The sense and non-sense of flow-restrictors!

[henene4]

Well, I noticed this topic comming up more and more. And as I found out today, our new Bauknecht Super Eco has flow restrictors as well as any other Whirlpool washer made today.
As far as I know, Whirlpool had yellow flow-restrictors on their washers until 2010. These had a flow rate of 8 l per minute, or, for these from the other site of the pond, round about 2.1 gallons a minute. At least on their FL's. The service-manual part that describes this is shown in the picture below. And, as you read their, they are supposed to be exchanged by simmilar ones with only 5.5 l (1.45 gallons) per minute.
I just wanted to hear what you think why they are used.
2 reasons are clear to me:
1st: Equalising the process of washing: Every body knows: The less variables are in a process, the less failure and ofsets can occur. So these are used to get the same fill-rate no matter how big the local water pressure is. For example, without a flow meter build in, load sensing can only work with the same amount of water per time entering the tub. If the flow would be faster, the PCB could not know that and would recognize a smaller load. If the fill would be slower, it would sense a bigger load.
2nd: With a slower fill rate, the sensing can be way more accurate. If all the water would just rush in, it would maybe not be abled to turn of exactly at the time necessary.
Do you have further ideas why they are used?

Best wishes
Henrik

 

[yogitunes]

for one, it could be regulating water temp, some do that.....

another thought is it direct injects into the dispensers, and the slower rate will allow a slower mix before dispersing the soap mixture onto the load...

for whatever reason, I took mine out long ago, and that trickle turned into a water fall...I am more than happy with it now....

but it did seem like forever for the machine to fill.....besides, its not like they have both valves on at the same time, with the auto water temp sensing, it jumps back and forth from hot to cold...

nice part is, for the Whirlpools at least, it can take seconds to pull the hose, take out the screen, remove the restrictor with a pair of needlenose, and put the screen back, and reattach the hose, without disassembling the machine....

those who haven't, really should try this.....not like you can't put it back just as fast......but I don't think your gonna want to...

I even took the restrictors out of my 1985 filterflos.....amazing how many machines actually have these....

funny how things have turned around, there was a restrictor on the cold water side of my 1964 Whirlpool, but that was from a time when a warmer wash was required...

 

[mrb627]

Hmmm...

Perhaps the intention is to slow the water fill for a more finite water level sensing routine using the electronic water level sensing as opposed to a mechanical pressure switch.

 

Malcolm

 

[logixx]

Don't know if mine has a flow restrictor as well. Not sure if I wanted to remove it, though. I think I'd be afraid of the compartments overflowing due to too much water - like that the bleach compartment might overflow into the softener, causing it to be released during the first rinse when the bleach is flushed.

 

[murando531]

I could see the sense in the "auto-sense" models (hehe), but for washers that have completely manual water level switches and no flushing dispensers, I don't see the point. It only makes it annoying to have over 30 minutes of every cycle for filling. For the HE models that have to precisely fill and have flushed dispensers, I'll give'em that, but for a machine that is going to fill up to the same points regardless of how fast or slow, it doesn't make sense.

 

[henene4]

@logixx

I guess so. But I would be more concerned about the load sensing then.
I won't remove them on ours anyway. It fills good, flushes good and uses sufficent ammounts of water in any cycle I tried yet. Intensive rinse is a good choice, but no absolut must have.
Only cycle I want to try soon is the AquaEco cycle. 19l for 3kg of laundry sounds not much at all.

 

[roscoe62]

@henene4

If the machine senses the load size before filling maybe the restrictors are there to dissolve the detergent drawer completely while filling? I'm only guessing and since your machine does work well with sufficient amounts I can understand why you would not remove them. I removed mine thinking they were a part of the shipping material, but I have had no problems either.Mine fills no more faster than the older model I had and uses a decent amount of water to rinse too,with no issues.
Cheers

 

[thor]

Flow restrictors

Maybe their main purpose is to control the volume of water (flow) during the now so popular spray rinses. Restricting the water flow to a really low volume of water equalizes how much water is used during spray rinses, regardless of your city mains water pressure. So, Joe Doe's washer, hooked up to very high water pressure, will use exactly the same volume of water as Jane Doe's identical washer, hooked up to low water pressure (during the same cycle, of course).

 

[murando531]

Could be. I just don't understand what's going through their minds when they "design" some of these so called spray rinses. On my WP, the machine spins after the wash, then runs cold water while pulsing the tub to slowly turn, but all the water is hitting the base of the agitator and running down under the load. Barely any of it hits the clothes at all before it does a final spin and calls it done. At least since I removed the restrictors and there's a substantial waterfall now, if I were to turn the Fabric softener option off for it to do a spray, the clothes would at least see some water.

 

[logixx]

Sure enough... mine has the flow restrictor as well.

 

I just emoved it from the cold inlet and am running a load of shirts. Other than that the inlet valve now making a noticable *thud* sound when opening, the fill is hardly any stronger/faster. Will put the thing back in.

 

Notice how the four large openings in the orange restrictor are blocked off by the rubber ring. The actual openings are so small you couldn't even fit a needle through them.