How it works
A switch, in your board, that knows when to wait.
There is no mystery in this product and we would rather explain it than sell it. Here is the whole mechanism, including the parts where it is estimating rather than measuring.
Where it goes
One location, one certificate
All of the work is inside your distribution board. A registered person isolates the board, fits the controller on the DIN rail in line with the geyser circuit, clips a current sensor around the main incomer, closes up and issues a certificate of compliance for the work under SANS 10142-1.
Nothing is done to your geyser, its thermostat, its element or its plumbing. Nobody needs to get into your roof. It takes twenty to thirty minutes.
A typical domestic board. The controller occupies the DIN modules shown; the rest of your board is untouched.
The mechanism
What it is actually doing
The controller measures the circuit it controls
It sits on the DIN rail in your distribution board, in line with the circuit that feeds your geyser. It measures the current and voltage on that circuit, which tells it exactly when your element is drawing power and how much energy your water heating is using. It does not measure the rest of your house, and it does not measure water temperature — no probe goes anywhere near your tank.
It infers the state of your tank from the thermostat
Your geyser's thermostat is a switch in series with the element. When the water is below the temperature it is set to, the thermostat is closed and the element draws current. When the water is up to temperature, it opens and the current stops. The controller reads that pattern — how often the element calls for heat, and for how long — and builds a picture of how much hot water you have. It is an inference, not a measurement, and the app says so.
During a peak window it opens the circuit
A municipal peak window is a few hours in the morning and evening when demand on the network is at its highest. During one, the controller holds the circuit open so your geyser does not heat. Your tank is insulated; it holds the water it already heated. When the window ends, the circuit closes and normal heating resumes.
Your floor overrides the window
You set a level your hot water should not drop below. If the controller's picture of your tank says you are approaching that level during a window, it heats anyway. The peak window is a preference. The floor is a rule.
Boost overrides everything you can override
Press boost and the circuit closes immediately and heats for as long as you asked. The one exception is a live grid event, where the boost is queued and starts the moment the event ends — and the app tells you the time it will start rather than leaving you to wonder.
With solar, it heats when you are exporting
A second current sensor on your main incomer tells the controller how much power the house is importing or exporting. When your panels are producing more than the house is using, the controller can put that surplus into the geyser instead of sending it to the grid. This is the work the controller does that a simple timer cannot.
The app
It answers one question first: will I have hot water?
Not kilowatts. Not a dial. The state of your geyser in plain words, an estimate of the hot water you have, and a boost button that tells you the truth about when it will start.
- Every grid event is shown before it starts, while it runs, and afterwards with what actually happened.
- The app installs to your home screen from the browser. There is nothing to download from an app store.
- Alerts reach you on WhatsApp, or as a notification, or by SMS — whichever you choose.
Every state the app can show you, and there are no others
The same words are used in the app, in alerts and by support, so that what you are told on the phone matches what you are looking at.
When things go wrong
The four failures, and what each one does to your hot water
The power goes off in your area
The geyser is off because the power is off, like everything else. The controller reports the outage when supply returns, and the app shows it as a power outage in your area — not as a grid event, and not as a fault. When supply comes back, heating resumes on its own.
The controller loses signal
It keeps running the schedule it already has. Every instruction we send carries a time after which it stops being valid, so a stale instruction expires rather than persisting. If the controller has heard nothing from us for longer than that, it returns to ordinary, uncontrolled heating. The design rule is that you should never be worse off than you would have been with an ordinary geyser.
The controller fails
The switching contact is chosen so that a failed or unpowered controller leaves the geyser circuit able to heat rather than held open. A fault is reported in the app as a fault, in plain words, with what we are doing about it.
You want out
Withdraw in the app, in settings, without giving a reason and without a phone call. We arrange for the controller to be removed or permanently disabled, at no cost to you.
Still deciding?
The next page is the one worth reading — what the controller does, and the list of things it is not able to do even if we wanted it to.