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TryHard 01-21-2010 02:23 AM

Air injector broken -- Maytag topload washer
 
On my Maytag LAT9700 washer (with the front panel off and the chassis-top lifted), during fill, the aerator tube leaks substantially. The washer is about 12 years old.

The aerator tube (I have seen it called an "air gap fill injector tube") is located in the fill line about 9 inches before the water-entry nozzle to the tub. The aerator consists of a perforated outer plastic tube, an inner soft rubber tube, and an interior long plastic complex-shaped cylinder.

It's supposed to let air in. Currently it lets water out instead.

I disassembled it. The rubber tube has a tear in it. (You'll hate this -- I dried it and covered it with duct tape, which did seem to seal it.) In the process of disassembling it, I think(?) I dislodged the inner plastic complex cylinder from its anchor point. I reassembled it all as well as possible (I couldn't reposition the inner plastic cylinder) -- result: it leaks water the same as before. No surprise, I know -- I botched this.

Question: if this thing is only an aerator, can I just replace it with a straight piece of hard tubing (a coupler)? Or at least, can I do that temporarily while I see if I can get new parts? I'm desperate to have a working washer.

(There are no wires running to this thing -- it is not electrical.)

Thanks for any advice.

bob22 01-21-2010 07:20 AM

I've no answer (why does a washing machine need aerated water to wash?). Try:
http://www.repairclinic.com/Applianc...AT9700-%3d%3dp

TryHard 01-21-2010 03:15 PM

Quote:

Originally Posted by bob22 (Post 386558)
I've no answer (why does a washing machine need aerated water to wash?). Try:
http://www.repairclinic.com/Applianc...AT9700-%3d%3dp

The LAT9700 is fairly famous on the Internet. One fellow referred to the air gap fill injector as a "retarded device". Apparently this device did not appear in earlier or later Maytags. Maybe it was a bells-and-whistles thing. In any case, the injected water stream never looked bubbly to me anyway.

This evening, I'm going to replace the aerator (which is only a few inches long) with a straight pipe.

That gives me time to look for parts. The question is whether I really have to replace the aerator with a new one at all. Does anyone know any reason that this aerator is somehow essential?

You're right -- repairclinic is a good, no-nonsense site. In their repair kit Item #400646, the rubber tube looks like the rubber tube in my aerator, but the interior "nozzle" (?) looks quite different from what I've got. Their Item #435666 is the entire feed line running from the H/C inlet valves to the tub-entry nozzle (including the aerator section); that would probably work.

TryHard 01-22-2010 04:06 AM

All's well that ends well.
 
OK, I took out the aerator assembly and replaced with a straight pipe. No leaks now, of course. You'd think the water inflow would be heavier now with that gizmo removed, but in fact I can't see any difference.

Now that I have the whole thing out to examine at my leisure, I see that two of the remarks I made in the posts above were wrong: (a) I had *not* dislodged the inner cylinder from its anchor point (it was hard to take apart the first time, and I thought I unsnapped something); (b) the available parts from from RepairClinic, including the inner cylinder ("nozzle") in fact both *do* match the interior parts of the aerator I took out, so their tube & nozzle kit #400646 would be the right thing to get (for somebody who wanted to fix the aerator).

On the Net you can find claims that this aerator does two other things, and now that I've gotten a good look at it, I disagree with those claims. Supposedly, it's an anti-siphon; but there is no hydraulic situation here that could possibly result in siphoning. And supposedly it resists backflow; but its structure provides no blockage to backwards water flow -- and besides, according to my rough calculations, the forward city water pressure is about 170 times the backflow pressure of the 12 inches of water standing in the inlet tube, and you're not going to get any backflow that way in any case.

The point of that digression is that this thing is, IMO, only an aerator, period. And I don't need it; so I don't plan to buy the parts to fix it.

(I realize that in the drain there's an air gap that prevents backflow, but that's a different situation from this thing in the water-entry line.)

verna59 03-06-2011 12:59 PM

I have the same problem with my Maytag washer and was wondering if I needed to replace the air gap assembly. Could you please tell me if when you replaced it with just a straight piece of piping that it still doesn't leak? Thank you

TryHard 03-06-2011 03:44 PM

Air injector broken -- Maytag topload washer
 
Quote:

Originally Posted by verna59 (Post 603659)
I have the same problem with my Maytag washer and was wondering if I needed to replace the air gap assembly. Could you please tell me if when you replaced it with just a straight piece of piping that it still doesn't leak? Thank you

Don't replace the air gap assembly; it's useless. In principle, it makes the air bubbly, just like the aerator on a kitchen faucet. In fact, this is absolutely pointless. And the horizontal design guarantees ultimate failure with bad leakage.

That air gap assembly was a nutty "millenium model" idea from Maytag. It occurred only during one year, and was never present before or after that in Maytag washers.

I replaced the assembly with a piece of straight pipe. It was a piece of plastic plumbing pipe from the hardware, but metal would do just as well. The pipe just has to be the right length (or cut to the right length), and it has to fit snugly enough in the two rubber hoses. And of course you need to have circular clamps around the two hoses to make sure the pipe is snug. I used the two original circular clamps, but if your original ones are unsatisfactory for any reason, then you can get tightenable circular clamps from the hardware.

