Toto Aquia 2 piece toilet. Runs continuously

The toilet tank runs continuously in the bowl. I turned off the water supply and the leak stopped so I think that eliminates the flush valve. So I switched out the diaphragm with a new Korky cap R528. No improvement. So next I plan to replace the fill valve using the Korky 528mp from lowes. Is this the right valve for the Aquia 2 piece toilet? I read somewhere that the double flush models like Aquia might need a different model of fill valve. Thanks!



The Aquia use the Korky MP valve or use the repair kit for the cap.
To remove the tank, turn off the water supply, remove the supply line at the shutoff, rotate out the flush valve after unhooking the fill tube, use a screwdriver and remove the bolts that hold the tank to the bowl.

 

Okay. Stop. Let's diagnose.

If the problem is the fill valve (i.e. a runaway fill valve), the water level in the tank will get pretty high and the water will spill into the overflow of the flush valve. When you have the top off the toilet, do you see the fill valve continuing to run and water just flowing into the flush valve and then into the bowl?

You replaced the R528 cap and you still have the problem. So I'm thinking if indeed you have water overflowing into the flush valve, maybe your fill valve is just adjusted too high. You could lower the water level a bit by removing the little locking key at the back of the valve (if it's in there), turn off the water (because the pressure helps keep the fill valve locked in position at a particular height), push lightly down and twist to unlock, then lower the head of the valve, which would make the water level lower. If that's the problem, you're done.

However, I am thinking that perhaps you do have a slow leak past the gasket on the flush valve. Turning off the water may make it stop "running", but a slow leak could still be going into the bowl. The right way to do this is to mark the level that the water is at with a pencil, turn off the water at the wall and leave it overnight. If the water level drops, you have a flush valve leak, and most likely just need to replace the gasket. Let us know if you have the one piece or the two piece Aquia (or tell us the model number), and we can help you with the part number. There are lots of places online to get the gasket for just a few bucks, or it may be available locally.

The 528MP will fit; it's basically the valve you have there. Someone at Korky once told me that the ones they were making for the Aquias have the ability to go a little taller than the 528MP, but it's unclear whether that's necessary or even accurate. I think Terry just uses the 528MP (actually now the 528PRO, which is a version of the same thing) for all the Totos. The TSU99A.X, which is basically a 528MP with a Toto decal on it for most purposes, does fit for sure. Korky also sells the TSU99A.X under its own brand name as the 528GT (NOT the 528T, which is different). Oddly, places online sell the Korky-branded one for like $3 more than they sell the TSU99A.X, so I would go with the former. However, you save about $6 buying the 528MP, which will do everything most people need, so that would be my first choice if you need it.

Candidly, odds are it's a slow leak past the flush valve, because that's what it usually is, but try my recommendations and see.

 

Thanks for your detailed answer. I have another toto aquia(2 piece) in the home that works fine and I swapped the flush valves to see if that was the problem. This did not fix the problem so I think that eliminates the flush valve as the problem. I do not see water flowing out of the fIll valve but there is a hissing sound at the fill valve and I think it is probably leaking somehow. So I probably will replace the fill valve with Korky 528mp. I am not looking forward to taking off the tank as there is no room for my hands to work in the tiny space under the tank to unscrew the bolt. I have learnt a great deal about how toilet tanks work, so that is some consolation

 

Dito. You got the right guy before I read your issue

 

I just went through the same issue with a Toto Aquia II two-piece toilet running intermittently. At first I thought that the problem was in the flush valve, so I changed the gasket, but that did nothing. Then I noted that this only happens when the water supply is on, so I suspected the fill valve. Unfortunately, I couldn't figure out how to remove the fill valve without taking the toilet off (no access up against BR wall), so I experimented with cleaning out the old valve per some of the instructions above and in other posts. On some fills there would be no leaks, but eventually the water would run again if I left the supply valve open.

I finally got tired of messing with it, took the toilet off (happy to see there was a rubber gasket instead of a wax ring) and removed the old valve. Even with the toilet in the middle of the bathroom it was a pain to get the supply hose and fill valve nut off--I guess that's why plumbers make the big bucks. I used a 1-5/32 shower valve socket to get the old nut off. Replaced with the Korky Universal Fit Adjustable (QuietFill) toilet fill valve from Lowe's (I think it was the 528PK, <$10). Adjusted/locked in the water level height to match the old valve. The new valve came with a semi-knurled nut, but that was very difficult to tighten by hand in the restricted space under the toilet, so I ended up using the old hex nut (plastic) and tightening with the shower valve socket.

