Bathtub Pressure Sensor Switch

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Hi Everyone,

I'm new here - usually over in the Arduino or similar type forums, although I'm quite a novice still.

I am trying to help my father fix his bathtub, which has 6x jets that are turned on via a sensor switch glued to the outside of the tub (in the crawl space). There is a control box that triggers the 110v water pump to start circulation the water. That pressure sensor switch, along with a water level switch built into the jet pipes, triggers on/off.

The problem is that the pump won't start, and I believe it is the switch, as I was able to get it to turn on while using a multimeter to test the resistance. Frankly, I don't know how it happened, and I have since been unable to get it turn on again. Needless to say, the motor does work.

I unplugged the sensor switch and took readings between all 3 prongs. The Resistance on the switch is all over the place, but generally between 2 and 8 million Ohms. I tried to use a short piece of wire to force control box to turn on, but wasn't successful. Hopefully I didn't burn anything out...

Normally I would just order a switch and call it a day, but of course these switches are not made anymore. I would be happy to cut a whole in the bathroom wall and install a new switch, but I am not sure what type of switch I would need for this 3-prong plug. I don't really understand AC current and am clearly missing some basic knowledge here.

Could someone help me along in the right direction. Standing by to answer any further questions or run up to do more multimeter tests.

Thank you very much.

Kal


20210115_090923.jpg20210115_090916.jpg20210115_090857.jpg20210115_090847.jpg20210115_090842.jpg
 

wayneh

Joined Sep 9, 2010
17,152
Hi Everyone,

I'm new here - usually over in the Arduino or similar type forums, although I'm quite a novice still.

I am trying to help my father fix his bathtub, which has 6x jets that are turned on via a sensor switch glued to the outside of the tub (in the crawl space). There is a control box that triggers the 110v water pump to start circulation the water. That pressure sensor switch, along with a water level switch built into the jet pipes, triggers on/off.

The problem is that the pump won't start, and I believe it is the switch, as I was able to get it to turn on while using a multimeter to test the resistance. Frankly, I don't know how it happened, and I have since been unable to get it turn on again. Needless to say, the motor does work.

I unplugged the sensor switch and took readings between all 3 prongs. The Resistance on the switch is all over the place, but generally between 2 and 8 million Ohms. I tried to use a short piece of wire to force control box to turn on, but wasn't successful. Hopefully I didn't burn anything out...

Normally I would just order a switch and call it a day, but of course these switches are not made anymore. I would be happy to cut a whole in the bathroom wall and install a new switch, but I am not sure what type of switch I would need for this 3-prong plug. I don't really understand AC current and am clearly missing some basic knowledge here.

Could someone help me along in the right direction. Standing by to answer any further questions or run up to do more multimeter tests.
I’m a bit confused by your terminology. Is the switch activated by air pressure? I’ve seen some like that. And I can imagine they fail more often than a regular electrical switch.

While the original parts may not be available from the supplier anymore, I’m confident we can come up with a solution. We just need to understand it all a little better.

In the meantime I suggest unplugging everything and not poking around while circuits are hot.
 

kcvogels

Joined Dec 22, 2020
2
it is a bit a blurry photo.is there a type number that you can tell us. this sensor measures if there is enough water ,so without water the pump will never work. however there will be a workaround by fooling the electronics there is water.
 

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Thanks very much for the responses everyone. I'm attaching some better photos. Just to be clear, there are two sensors. The water level sensor (grey) I think works fine. It is the on/off sensor that is acting up. You can see from the photos that the water level goes right into the white PVC pipe, while the on/off switch was attached with glue and duct tape to the outside of the fibre glass tub. I've removed it and taken close-ups of it. Seems like I can simply buy this part and I'd be good - assuming it works!

https://www.whirlpooltubparts.com/pls-2000-whirlpool-tub-control.html
IMG_0013.jpgIMG_0004.jpgIMG_0005.jpgIMG_0006.JPGIMG_0009.jpgIMG_0010.jpgIMG_0011.jpgIMG_0012.jpgIMG_0014.jpgIMG_0015.jpg
 

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Hi Guys,

I contacted Franklin Water - they sold that branch of the business to Whirlpool so they are out..

Whirlpool doesn't have parts or any idea what I'm talking about..

I found this website and bought this replacement kit - https://www.whirlpooltubparts.com/pls-2000-whirlpool-tub-control.html

I was expecting (based on the photo that matches my sensor switch) to have a replacement "Ameri-Touch" sensor switch, what it seems this faulty switch is called. I spent the $180 and got the kit, but plan to return it because it isn't a replacement but rather a completely replaced control setup (see photo and instructions attached).

