Humidifier Float Valve

[superduperwesman]

Bought one of these last night b/c I'd like to start mixing my water in advance. That way I can do a few water changes before having to mix some up again. I can give it lots of time to get up to temp and I can go watch TV while I let a few weeks of water accumulate from the R/O system (once I go pick it up from my old place and install it ahah)

But so far it seems to work great and the price was even better (around $8). Anyone ever have a bad experience with one?

[banditpowdercoat]

You just put it on the RO line? Did you add in the Shutoff valving for the RO unit Inlet? Can't just put a float on the RO outlet because the inlet will still have water pressure and you will be just pushing water out the waste line.

If you turn off the inlet water when it comes full, then that is OK, but as long as you know, without a float shutoff valve, whenever water is supplied to the RO unit, Waste IS being made, regardless if RO is being made or not

[BWI]

just dont trust it 100%... their good for this application but don't leave the house when its in use.


yea i agree with the post above.. do you have a Auto shut off on the RO unit?

[banditpowdercoat]

I have a Kent Float valve mounted 3/4 up in a Rubbermade garbage can. Almost a year now, Never had an issue. We'll turn the RO on when the can is low and leave it for 1-2 days. I don;t think you will have a problem with the Fresh water. How many humidifiers have you heard about flooding? replace the float valve every couple-5 years just to be safe, because the seal will wear out, just like the taps in your home.

Now, using it direct in a sump, possible Salt Creep and such, That's a different story.

[superduperwesman]

You just put it on the RO line? Did you add in the Shutoff valving for the RO unit Inlet? Can't just put a float on the RO outlet because the inlet will still have water pressure and you will be just pushing water out the waste line.

I'm confused? Assuming I had no float valve and I was just using the R/O for drinking water... so what happens at the R/O tap on my sink? Am I suppose to shut of the inlet to the R/O system every time I'm not filling a glass of water?

If you turn off the inlet water when it comes full, then that is OK, but as long as you know, without a float shutoff valve, whenever water is supplied to the RO unit, Waste IS being made, regardless if RO is being made or not

I have a shut off on the line that I t-ed to the mixing tank just as an extra precaution for the twoish weeks that I'm not making water but again I fail to see how the float switch doesn't simulate pretty standard operation?

[superduperwesman]

just dont trust it 100%... their good for this application but don't leave the house when its in use.


yea i agree with the post above.. do you have a Auto shut off on the RO unit?

Yeah, I won't 100% trust in which is why I have the valve as an extra precaution.

But again, I'm not really understanding the RO Auto shut-off?

Once the little R/O pressure tank fills doesn't the unit always shut off?

[superduperwesman]

Oh ok I think I under stand the confusion. I didn't just add it straight to the R/O outlet... I t-ed it into the regular supply line (after the pressure tank)

[banditpowdercoat]

Yeah, I won't 100% trust in which is why I have the valve as an extra precaution.

But again, I'm not really understanding the RO Auto shut-off?

Once the little R/O pressure tank fills doesn't the unit always shut off?

Ohh you have a RO unit with the pressure tank, then you should allready have a shut off valve. basic RO/DI units like most reefers have do not have the shutoff incorporated as they do not have a pressure tank.

This is what I am refering to
http://ebay.f3images.com/IMD/feeds/KM1651_50.jpg

[sphelps]

Your RO has an auto shut off, just ignore that post. It doesn't make sense to me either.

[sphelps]

I wouldn't trust my float 100% either, I put a ball valve before the float so I'm only filling the container when needed. The float itself is more of a safety switch so I don't flood the place if I forget to turn off the valve.

[banditpowdercoat]

Your RO has an auto shut off, just ignore that post. It doesn't make sense to me either.

what does not make sence? I think I'm being clear? I made last post before I seen his last ones

But yes, now that he says he has a Pressure tank RO, he allready has a shutoff installed on the RO system.

[hillegom]

You do not have to have a tank in your RO system to have an auto shut off valve (ASOV)
Most systems come with this valve so that the unit shuts itself off and does not make any more ro water nor any more water to the drain.
Here is a link, for a picture, there are a lot of pics on the web.
http://www.goodwaterwarehouse.com/cat/6_roasv.shtml

[Delphinus]

I have a Kent Float valve mounted 3/4 up in a Rubbermade garbage can. Almost a year now, Never had an issue. We'll turn the RO on when the can is low and leave it for 1-2 days. I don;t think you will have a problem with the Fresh water. How many humidifiers have you heard about flooding? replace the float valve every couple-5 years just to be safe, because the seal will wear out, just like the taps in your home.

