[SOLVED] I like to pick some brains for a 'teenage shower' solution

Assumes the teenager showers after dark… :slight_smile:

May not work due to same pressure in both lines.

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I would deduct pocket money based on a timer; every minute over the agreed duration will reduce pocket money by x. No plumbing required. :slight_smile:

… or block WiFi access for x time.

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Loud music they can’t stand?

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Usually showers when gets up… in broad daylight :slight_smile:

Yes but then need to keep a timer :slight_smile: but tru, no plumbing required

yes but taste can change by the day :slight_smile:

That is why I think the two valve option is better

I think the money spent on this is by far going to exceed the amount of money it costs to pay for the gas and water bill.

I hope he understands that taking a shower with the misses is also going to be a lot less fun :wink:

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wemos D1 mini: 3 euro
NTC 30cts
valve 7 euro
motordrive H-bridge 1 euro

:slight_smile:but you forget it can be switched off

Did you use 5 minutes as an example or do you really consider 5 minutes showering long?

I just threw that in as example. I know some drill sergeant dads though that time their kids for a 90 sec shower.
Currently software is testing with timer between 1 and 10 min

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Another way is to use a small restricted bypass pipe that goes around your hot water shutoff solenoid. When the valve is shut off the bypass pipe sends water (still hot water) around your valve and this could be controlled with a tap on the bypass line that you remove the handle from. Set the restricted line so that you cant shower, but enough water trickles out to ensure the tap gets turned off. Also the tap doubles as a way to route water around a faulty solenoid in case something fails and the house if left with no hot water at the shower, just turn the bypass tap normally used to retstrict the flow and open it up until you the tech support can come by to fault find.

Whilst the thermostat tap idea is good, I doubt it would be easy to fit without remodelling the bathroom and moving the connections in the wall behind the tiles.

Lastly another idea already suggested in to just cut the hot water for 5 seconds every ten seconds to make it not viable to stay in the shower. Then watch the hot pipe temp and when it cools enough stop activating the valve and allow normal hot water to flow.

ah yes, that is actually also a good idea.
Indeed the thermostat tap -if present- would be easiest it would require 'remodelling’if it isnt.

Currently I am testing the solution in which the hot water is closed off and cold water is led to the hot water pipe, that works pretty well, but it requires two valves and thus by definition more prone to error.
Yours is definitely a suggestion I will give some thought.

Thanks

5 minutes of hot water? Savage. I’d run away

that will save even more water :wink:

I have known drill sergeant dads who only allowed 90 seconds

Why not install a mixing valve? That way off is off for hot and cold. Then you can install an electric valve on the hot line and do whatever timing you need.

Thanks. Indeed that was one of the options mentioned and that would be the simplest. However the ‘client’ wishes for his current two fawcett system to stay intact.
On his second shower he has a thermostat fawcett so no problem there

I thought I’ d give some update on how this project was going. Pretty well actually. After a working prototype I put it all in a small box and this is what it looks like.

I have a 6 Volt linear stabilizer as the valves used need 6 Volt.
A diode then connects the 6 volt to the 5 Volt of the ESP (providing it with 5.4 Volt). Because of the valves drawing 700mA, there is a 100uF decoupling over the 5 Volt pin of the ESP.
The valves DO work on 5 volt, but the common 5 Volt ‘phone charger type’ even if they are guaranteed to deliver 2 amps, usually have very thin wires in the USB cable and I just didn’t want any hassle with voltage drops.

The ESP simply checks the temperature of the shower pipe via a DS18B20.
When the temperature of the showerpipe reaches 35 degrees Celsius, it is assumed the hot water is running.
The software then allows a standard 3 minutes (adaptable via OpenHAB) for the hot water to run. It then activates the valve via an L9110 H bridge and the water gets closed off. The hot water will remain closed off for 3 minutes, before the procedure starts allover again.

In the comments above, I mentioned the problem of how to prevent that the one using the shower would just turn off the cold water, get out and then leave the hot water tap open. That was circumvented in the easiest way: thermostat fawcetts.

The reason I needed an H-bridge to switch the valve, rather than say a MOSFET or relay, is because the valve is a latched pulse valve. It needs a short pulse to open and it needs a short pulse of reversed polarity to close. The advantage is that it doesn’t need any energy to stay in closed or open position.

The circuit can work on its own, but openHAB is used as interface: mainly to set the allowed showertime.

the hardware is sufficient to switch 2 valves, but program currently supports 1 valve

Previously I did receive some comments that device to limit a teenagers showertime was educationally wrong an that a conversation about the subject would be better. Maybe, but I am making it for someone else, and I guess that when you have a teenage daughter you can have all the conversation you want but in the end you just want it to work :wink:

Anyway, thank you all for your earlier input, till now the device is working very well

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hi there, this shower timer is probably what you need

https://www.youtube.com/watch?v=AJoaej6kNBo

I hope it helps you
cheers

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It was several years ago but my house has two electric water heaters. It was a lower tech solution but I used a smaller water heater supplying the kids bathroom. If they stayed in the shower too long the hot water would run out and it would take a bit to recover. If memory serves it seems like my son figured out that he could reduce the flow and still take a pretty long shower.

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