Smart Toilet bi-stable solenoid valve acting strange -what could be the reason and the fix?

[Mini Me]

I have a smart toilet (Ove Stan) that is built using this valve

Here is the valve manufacturer page but I can't say exactly which one of those is my valve.
http://www.chinazhanying.com/en/products.php?cid=3...
It is acting strange as described below

I called the toilet manufacturer and they want me to replace the entire assembly
Here are the directions they sent me

Here is how the toilet works: when I flush the toilet there is two valves that open in sequence:
he left one in the above picture is what they call the whirlpool valve which is cleaning the toilet bowl before flushing it.
it basically sends water to make sure that all goes to the bottom of the toilet.
After that this valve closes and a second one situated at the bottom of the toilet opens and it flushes/pushes everything into the drain.

The problem: the wirlpool valve is not working any more not as it used to. In normal conditions it won't open at all anymore.
However by accident I discovered that if I open the sink tap half way that decreases the water pressure in the pipe that supplies both the toilet and the sink and then if I flush the toilet while the water is running everything works relatively normal. Obviously there is a lower pressure at the bottom valve in the toilet but it is still enough to push everything into the drain

I am not sure if the valve is broken or it is that the water pressure is too high and I should try to lower it at the toilet supply end.
That end is controlled by a SharkBite 1/2 x 1/2 Inch MIP Straight Stop Valve, Quarter Turn, Push to Connect Brass Plumbing Fitting but I can definitely put something else there.

I do not trust the manufacturer who is telling me to buy the entire assembly and to replace it.
That generates more profit for them and it seems like a waste to me. Besides that it will be difficult to access the back side of the toilet to remove the assembly, I would practically need to remove the toilet because it is installed too close to the wall.
Based on the valve manufacturer pictures it should be easier to replace just the valve from above.
If based on what you see in the picture (Model F62B08BOL) you know of an equivalent please let me know
The water pressure measured at an outside water tap is shown below. That is located just before the pipe enters that bathroom.
It shows around 90PSI, the valve is rated for 0.8Mpa (116PSI)

Here are the toilet details, I can't find the pressure requirements
https://www.ovedecors.com/en/plumbing/smart-toilet...

 

[Mini Me]

Here is the plumbing recommended by the manufactured for this toilet

 

[Sponsor]

 

[Mini Me]

I am thinking maybe a water pressure reducing valve could be installed between that existing valve and the toilet, hidden behind it as there is some room there
PS: I would not install one on the main supply pipe as I already do not have enough pressure to keep two taps open on the same or on different floors.

 

[Breplum]

Your reporting that you don't have enough psi to keep two taps open, makes me think that you have a water restriction or a main valve not open.
A 3/4" house main can run many fixtures simultaneously with 75 psi. You need a Pressure reducing valve on your main.
You might pull the small check valve and check on it.
Alternatively, return to Costco for a refund. Toilets are NOT on the exceptions for refund list. Watch out for fancy toilets that cost under $1,500. They will bite you in the butt (figuratively)

 

[Reach4]

PS: I would not install one on the main supply pipe as I already do not have enough pressure to keep two taps open on the same or on different floors.

When you do not have enough pressure to keep two taps open, what does your pressure gauge on the hose spigot indicate?

When you do not have enough pressure to keep two taps open, is that the case if one is the kitchen sink? If yes, I would be looking for a clogged filter. Some PRVs have strainers (a form of filter).

 

[Mini Me]

The piping is 1/2 in the entire house
I can keep two taps open but the water pressure drops to half of what it was.
The toilet was bougth like three years ago and installed like two years ago. It was not that expensive compared with th prieces I am hearing today. There is no way I can return it now.

 

[Reach4]

I can keep two taps open but the water pressure drops to half of what it was.

45 PSI should be plenty.

 

[Fitter30]

Plastic solenoid valves are really not made for that pressure full time. 60 lbs max is what most houses ever need higher pressure just wears out in the system faster.

 

[Mini Me]

I am totally confused ...everybody is telling me that 90PSI is high pressure
but as mentioned above I see a lower volume coming out of each tap when two taps are open anywhere in the house.
here is my plumbing
where could the bottleneck be ?

 

[Reach4]

Non-responsiveness is one kind of bottleneck. Troubleshooting could be easier.

Pipe under the front yard could be crushed.

