Please tell me why I shouldn’t try this…
Can I automate my shower using the Sonoff Smart Water Valve
Obviously, I’ll need adaptors to convert between the different pipe sizes.
Thaughts welcome
Can you? Yes. But… why?
That would give you a simple on/off. And I assume it’s a motorized valve inside, so it’s going to move slowly between “on” and “off.” During that time the shower will get too hot or too cold. As with most shower head shut-off valves, when it comes back on, again, it’ll be too hot or too cold.
The unit and the adapters to fit it to a shower nozzle will take up a lot of space, putting the shower head pretty low.
Those are the first things which came to mind. Without knowing what the use case is, there may be more. Like, if you plan to leave the existing shower valve(s) open all the time, and rely on this to stop the flow whenever it’s not in use, there may be issues there.
Depending upon location’s age and construction, you could end up with hot water where you have cold water - like, in the toilets.
These valves are they rated for hot water even?
If not they will fail always… matter of time
In the first rush to launch digital showers, the early models had simple ‘on/off’ water valves and stepper motors to control a standard thermostatic mixer valve. I purchased a top of the range WITHELD digital shower, and when (all too soon) the O-rings began to fail on the inlet adapters, I went back to them for spares, only to discover that the model had been withdrawn and there were neither spares nor support, to the point of seemingly disowning the model.
Apparently there had been a significant ‘issue’ involving a customer, a shower, and some very hot water.
All showers have to address the problem of start-up and shut-down, to ensure that dispensed water temperature is within acceptable limits at all times, and also to warn users about re-starting a shower that may contain a slug of over-temperature water within the internal pipework.
Depending on the heating - internal electrical, external hot-cold feed, digital showers will include a start-up and shut-down sequence to bring the end feed water temperature up from cold, and back down as required.
Non-digital showers with internal electric heating elements will also often have a start-up and shut-down sequence, as well as over-heat protection and physical expansion venting.
Simply starting a basic water feed from an externally controlled valve circumvents all the protection and interlock devices included in the shower device itself.
Then there is the issue of remote start of any device that is not directly under immediate visual supervision. Even the fancy remote control included with the (long gone) digital shower model had a big warning, saying much along the lines that you can start your shower remotely from outside the shower location, but you should first ensure that doing so will not cause an issue (flooding comes to mind).
I never used the remote control. Turn on the bath-taps without actually being in the bathroom? What could possibly go wrong!
Googled a random zigbee water valve:
These things are mounted on top of standard valves that work with hot water.
Just remember to keep these accessible at all times if they do fail so you can still control it manually.
Thanks @CaptTom
The hot and cold water will have been mixed before it gets to the Sonoff valve so I think it should be the correct tempurature - once the hot water reaches the mixer.
My shower head is on a hose (I’m in the UK) so the Sonoff valve would go between the mixer outlet and the hose.
Mmmm. not sure about this bit. I would want to leave the existing valve open.
Which means you’re not sure that it could not happen. [wink]
Hot water pressure typically is a function of cold water pressure, whether from the street pressure or fed by gravity tanks. Where the valve (or valveS) would be installed in the system matters. I also don’t know whether you’re talking about an apartment or single family home. Lots of variables not yet defined.
Ah. . (edit) just saw this:
That’s what I was thinking of. . .
In that case, you’d need to insure that both the hot and cold water lines have their own check valves installed in-line to insure the water in each only flows one way. I had residents in an apartment building put a valve before the shower head so they could leave the shower body set (to retain a favored temperature w/o having to adjust it). Surrounding apartments would report they got hot water in their toilets and in the cold water lines. While the pressure was pretty much equal between hot and cold lines, the temperature difference would have the hot water be drawn into the cold when other locations on the same supply would be utilized (through the shower body valves left open), instead of the other way around.
I looked at lots of different valves/flow meters but came across this and it works fine with HA using the Theengs gateway addon:
I’m in the UK using a standard thermostatic mixer valve
EDIT: Sorry, I see you want to control the shower not just monitor it
Thanks everyone. I think I’ll park the idea for now.
Look at the post by @Biscuit below the one of mine you’re replying to.
The problem is, if you shut off the water after the mixing valve(s) there can be a rush of hot or cold when you open it back up. In an old two-valve (one hot, one cold) water can flow in one and out the other. Even more modern mixing valves can’t regulate the temperature if the water isn’t flowing.
To me this is just a minor annoyance. They don’t even sell water heaters which can reach scalding temperatures any more. And I always stand to one side when I turn a manual shutoff valve back on, to give it a second to adjust. Personally, I wouldn’t worry about it, but I know it bothers a lot of people, and could actually be dangerous if your water is hot enough.
Those irrigation valves are pretty cheap built with plastic parts inside. Tey break pretty easily. Durability is less relevant for irrigation. Either they become too hot, when put in the hot water pipe, or they don’t when put after mixing. And when they don’t get that hot you would need to worry about the Legionella bacteria that may catch hold of a device that wasn’t designed to be used this way.