Wouldn't it be easier to simply cut the sensor switch off and wire instead a simple switch that I can mount next to the tub? I don't know what type of switch I'd need and what measurements/tests to do to ensure it works. I assume it should be strait-forward but would appreciate some guidance on how to get started here. Thanks!

PS - also attached is a photo of the user manual and specific model tub.
 

Attachments

wayneh

Joined Sep 9, 2010
17,152
Wouldn't it be easier to simply cut the sensor switch off and wire instead a simple switch that I can mount next to the tub?
Did we ever confirm your original switch is pneumatically actuated, like the replacement one?

As for putting a switch near the tub, that may not be code. Where I live (northern Illinois), code requires the switch to be something like 8' from the tub, so there's no way to use the switch while in the tub. That's super impractical and annoying, so I got one of those RF remote switches powered by a 9V battery. Now I can turn the jets on and off without calling for help. (You can't leave the tub with the jets on, because they'll spray all over the bathroom when the water level drops as you climb out.
 

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Did we ever confirm your original switch is pneumatically actuated, like the replacement one?
Nope, it is a sensor switch (assuringly pressure sensor) and called Ameri-Touch. Pictured above, it is the square box that was glued and taped to the outside of the tub. On the inside of the tub was a little sticker that one would push on. That has since fallen off, so we just know where to push ;). IMG_0014.jpgIMG_0015.jpg


As for putting a switch near the tub, that may not be code
If possible, I'd be even happier to simply override the ON/OFF Ameri-Touch sensor switch. I have a master switch inside the bathroom that powers the whole setup... so if we can keep the water-level sensor working (which it appears to be...) then we are good to go. As you can see in the photos above, the control box has a grey and a white plug. White goes to On/Off, Blue goes to water-level sensor.
IMG_0018.jpg
 

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Some Bathtub Controllers use a 3-wire Capacitive Sensor for Water Level Control.
It could be, but I haven't messed with the water-level sensor since it seems to work. The On/Off is what is not working. Pictured below in the water-level sensor, that plugs into the control box with the grey plug. You can also see behind against the outside of the tub where the On/Off sensor was duct-taped before I removed it. IMG_0013.jpg
 

wayneh

Joined Sep 9, 2010
17,152
If possible, I'd be even happier to simply override the ON/OFF Ameri-Touch sensor switch. I have a master switch inside the bathroom that powers the whole setup... so if we can keep the water-level sensor working (which it appears to be...) then we are good to go.
Well that would be easy enough, both to test and to implement if you like how it works. The mystery is that the switch had 3 leads, right? So not immediately obvious how simulate it's normal behavior. Me? I'd take a Dremel to the perimeter of the plastic box and open it up, assuming there's no easier way. I've cut into a lot of laptop power bricks that way. You just have to be careful to watch your depth, as it tends to go deep once it breaks through. A hacksaw is another option. A wide-blade wood chisel is a handy tool also. Sometimes you can split an existing seam with a few taps.

Take care to keep the connector on the far end - you'll need it later. But be aware that the problem could even be in that connector and the cabling to it. Assume nothing.
 
Last edited:

Kjeldgaard

Joined Apr 7, 2016
451
It could be, but I haven't messed with the water-level sensor since it seems to work. The On/Off is what is not working. Pictured below in the water-level sensor, that plugs into the control box with the grey plug. You can also see behind against the outside of the tub where the On/Off sensor was duct-taped before I removed it.
OK, I had not seen that it was an ON / OFF function.

But it can still be a Capacitive 3-Wire Sensor, mounted high on the tub.
 

advisorf

Joined Feb 13, 2021
3
I think its basically just two switches. 1 for on off and one for water.

What I dont know is a timer. Is that in the pump or somewhere in that junction box
 

Thread Starter

kalkulate

Joined Jan 23, 2021
12
Well that would be easy enough, both to test and to implement if you like how it works. The mystery is that the switch had 3 leads, right? So not immediately obvious how simulate it's normal behavior. Me? I'd take a Dremel to the perimeter of the plastic box and open it up, assuming there's no easier way. I've cut into a lot of laptop power bricks that way. You just have to be careful to watch your depth, as it tends to go deep once it breaks through. A hacksaw is another option. A wide-blade wood chisel is a handy tool also. Sometimes you can split an existing seam with a few taps.

Take care to keep the connector on the far end - you'll need it later. But be aware that the problem could even be in that connector and the cabling to it. Assume nothing.
Here is the inside of that sensor switch for ON/OFF
 

Attachments

wayneh

Joined Sep 9, 2010
17,152
Here is the inside of that sensor switch for ON/OFF
Wow, that's more complicated than I expected. Would it be hard to get a picture of the other side of that circuit board?
it isn't much of a "diagram" but you can see the words behind it... :/
I think there's another level beneath the terminal area in the picture. Maybe there's more to see in there, a relay and and maybe a diagram.
 
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