 

[Fitter30]

5 gallon bucket and time fill at a outsde faucet. Pickup a gauge and fitting sell at box and hardware stores. Measure water pressure with one sink and two lets see if incoming pressure drops

https://www.google.com/url?q=https://www.amazon.com/Pressure-Universal-Lead-Free-Fittings-Adapters/dp/B09RJVCJR9&sa=U&ved=2ahUKEwi3us-DuquDAxVCj4kEHej4CYgQFnoECAAQAg&usg=AOvVaw3Jj2JmySaiI-RyQrxYLPvk

 

[Mini Me]

Thanks for the feedabck guys
@Reach4 ...no tap in the waterhouse is siffering from low pressire when it is open by itself. A crushed pipe would be a constant bottleneck no matter how many taps are open.I need a way to measure the pressure at one of the sink ends.... if it still 90psi thr thr pipes should be unobstructed

@Fitter yes I am planning to do something similar. I already have the gauge you swe there ...I suspect I just need the adapters is this what you are suggesting?

 

[Fitter30]

80 lbs max ,page 31

https://www.ovedecors.com/pub/media/amasty/amfile/attach/IM_Stan_Tuva_2022-09-02.pdf

 

[GReynolds929]

I am totally confused ...everybody is telling me that 90PSI is high pressure
but as mentioned above I see a lower volume coming out of each tap when two taps are open anywhere in the house.
here is my plumbing
where could the bottleneck be ?

Pressure and flow are two different things. They often work together. Code maximum has been 80 psi for decades. 90 psi is high pressure. 1/2" mainline and distribution piping will definitely restrict flow. If the toilet was working fine for years and now is not something has changed or the part has failed.

 

[Reach4]

...no tap in the waterhouse is siffering from low pressire when it is open by itself. A crushed pipe would be a constant bottleneck no matter how many taps are open.I need a way to measure the pressure at one of the sink ends.... if it still 90psi thr thr pipes should be unobstructed

Besides the hose bib, you can put a GHT pressure gauge at a laundry tap or the drain on the WH. This will let you check the pressures, and deduce where the main pressure drop is coming from.

no tap in the waterhouse is siffering from low pressire when it is open by itself. A crushed pipe would be a constant bottleneck no matter how many taps are open.I need a way to measure the pressure at one of the sink ends.... if it still 90psi thr thr pipes should be unobstructed

Did you not say that the pressure gauge on the hose spigot dropped by half???? If you did not say that, then say what gauge pressure does when you turn on your two-faucet load.

 

[Fitter30]

Have u pulled any aerators ?

 

[Mini Me]

No aerators were removed lately.
@Reach4 yes I am going to havr to measure that.
I was saying that if you have a tap running and you open another one the amoint of water that flows to the tap fals to half. The tap that is closer to the source will obviously take more water while the one located downstream will get to berely enoigh to was you hands ....I will get us some numbers maybe tomorrow.
@GReynolds929 yiu are probably right but this is how it has been for years in the house, sinece we bought the house 10y ago.
The toilet worked well for 1.5y or so
The other valve is identical with this one and still working.
So am I reading from what you guys are saying that I should try to lower the pressure at the main valve level ?

 

[Mini Me]

80 lbs max ,page 31

https://www.ovedecors.com/pub/media/amasty/amfile/attach/IM_Stan_Tuva_2022-09-02.pdf

Good catch....I guess that is conservative or based on other components of the system. The valve is rated for more as the pictures are showing

 

[Mini Me]

I would like to try using one of these

https://www.amazon.ca/Pressure-Reducing-Adjustable-Control-Regulator/dp/B07TCGX75Y/

installed just downstream of the below valve

https://www.amazon.ca/gp/product/B07J6GM88G

BTW the valve seems to be 1/2" not 3/4" as depicted in the above manufacturer instructions.
So to recap:
-it is an 1/2" sharkbite valve connected via a 3/8" Compx 7/8" BC flexible cord to the toilet
There is an interesting detail you can see in the picture:
-the first valve is using a larger ID flexible cord (3/4") than the valve that is in trouble here (seems to be 1/2" ID)

Could you please help me with what fittings I need to attach the pressure reducing valve to the tap?
The gauge seem to have an 1/2" thread as well (please see the picture in the initial post)

I am not sure about the types of threads involved here ...that is where I mostly get lost with these things
So what I need is to insert the above reducing valve somewhere between the toilet shut off valve and the solenoid valve in question here.


I need this quick solution because I am having guests for the New Year eve but in the long term I will probably address the overall issue which seems to affect the sink in that bathroom as well, which is splashing all over the place if open to the max

 

[Fitter30]

1/2" male pipe thread adapter x 3/8" compression toilet side ( they make this fitting in ell shape 90°)
Wall side depends how much pipe is sticking out of the wall but it could screw on the end of the stop valve and another 1/2" male pipe thread x 3/8" compression adapter.
3/8" braided hose compression fittings. From reducing valve to solenoid valve.