Toilet runs every 10 mins
#1
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Toilet runs every 10 mins
After replacing the hot water heater that failed and flooded bedroom closet that I was already in the process of replacing the laminate from the burst lav pipe a month ago, I turned my attention to my sister's master bath toilet. 
I have totally rebuilt this Mansfield 160 with new flush tower, new seal of course and used a FluidMaster 400 fill valve. New flange on floor to replace the cracked one. Problem is the toilet seems to run a few seconds about every 10 mins, between run times the unit is silent with no visible signs of any leakage taking place. The American Standard at my house does the same thing with same 400 fill valve. What am I missing?

I have totally rebuilt this Mansfield 160 with new flush tower, new seal of course and used a FluidMaster 400 fill valve. New flange on floor to replace the cracked one. Problem is the toilet seems to run a few seconds about every 10 mins, between run times the unit is silent with no visible signs of any leakage taking place. The American Standard at my house does the same thing with same 400 fill valve. What am I missing?
#3
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To test the flapper put some red food coloring in the tank, if it shows up in the bowl it's leaking.
100% sure the plastic tube from the flush valve is mounted to the clip and is sitting just above the over flow tube and not down inside it or just laying in the tank?
100% sure the plastic tube from the flush valve is mounted to the clip and is sitting just above the over flow tube and not down inside it or just laying in the tank?
#4
If it's not the *flapper* sealing properly it could also be too high of a water level in the tank. This would cause the tank water to spill into the overflow/fill tube -- lowering the water level thus opening the fill valve and so on repeatedly.
Check the water level to ensure the fill valve shutoff is adjusted to be at the water level mark in the tank or about an inch below the overflow/fill tube.
Check the water level to ensure the fill valve shutoff is adjusted to be at the water level mark in the tank or about an inch below the overflow/fill tube.
#5
Make sure the rubber fill tube off the fluidmaster valve is affixed to the fill tube with the clip provided and that the tube is not just shoved down the tube. Shoving it down the tube will cause a siphon to result after flush that slowly pulls water from the tank. When the level drops enough, the fluidmaster replenishes.
#7
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Thanks for all the replies guys. Yes, the water levels in both tanks are set at about 1 inch lower than fill tube, the fill hoses are not under water where they could siphon, and the Mansfield flush tower is all new seal and plastic, the tank is silent in between times it runs.
On the Mansfield, I initially thought that a new seal on the flush valve would fix things, its 14 yrs old and has never been touched. Wrong! The new seal made the leak worse,lol! The old seal was pretty bad off too, it was all wavy and disfigured, I don't see how it was sealing at all! So anyway I ended up replacing the entire flush valve unit , then discovered the fill valve was pretty much rusted/crudded shut, new tank to bowl gasket, found the tank loose on floor, tightening bolts didn't help....yup, flange broken!
On the Mansfield, I initially thought that a new seal on the flush valve would fix things, its 14 yrs old and has never been touched. Wrong! The new seal made the leak worse,lol! The old seal was pretty bad off too, it was all wavy and disfigured, I don't see how it was sealing at all! So anyway I ended up replacing the entire flush valve unit , then discovered the fill valve was pretty much rusted/crudded shut, new tank to bowl gasket, found the tank loose on floor, tightening bolts didn't help....yup, flange broken!
#8
You have eliminated most of the usual suspects. In the past year I've had two Am Std's with the same problem, except the leak was much slower and harder to find. A dye test showed nothing, but shutting off the water supply for hours showed the water was going somewhere. I took the tanks back off and set them on the bath lav and filled with water. One had a minute leak past the flapper and the other required putty around the the flush/overflow tower in addition to the gasket. In the midst of this I talked with Fluidmaster tech support and was told that those fill valves, when new, are ultra sensitive to small water losses. Hope there is a pearl of wisdom in here somewhere.
#9
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Thread Starter
Thanks all for reminding me of the dye test, I'll try that next time I'm over at my sister's place.
The leak is so slight, especially on mine, think I'll wait on doing anything else at this point. If anything, I might lightly "dress" the seal surfaces with some sand paper or something?
The leak is so slight, especially on mine, think I'll wait on doing anything else at this point. If anything, I might lightly "dress" the seal surfaces with some sand paper or something?