+1


Now, using it direct in a sump, possible Salt Creep and such, That's a different story.

FWIW I use them in my sumps .. don't really have a problem with salt creep because the freshwater coming out flushes any away. About once a year I'll take them apart and blow out any dust or whatnot.

Only thing is you do not want your RO/DI direct to a float valve, as it will cause excessive wear and ultimately premature failure of the RO membrane. Instead, feed the valve off a bucket reservoir that you only fill once empty.

That's what I do anyhow. :)

[superduperwesman]

Yeah I have 2 float valves wired to a sprinkler valve for my tank ATO. And I also have the sprinkler valve on a timer so it only has power for 2 min 6 times a day. So It has a fair amount of protection. If the first float fails then I have the second and if it fails too then hopefully full water for 12 min a day won't flood the tank before I notice.

The humidifier float is just for my water changing. Like sphelps said, just a safety mechanism in case I forget that I'm filling the can while watching tv or something. I assumed that they were pretty reliable if they're used in humidifiers but I wasn't sure if maybe humidifiers had another safety mechanism that I was unaware off? And I wasn't sure how often these need replaced / have problems but it doesn't sound like anyone has had any?

[superduperwesman]

You do not have to have a tank in your RO system to have an auto shut off valve (ASOV)
Most systems come with this valve so that the unit shuts itself off and does not make any more ro water nor any more water to the drain.
Here is a link, for a picture, there are a lot of pics on the web.
http://www.goodwaterwarehouse.com/cat/6_roasv.shtml

Oh ok... thanks. I'll look for this when I get home... like I said. I don't actually have it all plumbed in yet I was just trying the float valve out on the R/O supply line that I ran. I'm gonna pick up my R/O from my old place this weekend.

[viperfish]

I have a humidifier float valve installed in an 80 gallon Canadian Tire Rain Barrell. It works flawlessly. I get enough water to do changes in all of my tanks at once if I need to. I have no valve and the thing has not failed me in over a year. I do have an auto shut off on my RO/DI system. I currently have my RO/DI supplying water to my 180, 90, 33, 20, and w/c barrell all at once, and all with humidifier float valves. I just fill my w/c barrell at night so i can keep the other resivoirs full for my ATO's.

[Delphinus]

No extra protection on the humidifiers and if you think about it household pressure is anywhere from 50 to 100psi typically.. think the biggest problem tends to be calcium buildup over time.

[sphelps]

what does not make sence? I think I'm being clear? I made last post before I seen his last ones

Most of it, but don't take it personally. All RO units should have an auto shut off unless they are the portable units which are only hocked up to a water source when needed. I wouldn't say that's the norm most units are permanently hooked up to a water source and the shut off valve is on the output. This being the case it will require an auto shut off whether a pressure storage tank is used or not.

The basic rule is to never rely on mechanical floats. I believe humidifiers have a drain if the water level gets too high, same as a toilet. Electronic systems can be designed with unlimited safety systems to prevent failure so you actually design them to meet your own personal confidence level.

[viperfish]

The basic rule is to never rely on mechanical floats. I believe humidifiers have a drain if the water level gets too high, same as a toilet.

Most older humidifiers have a float valve and pan to hold water, the only drain is the one on the floor when it overflows. The mechanical float valves on these units last for years without fail. In my previous house the float valve had been working for 11 years and had not spilled a drop. The key to these things is simplicity. In my current humidifier I have an electronic solenoid and it took three of them before I got one that worked properly. I don't know of too many electronic devices, especially ones controlling water, that I would trust for 10+ years.

[banditpowdercoat]

Well, I have just seen more of the temp hookup style RO units in this hobby than the permanent, drinking water kind.

[Delphinus]

I still use on one of my sump's the first float valve I ever bought for a tank more than ten years ago. It's been in continuous use as an ATO in the last ten years without a single failure. Best $8 I ever spent in the hobby. I bet most $200 switch and pump style ATO's cannot claim that kind of uptime yet. Sometimes simplicity is just fine.