The piece of pipe has been installed a long time now. There is absolutely no leakage, and the water flow into the tub is perfectly normal.

hardwareman 03-06-2011 08:07 PM

that device is in no way, shape, or form an aerator, it is an injector tube and sleeve . Its sole purpose in life is to prevent any type of backflow from your washer tub back into the city water supply. National sanitation stardards mandate such a device. All washers have them in one form or another, that configuration on your Maytag was used for well over 30 years without change.

TryHard 03-07-2011 05:40 PM

Air injector broken -- Maytag topload washer
 
Quote:

Originally Posted by hardwareman (Post 604001)
that device is in no way, shape, or form an aerator, it is an injector tube and sleeve . Its sole purpose in life is to prevent any type of backflow from your washer tub back into the city water supply. National sanitation stardards mandate such a device. All washers have them in one form or another, that configuration on your Maytag was used for well over 30 years without change.

Well then, we are in disagreement. The tube cannot take water out of the tub -- the entry point of the tube is *above* the top lip of the tub, well above the maximum water level in the tub: there cannot be any siphon effect. The only hypothetical backflow would be from the 12 inches of water standing in the inlet tube *below* the device in question. If you take the device apart, it is clear that there is absolutely nothing in its interior that would prevent water from flowing backward. Furthermore, the forward city water pressure is about 170 times the backflow pressure of the 12 inches of water standing in the inlet tube (below the device), and you're not going to get any backflow that way in any case.

Note that the Maytag device in question has many slots (holes) in it that are literally open to the air (the slots are on top -- the device is horizontal). Because of the Venturi effect, water flowing through the device will suck air into the device and mix it into the water.

It is quite possible that there is a one-way valve to prevent backflow in the interior of the inlet valve assembly at the bottom of the machine (to which the water supply is connected). But the Maytag device being discussed here does not have anything in its innards which could possibly prevent water from flowing backwards.

andrew4096 07-07-2011 03:35 PM

Works on other Maytag models, too
 
Thanks to the preceding discussion in this forum, I just fixed a Maytag LA282 washer (manufactured ca. 1987), replacing a defective airgap assembly with a plastic 3/4" barbed coupling and two stainless steel hose clamps. The barbed coupling was nearly identical in length to the original airgap housing. I secured the coupling to the washing machine housing with a 6-inch nylon cable tie. The hose clamps are oriented on top of the hoses, worm screw heads facing inward, such that they straddle the edge of the sheet metal, so that when the cable tie is cinched tight, the plastic coupler is rigidly held in a horizontal position by the sheet metal, much in the way the original airgap assembly was held by its single sheet metal screw. The Maytag airgap assembly had a built-in slope so that water would drain out of the rubber tube by gravity, but since the modified assembly isn't open to the air, the slope is now of little importance.

The original airgap assembly was encrusted with hard water deposits, and thinking that was the cause, i disassembled it and cleaned it, but on reassembly it still spurted water all over the place. I tested it by pointing the injector nozzle into the washing machine tub and running a bit of water through it, but what should have been a narrow jet of water was a turbulent, conical spray, the hydrological equivalent of air coming out of a "whoopie cushion". I suspect the rubber sleeve of the injector had become worn or the properties of the rubber changed over time, causing this effect. Rather than paying about $20 for new airgap parts and possibly having to wait several days for delivery, I solved the problem in less than an hour for $11.97 in common parts from the local Ace Hardware store.

Note that the barbed coupling is made of PVC and is not rated for very hot water at line pressure. However, the fill hose is short and open at one end, so there is never significant pressure buildup in it. I've successfully used ordinary PVC parts (instead of CPVC) with hot water under 130F at low pressure in the past and have never seen failures after many years of operation. Moreover, most laundry loads are run with cold or warm water, not hot. :thumbsup:

TryHard 07-07-2011 10:56 PM

Works on other Maytag models, too
 
Quote:

Originally Posted by andrew4096 (Post 681481)
Note that the barbed coupling is made of PVC and is not rated for very hot water at line pressure. However, the fill hose is short and open at one end, so there is never significant pressure buildup in it. I've successfully used ordinary PVC parts (instead of CPVC) with hot water under 130F at low pressure in the past and have never seen failures after many years of operation. Moreover, most laundry loads are run with cold or warm water, not hot.

The temperature rating of PVC varies regionally (or at least internationally). And of course, the temp rating varies considerably with pressure. As you pointed out, with both ends always open, there is virtually no pressure on the PVC itself in your case. For that case, most sites on the Internet indicate a PVC temperature rating of 60C = 140F. I regulate my hot water heater (manually) to keep it at 140F, so there should be no problem.

