how often do float valves fail


New member
Thinking about using a larger top off reservoir in my house that I won't be able to pick up & move around like I used to--used to fill it up outside. Anyway, this all depends on how safe/reliable float valves are in shutting off the rodi/hose unit. Anyone recommend any in particular? Is this a plan destined to have wet floors one day? Thanks.
Anything can fail.

I've used my Kent RO/DI float switch for several years now with no failure.
No offense thats a bad are looking at it all wrong. If it happens once that is too many...bam your tank is dead. So how often isn't really the prudent question.

Look into topping off via dripping it 24/7....use a peristalic pump.
I use a Tunze osmolator to top off my tank which is redundant. I'm just considering a float on the reservoir which if overflow occurs it means a wet tile floor initially, possibly some wood floors soon there after which would not be good. The Kent float kit is what I was considering, just looking for more feedback on it or other floats.
I "make" water into a brute container but it isn't tied in with the tank. I have a kent valve as a backup in case I forget to turn the water off but I do not trust it. My unit makes ~ 3 gallons an hour so I know to turn it off after a certain amount of time.

Eventually I plan on putting a redundant system on that, probably a timer on a solenoid or an extra drain to the sink that way I can trust it.
Float valves WILL fail, sooner or later. I have mine set up to fill automatically, BUT, I only do that about once every 5 days. Once the container is full, I turn of the RO unit. That way, the WORST thing that can happen is I dilute my tank by 35 gallons in 300 gallons - not enough to kill everything. Um, that and about 15 gallons on the floor! I also have water detection alarms.

Additional reduncancy can be put in with a solenoid valve AND a float valve.
I've used the Kent marine float valves in my sump for auto topoff for 4 yrs with no problems. if for any reason the float valve would fail the system would only get an additional 5 g of top off water. i fill the top of bucket every couple days. i have heard stories of snails getting in the float valve and preventing it from closing but if u use a bracket extending out where the snails can never get on the float the chances are reduced.
Barjam & Bstreep that's kinda what I do now, I know about how long it takes to fill up my 12 gallon reservoir but I don't have a float valve cuz I do it outside. Make water once/week for water change & top-off. Then I lug it back inside about 12 feet. I'll be getting a system of about 140 gall total in couple months so I'll need a bigger reservoir-- one I can't move around. So was thinking about drilling a hole in the door to shoot the ro/di tube through from my hose & unit inside to the reservoir. Stupid question-- what's difference between solenoid valve & float valve? Is float just mechanical & solenoid electric on a timer? How do you set up a solenoid?
Reefbox, I like the 5 gall "mini-reservoir" idea. Either keep a larger reservoir next to it if I can hide it or maybe put that outside. Just tested my osmolator's high water alarm/shut-off-- first time since I set it up 3 years ago (what a moron) & it worked perfectly so that's good. But u guys are right, devices will fail eventually. So I like the mini-reservoir idea. Have to fill it every couple days I guess. Reefbox, do u run a chiller, any idea on how much evap u get per day or week? I'll be getting a 125 w/15 in sump, 2 250de & fans no chiller.
I change mine every six months or so. No problems now
In the past ran one for 3.5 years w/o issues.
I'm planning on upgrading my 5 g bucket to a 10 g container soon. At the very worst I would only allow 10 g into the system. I would never hookup an auto ro/di topof to a system. reward vs the risk is not there for me and i've heard to many tragedies resulting from level controller device failures.

i ran my ro/di water line to my 5g bucket and added a valve.

I do not use a chiller. I run a fan/ac and it stays at 80 deg. f. but im in a much cooler climate. pittsburgh

I would say i get .5-2 gal evap. per day, depending on what time of the year. but i use evaporative cooling for my reef with a fan pointed into the sump, which creates evaporation. I only have to run the fan in june, july and august.
Stuck in the up-- up stops the flow I'm guessing? Better than the opposite I guess:) Change float valves every 6 mos Gasman?
I've been using the same float valve for 4 yrs.

Whenever it does fail that will be 10 g in a 125 and my sump can handle the extra volume. No big deal. It takes awhile to drain 10g w 1/4" airline hose and i think most inhabitants will survive the acclimation.
Sounds good Reefbox, thanks for the evap info & I agree with the 10 gall size. Think I'll follow your plan. Thanks.
<a href=showthread.php?s=&postid=10455665#post10455665 target=_blank>Originally posted</a> by upsetter
Stuck in the up-- up stops the flow I'm guessing? Better than the opposite I guess:) Change float valves every 6 mos Gasman?

Yes, It stopped topping off water when I was gone for a weekend. Came home to return pump blowing air. All was fine, Thank God!:)