[whatcaneyedo]

I also have one on a brute trash can with a ball valve right before it. After a water change I let it fill up to the float valve and then turn off the ball valve as an extra precaution.

I have a friend in town who flooded his basement twice using one of these in much the same way. I dont know the full story about how it happened but I think he just had it mounted too loose or the float wasnt inserted correctly. Water on the floor sensors are always a good idea and check your installation to make sure it works before turning the water on and leaving for the day...

[banditpowdercoat]

I still use on one of my sump's the first float valve I ever bought for a tank more than ten years ago. It's been in continuous use as an ATO in the last ten years without a single failure. Best $8 I ever spent in the hobby. I bet most $200 switch and pump style ATO's cannot claim that kind of uptime yet. Sometimes simplicity is just fine.

I'm seriously thinking about this for my next sump. But I got 2 FW tanks I use the RO water for too. Maybe when I finally get rid of them? How did you mount? Did you drill through sump? I'd like to be able to add it after. Glass sump, don;t want to remove to add a hole

[mark]

living on the edge here.

I have a furnace humidifier float valve in my sump connected directly to my ro/di for a ATO for the last 4-5 years, zero problems.

What let's me sleep is there's many more furnaces out there than fish tanks and in all my years never come across it myself or heard from someone their basement flooded due the humidifier. I've had a problem once on a old furnace with the valve not opening from deposits. Figure here I'm running about 2g a day of ro/di through it, it's flushing itself.

Now would not use one on a kalk drip system.

http://i67.photobucket.com/albums/h316/das75/float.jpg

[superduperwesman]

living on the edge here.

I have a furnace humidifier float valve in my sump connected directly to my ro/di for a ATO for the last 4-5 years, zero problems.

What let's me sleep is there's many more furnaces out there than fish tanks and in all my years never come across it myself or heard from someone their basement flooded due the humidifier. I've had a problem once on a old furnace with the valve not opening from deposits. Figure here I'm running about 2g a day of ro/di through it, it's flushing itself.

Now would not use one on a kalk drip system.

http://i67.photobucket.com/albums/h316/das75/float.jpg

That's the one. Yeah i just drilled a hole in the can. So based on everyone's experience I think I'll be good :)

Glad I heard about this. Really great item

[Delphinus]

I'm seriously thinking about this for my next sump. But I got 2 FW tanks I use the RO water for too. Maybe when I finally get rid of them? How did you mount? Did you drill through sump? I'd like to be able to add it after. Glass sump, don;t want to remove to add a hole

Yeah, just a 1/2" hole through the glass and done. I'm liking Mark's slotted idea in the corner of the sump for adjustability though - probably pretty easy to set up with some acrylic and a router or worst case scenario some glass slats siliconed together (I don't have a router so just thinking out loud how I'd go about doing it myself..)

Mark, I don't know how you're not burning through RO membranes like that.. but hey, if it works, it works. I myself found out the hard way to use a reservoir first .. but we all know the laws of physics are totally different up there in E-town than down here so that must be it.

[sphelps]

Well I guess some of you guys enjoy living on the edge a little :lol:. Even with an old humidifier without an overflow drain, if failure occurs it still spills down close to a floor drain so no damage is done. Also keep in mind that a fish tanks isn't exactly the same as a humidifier. In the tank environment it's much more vulnerable since it isn't as clean and things can jam it up or stop it from closing.

Simplicity is better as a rule of thumb within reason (a car is still better than a horse) but mechanical floats do fail so I think it'd be pretty foolish to hook up one to an actual aquarium from an unlimited water source, if you've got a separate container for top off which wouldn't harm the tank if it was all introduced that's fine but a direct RO hook up is an accident waiting to happen. A solenoid and a timer can be easily setup for less than $100 which is very cheap insurance considering what has already been invested.

[Delphinus]

True dat Steve, the most sage outlook is to assume anything can fail - valve or switch or whatever, and then plan accordingly in anticipation of the what-if's.

I'm not sure a horse is simpler than a car though. I'm a city boy with a wrench, I wouldn't know the first thing to do with a horse but I can tinker in an engine. So to some extent "simpler" might be a matter of perception. :p

[superduperwesman]

I'm liking Mark's slotted idea in the corner of the sump for adjustability though

How do you adjust it? Wouldn't water flow out the slot if you move it up?