As a side issue, PVC used for potable water has a 49C = 120C temperature rating at near-zero pressure, but since I don't drink out of the washing machine tub, that shouldn't be a problem either. The potable-water rating is probably lower because of putative release of pollutants from hot plastic.

readar 07-08-2011 01:16 PM

Quote:

Originally Posted by TryHard (Post 604686)
Well then, we are in disagreement. The tube cannot take water out of the tub -- the entry point of the tube is *above* the top lip of the tub, well above the maximum water level in the tub: there cannot be any siphon effect. The only hypothetical backflow would be from the 12 inches of water standing in the inlet tube *below* the device in question. If you take the device apart, it is clear that there is absolutely nothing in its interior that would prevent water from flowing backward. Furthermore, the forward city water pressure is about 170 times the backflow pressure of the 12 inches of water standing in the inlet tube (below the device), and you're not going to get any backflow that way in any case.

Note that the Maytag device in question has many slots (holes) in it that are literally open to the air (the slots are on top -- the device is horizontal). Because of the Venturi effect, water flowing through the device will suck air into the device and mix it into the water.

It is quite possible that there is a one-way valve to prevent backflow in the interior of the inlet valve assembly at the bottom of the machine (to which the water supply is connected). But the Maytag device being discussed here does not have anything in its innards which could possibly prevent water from flowing backwards.

Of course there won't be any backflow with city water pressure maintained. These devices are there to protect the city water supply when the supply pressure fails and could potentially siphon back contaminated water.

andrew4096 07-08-2011 02:47 PM

Quote:

Originally Posted by readar (Post 682061)
Of course there won't be any backflow with city water pressure maintained. These devices are there to protect the city water supply when the supply pressure fails and could potentially siphon back contaminated water.

Not an issue. Re-read the first sentence of TryHard's comment to which you responded. The fill tube opens at the very top of the tub. For contaminated water to siphon back, the tub would have to be filled to overflowing. If that's the case, the water level sensor would have had to malfunction just prior to a water pressure failure while filling the tub and the electric fill valve was open and there would have to be a vacuum in the house plumbing. Putting an airgap in the line is simply overkill and bureaucratic nonsense, trying to cover a highly contrived one-in-a-billion chain of events that would probably not result in illness or death even if it happened. A body is hundreds of times more likely to die in a traffic accident than experience such an event with a modified home appliance.

If Maytag and other washer manufacturers truly cared about the public water supply, they would have put a spring-loaded check valve in the line, instead of that 50 piece-of-junk airgap solution that they actually decided to use. In high volume manufacturing, it all comes down to saving pennies, which adds up to millions of dollars annually. How else would the CEO be able finance his mansion and country estate? :furious:

TryHard 07-09-2011 01:40 AM

Quote:

Originally Posted by readar (Post 682061)
Of course there won't be any backflow with city water pressure maintained. These devices are there to protect the city water supply when the supply pressure fails and could potentially siphon back contaminated water.

Specifically for the LAT9700:

(1) The water input tube opening is well above the tub: even if the tub overflowed, that water could not reach up to the mouth of the opening of the water input tube. No siphoning effect is physically possible.

(2) If you disassemble the device we're talking about, you can see that nothing in it will prevent backflow.

(3) There is about one vertical foot of city water left in the water input tube when the machine is off. The valve that connects to the city water is closed. If I electrically open that valve at at a time when the city water pressure is zero, a small amount of ordinary, clean water from the water input tube could conceivably leak back into the city water line -- see point (4).

(4) In my shower there is a water input tube which always has 5 feet of water left in it. If the city water pressure is zero and I open the shower faucet, then that water will, in principle, back up into the city water line. I am painfully familiar with that shower line; there is no one-way valve to prevent backflow. And the neighbours I have who do some of their own plumbing also fail to have backup-prevention valves on their shower lines.

(5) When the city water pressure goes to zero where I live, it's because a main has broken. You can go outside and find it and watch them working on fixing it: they bandage it, effectively. You should see the crap and corruption in the line when they turn the water back on. I have to remove and clean out the stones in every faucet aerator I have. That fact does not leave me terribly worried about the putative backup of basically clean water from my shower (or washer) into the city line.

hardwareman 07-09-2011 09:05 AM

Quote:

Originally Posted by readar (Post 682061)
Of course there won't be any backflow with city water pressure maintained. These devices are there to protect the city water supply when the supply pressure fails and could potentially siphon back contaminated water.


exactly right, they can argue all they want about whether a situation like that will ever occur but non the less it is a backflow preventer. It is on the Maytag washer, it is on all washers in some form or another. Its on there because it is mandated by the National Sanitary Safety Code. They can remove theirs or install a pipe or a fitting or whatever in its place if they choose with no adverse affects on the operation.

andrew4096 07-09-2011 04:51 PM

Quote:

Originally Posted by TryHard (Post 682425)
(5) When the city water pressure goes to zero where I live, it's because a main has broken. You can go outside and find it and watch them working on fixing it: they bandage it, effectively. You should see the crap and corruption in the line when they turn the water back on. I have to remove and clean out the stones in every faucet aerator I have. That fact does not leave me terribly worried about the putative backup of basically clean water from my shower (or washer) into the city line.

That's right. Sometimes one must simply say "screw it" to the regulators and their overbearing regulations, just "git-'er-done" and move on with life.


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