to heat up and perhaps soften a little.

Try tapping the plastic bit with a mallet or hammer on the side gently, in case you can crack gunk inside that is making it stick.

Try locking pliers instead of a wrench in case the wrench is not a good enough fit.
posted by Jane the Brown at 10:49 AM on March 21, 2019

Good advice above on how to remove the thing. Two other points just in case: the bidet installation instructions presumably told you to close the valve on the wall, so double-check that. If you're not sure, consider shutting off your main water valve. While you're working, keep a bucket that would fit under the tank nearby.

I like the loosen-by-applying heat idea, but I'd just point a hair dryer at it as long as everything's generally dry and you have a safe dry place to put the hair dryer down. Less messy.
posted by asperity at 10:54 AM on March 21, 2019 [1 favorite]

Hair dryer would work for that attempt but you'd have to exercise a bit more care lest you have one side of the plastic nut get melty before the otherside/inside was even warm.
posted by RolandOfEld at 11:11 AM on March 21, 2019 [1 favorite]

Best answer: This is almost always caused by the toilet assembly rotating around. I've occasionally had to get in there with a channel locks or vice-grips and grasp the base of the assembly from inside the tank to unscrew the hose fitting. This is easier with another person.

I've never had to use heat on this kind of plastic hose fitting; I'd be a little leery of doing so.
posted by aspersioncast at 11:16 AM on March 21, 2019 [1 favorite]

You say it won't budge. That means it's not spinning, correct?

Just to cover all bases, are you rotating it the correct direction? Lefty=Loosey but looking down on it from above, that's reversed.
posted by humboldt32 at 11:35 AM on March 21, 2019 [4 favorites]

Isn't there another nut flush with the toilet tank?

There is on my old one, and if there is on yours you need to hold that nut in place with a wrench and then unscrew the white plastic thing. The way you're doing it, you might be rotating the fitting as a whole with respect to the tank, which could break the seal with the tank and cause a leak -- plus you might be twisting the bumpy tube that feeds the water in, which could cause all kinds of trouble.
posted by jamjam at 12:18 PM on March 21, 2019 [1 favorite]

Best answer: In fact, I'd guess the reason it turns a bit and then stops is that the valve assembly inside the tank is turning, and the whole thing stops when that assembly comes up against the side of the tank.
posted by jamjam at 12:25 PM on March 21, 2019 [2 favorites]

Best answer: Millionth-ing rotating the whole thing.

Make sure the water is off. Flush the toilet to get the water out of the tank. Then take off the lid, reach down, and hold the base of the fill column while turning the nut on the outside with your other hand.
posted by notsnot at 1:53 PM on March 21, 2019 [1 favorite]

Response by poster: Thanks everyone. Yes, the water is off, I emptied the tank, and I am turning it in the correct direction. It turns maybe 3-5 full rotations before it gets stuck. If it is the toilet assembly, am I interpreting correctly that I need to essentially hold the assembly in place while rotating the hose thingy?

I will mark favorites after I give these suggestions a try tonight!
posted by joan_holloway at 2:06 PM on March 21, 2019 [1 favorite]

Best answer: No, you need to make sure the stud-and-attached-inside-the-tank-itself-assembly isn't rotating with the white plastic thing when you turn said white plastic thing. The braided hose thingy has no part in any of this.
posted by RolandOfEld at 2:15 PM on March 21, 2019 [1 favorite]

Have you tried unscrewsing the small end of that hose from the supply valve? Those hose fittings are supposed to turn around the hose freely but can get a bit stuck to the hose part if it's been sitting there for decades.

Then it's a good grip with the wrench and a tap tap on the other end to maybe get past whatever is keeping from turning. If that doesn't loosen it up... dunno.
posted by zengargoyle at 3:25 PM on March 21, 2019

I'm sorta wondering if the threaded pipe bit is screwed into the assembly and say flanged out on the inside and the pipe is actually turning through the nut and the assembly until it hits that point where it can't screw out any further. But I've never looked into how the inner bits are actually built assembly-wise.
posted by zengargoyle at 3:28 PM on March 21, 2019

Response by poster: Well, a little update. I just tried holding the assembly and the piece still won't unscrew. I swear it feels like it's glued on there. I'll try the suggestion of heating up the plastic a little but am not feeling optimistic :-/
posted by joan_holloway at 4:48 PM on March 21, 2019

Question - does the hose feel "loose" or still connected when you have unscrewed the white plastic nut - not as far as possible, say at least a few turns. I'm wondering if the end of the tube - the black rubber gasket in the photo you linked, is somehow stuck on the end of the fill valve - the tall part inside the tank it screws to, and the white plastic nut is being stopped by a larger part of hose fitting behind it.
The hose should feel loose when the nut is loosened. If not, try moving it around to break any seal between it and the bottom of the fill valve.
posted by rudd135 at 5:00 PM on March 21, 2019

After about 8 tries I would just crush the plastic connector (channel locks, vice grips, pliers) to get it off, and replace the hose with a fresh one that works properly.
posted by rhizome at 6:52 PM on March 21, 2019

How old is your toilet? Is it some sort of fancy dual flush unit or just a standard toilet?

If it has the old style arm with a ball on the end or new style flush valve like this Fluidmaster then replacement of the part the hose attaches too is straight forward and pretty cheap even if you do damage the end getting the hose off. (the fluidmaster linked works with most standard toilets.)

So taking rhizome's approach would be what I would do. Be aware that channel locks have a directional consideration to use; one way will tighten the pliers harder as you apply more force. Same with pipe wrenches.

If forcing the nut didn't work I'd attack it with a dremel.
posted by Mitheral at 7:55 PM on March 21, 2019

Response by poster: Thank you everyone! All of these answers are great but I chose the ones related to the assembly rotating as best. That was one of the factors involved, but also the plastic thingy was really stuck on super-tight. I asked for help from a neighbor who was able to loosen it with a much larger wrench than I had, which added the right amount of torque. Bidet is ready for business!
posted by joan_holloway at 8:31 PM on March 21, 2019 [3 favorites]

loosen it with a much larger wrench

I was about to suggest you go all Archimedes on it. Glad to see you've already got there.

In general, if you're already giving serious consideration to deliberately breaking a fitting there's very little to be lost by trying Ultimate Leverage Force first. If you don't have a bigger wrench you can often get good results by slipping a bit of pipe over the handle of the one you have, though this does risk breaking the wrench as well as the fitting.

Mantra for anybody dealing with recalcitrant pipe fittings: Plumbers are not subtle people.
posted by flabdablet at 11:11 PM on March 21, 2019