[Delphinus]

The one drawback about how I do it is if I drill the hole in the wrong spot then I'm stuck with a hole I either have to live with or patch, and either way sucks. The hole needs to be about 1.5" (maybe more, I can't remember for sure offhand) above where you want your waterline. So a slotted attachment point instead of a hole allows you to position the valve where you want it, as long as you can still attach it solidly (ie., any wiggling would be "bad"). And then if you want more water or less water in your sump you can adjust the valve to a new position and retighten, rather than drill a new hole.

But the slot then has to be IN the sump of course, and not the tank wall.

[RCFA]

I guess I'm still a bit confused...so does the float valve on your RO clean water discharge line create enough back pressure to shut the automatic shut off valve? Or does everyone have a pressure tank that then goes to a float valve? Maybe I should sketch a Process flow diagram so it is clear in my head.:wink:

[mark]

Did the slotted acrylic (with a router but probably a table saw would work) as wasn't sure where I wanted the level. Piece is inside the tank, no pressure on it so the silicone holds it okay.

Was planning on placing a reservoir in the joist space above the sump and gravity feed (even bought a 20g poly tank that ended up being just a little too big so returned) but then the issue was I'd need to remember to fill it up every 10 days or put on a ATO (maybe using a humidifier valve:biggrin:). This works, no wires to short, switches to jam, solenoids to fail open. Have come across on RC where people have flooded their tanks but never seen with a simple 10 buck valve, but with $500 controllers.

As for the membrane, wondering if TDS creep another little misinfo. First membrane lasted around 2 years, more than that on this one. I will notice after many many months a increase in TDS, but change the DI and back to zero.

[mark]

I guess I'm still a bit confused...so does the float valve on your RO clean water discharge line create enough back pressure to shut the automatic shut off valve? Or does everyone have a pressure tank that then goes to a float valve? Maybe I should sketch a Process flow diagram so it is clear in my head.:wink:

Output from the ro/di tee'd to the float valve and pressure tank. Ran the unit with tank off and ASOV still shuts the input to the membrane. Did have some problems that ro/di was always making waste even with output off and kept going to the ASOV, ends up was the check valve off the membrane.

[sphelps]

I'm not sure a horse is simpler than a car though. I'm a city boy with a wrench, I wouldn't know the first thing to do with a horse but I can tinker in an engine. So to some extent "simpler" might be a matter of perception. :p
Kind of the point, once educated with something far more complicated it becomes simpler because it's the better alternative. But realistically a horse is much easier understand than a car, it's only the surrounding technology that makes the car easier. For example if I send you into the woods with a hatchet, which are you more likely to come back with? A horse or a car?

[Delphinus]

I guess I'm still a bit confused...so does the float valve on your RO clean water discharge line create enough back pressure to shut the automatic shut off valve? Or does everyone have a pressure tank that then goes to a float valve? Maybe I should sketch a Process flow diagram so it is clear in my head.:wink:

Yes, but to be clear, I only fill my RO/DI reservoir from my RO/DI filter, and use the same float valve on the reservoir as I do on the sump, the reservoir valve shuts off the autoshutoff valve on the RO/DI input. I only use it to prevent overfills of the reservoir, once full, I shut off the input manually and only turn it on again when it's time to refill the reservoir.

The reservoir in turns feeds a 1/4" line with T's off to each sump I run with the float valves in the sumps. This line is just gravity fed. I also T off this line to my SW mixing reservoir which also has a float valve. So I let that fill and dump the salt in there and have it mixing ready for the next water change.

Running the float valve on the sump right off the RO/DI itself is generally not recommended. I burned through membrane after membrane doing this and when asked about it on the boards (here and others) the answer was that RO/DI's don't do well with constant on/off cycling - whereas a single long runtime is best.

I don't know how Mark is getting away with not wrecking his membranes that way ... more power to him for getting away with it - but for the record this is not really a recommendable approach. Use a reservoir in between at the very least.


As for the membrane, wondering if TDS creep another little misinfo. First membrane lasted around 2 years, more than that on this one. I will notice after many many months a increase in TDS, but change the DI and back to zero.

Kinda lost me on the first sentence, sorry :redface: What's misinformation?

I'm curious though, do you measure the TDS after the RO but before the DI? The DI will always pull it down to zero if the resin isn't spent. The question is how often do you replace your resin and could you be getting more life out of your resin?