Since it was such a pain to service in place, I decided to replace the steel-braided supply line as well--maybe overkill, but I don't want to mess with this again soon. Re-set the toilet, and problem solved. I would not buy this toilet again, because there is no reason (other than a false sense of aesthetics) that access to the fill valve should be so difficult, but it is working fine again.

Hope this helps others with a similar problem.

 

Was that 1-5/32 shower valve socket a pretty loose fit? I had measured the nut on my Toto Vespin II at about 1-1/8 inch, but I did not see a comment that that matched what others found or not.

 

Don't remember it being real loose; at least there was no noticeable slippage. The 1-5/32 was the closest match I found in the socket set I had. I was able to remove and re-install with no issues.

 

The proper (and easiest) way to change the fill valve on the two-piece Aquia is to pull the tank. If you read the installation instructions, they say to route the flexible hose through the base and attach it to the tank before installing the tank. They also say that to replace the fill valve, pull the tank, THEN remove the hose from the fill valve, replace the fill valve, reattach the hose, then reinstall the tank. Pulling the whole toilet doesn't make accessing the fill valve any easier. It's the tank you need to pull.

One other thought: I'm not sure which 528 you bought, in part because some of the stores add suffixes to the end of the model number that aren't the official ones. The cap color is a good clue, though. The Korky valve you want for this toilet is the 528MP (Quietfill MaxPerformance Fill Valve), the one with the silver cap and little refill-adjuster thingy, not the plain ol' 528 with the white cap. The white-cap one may not give you enough refill water for the bowl. However, if you're comfortable with how full the bowl is when the water shuts off, then swell. No harm, no foul. If you're finding that it doesn't refill the bowl enough, you can replace it with the silver-cap one, which gives double the refill of the white-cap one when the little adjuster is fully-open, and adjusts downwards from there.

Manual: http://assets.totousa.com/product-files/0GU031_DUAL_FLUSH_TOILET_IM.pdf

 

This applies to most toilets in general.

It is rather easy to inspect the flush valve. You're looking for wear grooves on the flap, vulcanization where the flap sits over the outlet, and other signs of warping or things bent.

Chemical wear is the #1 enemy of these. If you are using chemicals, some manufacturers recommend changing the flap once every 6 months. That's right.

Next, fill valves all pretty much work the same, a rubber disc diaphram that sits on spout, like a saucer covering a tea cup. The fill valve rubber disc diaphram gets a lot of pressure from the float to seat the water spout shut, and gets a wear groove on that over time, also if it hardens up, that too will fail.

If you look at the fill valve seal replacement repair kit for your model, you will see what it comes with, and what the exact wear and tear parts are.

This one is rather easy to DIY, and if you screw it up the fill valve assembly, you can always replace the entire fill valve, which is what most folks do. Most folks are completely unaware that fill valve repair kits are even available.

 

I am a bit shocked that that is the normal way.

It sounds maybe easier to pull the toilet if you are strong, considering that there is no wax ring to deal with.

 

Yeah but on this toilet, even if you pull the whole toilet, there is no easy way to get at the nut on the outside of the tank at the base of the fill valve until you remove the tank. As this poster found out. Once you pull the tank, it's easy. That's why the instructions say to route the flexible hose through the base and attach it to the fill valve before you mount the tank.



The tank is held on with the two bolts shown at the bottom of the tank.

 

Thanks wjcandee, appreciate the response. I was not sure how easy it would be to pull the tank with the toilet in place. I didn't have/couldn't find the install manual; the copy you linked to will come in handy next time.

I will say that pulling the whole toilet did make it a bit easier to access the fill valve, which I was able to get off (with the shower valve socket) because it had a hex nut. I don't think it would have been possible if I had to do it by hand, which is why I re-used the hex nut to reinstall. Live and learn.

The valve I bought was a MaxPerformance QuietFill valve with a silver top and adjustable refill "thingy." I will say that the new valve is definitely quieter than the original part (not that the original was really noisy). Toilet continues to work fine after the fill valve replacement.

 

Many skirted toilets make it hard to do repairs unless you know the tricks. Some are a pain even if you do (IMHO, Kohler is one of those).

 

Many skirted toilets make it hard to do repairs unless you know the tricks. Some are a pain even if you do (IMHO, Kohler is one of those).

 

Glad to hear that it all worked out! Happy to help.