[sphelps]

I guess I'm still a bit confused...so does the float valve on your RO clean water discharge line create enough back pressure to shut the automatic shut off valve? Or does everyone have a pressure tank that then goes to a float valve? Maybe I should sketch a Process flow diagram so it is clear in my head.:wink:
It wouldn't make a difference, the pressure on the float would be the same with or without a pressurized storage tank once the tank is full. The tank is simply an accumulator which stores volume, nothing more. The float will be able to hold the pressure from the RO but in my mind you'd be pretty foolish to hook a mechanical float directly to an RO unit without some kind of safety. This is a big no-no in the hobby and I'm surprised people actually do it. Tony has the right idea if you want to use a mechanical float for an ATO.

[superduperwesman]

But the slot then has to be IN the sump of course, and not the tank wall.

ahah Yeah I failed to realize that part. At first it looked like the slot was in the wall of the tank...:redface: one of those days I guess ahaah

[Delphinus]

Kind of the point, once educated with something far more complicated it becomes simpler because it's the better alternative. But realistically a horse is much easier understand than a car, it's only the surrounding technology that makes the car easier. For example if I send you into the woods with a hatchet, which are you more likely to come back with? A horse or a car?

I'll agree with you 100% if we can change your sentence to this:
"Sometimes, once educated with something far more complicated, it becomes simpler because it's the better alternative."

:lol:

[mark]

Mis-information that short cycling eats membranes. Slow death sure and years I find acceptable.

Going off topic here, made me check my notes and do some measurements. -looks like I replaced the membrane Jan 16/07
-last replaced the DI, July /09
-current tap TDS 190, after RO TDS 40, after DI TDS 13.

So bad me allowing my DI to exhaust itself, and yes my membrane is showing wear but it's been 3 years and it's a 100gpd so a rejection rate of only 90% to begin with. Guess I'll change my DI tonight and be good for about another 6 months.

[Delphinus]

It wasn't misinformation in my case when I replaced three membranes in a row after only 2 months each. And they were wrecked beyond reckoning. Like, input TDS of 200, output TDS of 190. It really stung me since they tend to be about $100 a pop. :( I'm trying to save others from that financial hit when I post about the short cyclings .. I honestly don't know what the difference between your setup and mine is, I'm happy it's working out for you but to be blunt, I don't understand how you're immune to it while I wasn't .. I'm jealous dude.

[sphelps]

I'll agree with you 100% if we can change your sentence to this:
"Sometimes, once educated with something far more complicated, it becomes simpler because it's the better alternative."

:lol:
Yes there are exceptions to everything so I'll compromise with "most of time" :wink:

[sphelps]

Running the float valve on the sump right off the RO/DI itself is generally not recommended. I burned through membrane after membrane doing this and when asked about it on the boards (here and others) the answer was that RO/DI's don't do well with constant on/off cycling - whereas a single long runtime is best.

I don't know how Mark is getting away with not wrecking his membranes that way ... more power to him for getting away with it - but for the record this is not really a recommendable approach. Use a reservoir in between at the very least.


You can run a direct line if you want and really it's the only way to get a real ATO rather than a semi auto. With an electronic system you can program the intervals to avoid the short bursts although I'm not sure it's that important. I've always run mine, and others I've setup, to work purely on demand with a short delay caused by a 10 second reaction time on the float. No obvious issues have been a result and my membrane is over 5 years old and still working close to as good as new. I think maybe in extreme cases where large dynamic pressure changes occur rapidly (like a manual float opening and closing rapidly from water movement) could cause damage to an RO through possible cavitation or some other anomaly and perhaps better quality units work better that others. These systems are primarily made for drinking water applications which is means they are primarily used in short run time applications so they should in theory handle that but they are not designed for humidifiers, or at least not primarily.

These are some recomdations from a manufacturer to increase membrane life:

Replace your sediment filter at least every 6 months or as determined by pressure drop test. This will prevent membrane fouling due to silt or sediment depositing on the membrane.
Replace your carbon block filter at least once every 6 months or when chlorine breakthrough occurs. This will ensure good membrane life and protect the membrane from chlorine damage.
Your Membrane should not be operated at lower than the recommended concentrate (waste) to permeate (output or purified) water ratios.
Operating reverse osmosis systems on softened feed water greatly reduces the chances of membrane fouling.

[banditpowdercoat]

Don't the pressure tank ones run little amounts of water too? I mean it's a 1g pressure tank, but they don't fully empty. infact, I bet most only run 1-2 cups at a time.

[sphelps]

Don't the pressure tank ones run little amounts of water too? I mean it's a 1g pressure tank, but they don't fully empty. infact, I bet most only run 1-2 cups at a time.
Well most tanks are 4.4 gallons and if they are properly charged (which you can check and adjust) they should empty completely if allowed to. But that's not that relative because a tank doesn't change the run time on the RO. Without a tank the RO runs until you fill your glass, sump or whatever is full but it takes a while to do so. With a tank you fill your "whatever" quickly, draining the tank, while the RO runs until the tank is full again. So the duty cycle on the RO is identical.

[banditpowdercoat]

Well most tanks are 4.4 gallons and if they are properly charged (which you can check and adjust) they should empty completely if allowed to. But that's not that relative because a tank doesn't change the run time on the RO. Without a tank the RO runs until you fill your glass, sump or whatever is full but it takes a while to do so. With a tank you fill your "whatever" quickly, draining the tank, while the RO runs until the tank is full again. So the duty cycle on the RO is identical.

Thats what I mean, A pressure tank RO sys will come on/off with every glass you pour. What's the difference if plumbed direct to sump? still running the RO for a glass or 2 at a time. I was refering to Possible membrane wear on short running cycles. But if the Pressure tank ones do it all the time, then there can't be an issue with it.

[sphelps]

Come to think of it a storage tank could prevent premature membrane failure since it is an accumulator which gradually reduces the pressure differential across the membrane during both the initial start and the stop of operation. Systems without a tank would experience a more sudden change which could be harder on the membrane (especially shut off). accumulators are used in hydraulics for similar reasons and to prevent cavitation which can damage various components. So if you're having problems buy a pressure tank :)

[sphelps]

Thats what I mean, A pressure tank RO sys will come on/off with every glass you pour. What's the difference if plumbed direct to sump? still running the RO for a glass or 2 at a time. I was refering to Possible membrane wear on short running cycles. But if the Pressure tank ones do it all the time, then there can't be an issue with it.
Yeah I agree, just don't use a mechanical float :p

[banditpowdercoat]

Yeah I agree, just don't use a mechanical float :p

And why not, seems to have worked well fro millions of Humidifiers and a lot of Reefers too :D


And I could see the accumulator princaple maybe helping the membrane life, but my float, when water level lowers, it acctually throttles open, and same when it gets full to shut off, it throttles closed as the container water level gets closer. Like how your toilet slows the flow down just before full, easing off on pressure to reduce water hammer.

[sphelps]

Haha, it's your tank dude. You can do whatever you want, but just cause you can do something doesn't make a good idea and it's not the membrane you need to worry about. :lol:

[banditpowdercoat]

You seem to be 100% dead set that a float valve WILL fail, flood tank and all is lost, yet there's Ton's of evidence to the contrary. What's up? Accidents can and WILL happen for sure. but if not 1 valve out of 1,000,000, then a Closed loop Pipe is gona burst due to internal stersses in the plastic and flood the place. Does that mean we should all get rid of our PVC and switch to sometihng else??

[sphelps]

You seem to be 100% dead set that a float valve WILL fail, flood tank and all is lost, yet there's Ton's of evidence to the contrary. What's up? Accidents can and WILL happen for sure. but if not 1 valve out of 1,000,000, then a Closed loop Pipe is gona burst due to internal stersses in the plastic and flood the place. Does that mean we should all get rid of our PVC and switch to sometihng else??
Dude relax, I'm saying 'can' not 'will' and you CAN do whatever you're comfortable with, what do I care? Do yourself a favor and take someones advice once in a while or at least don't get offended by it. And PVC pipe breaking under internal stresses?? :lol: What are you talking about?

[superduperwesman]

Yes there are exceptions to everything so I'll compromise with "most of time" :wink:

Exceptions prove the rule ;)

[byee]

i'm using 2 float switches back to back with a solenoid valve for my reservoir. When the solenoid valve is closed, there is no water coming out the discharge side of my RODI system.

Got the similar setup for my sump.

Why 2 float switches? #1 senses low to run on pump/valve and #2 keeps the sump and reservoir from overflowing.