Fixed in two hours without a visit: how an over-the-air firmware update solved a customer’s “0% won’t stick” problem
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Hardware companies like to talk about features. Customers remember how a problem was handled. This is the second half of the Tallinn boiler story, and it is about a bug that was ours, found by a customer's screen recording, and fixed on his device remotely within two hours.
The customer's problem
After correcting his Cheap Mode settings, the customer set the plug's Manual power ratio to 0% as instructed. The app refused to keep it: the value jumped back to 25% on its own. He sent a screen recording and asked the right question: is 0% actually a supported, stable state on my socket, or is this a software issue, a device limitation, or another setting? Without a stable 0% the boiler could keep drawing power outside the three cheap hours, which defeats the purpose.
What we did
The recording let us reproduce it quickly. His plug was running an older firmware that did not accept 0% as a valid Manual level and silently fell back to the lowest level it knew (25%). It was our bug, and we said so. The fix was a firmware update that was already available; we pushed it to his plug over the air, so he did not have to do anything for the update itself. He restarted the app, set 0%, it held, one Deactivate → Activate cycle refreshed the schedule, and he confirmed it was working. Elapsed time from his first email to "now it's working": about two hours, on a Monday morning.
Benefit for the customer
No visit, no return shipment, no waiting for a replacement unit. The plug he already had became the current product by the time he finished his coffee, and he could verify it himself the next day in Statistics. For a device that costs €35 and sits behind a boiler, the ability to be repaired remotely is worth more than any single feature.
Technology used
Over-the-air (OTA) firmware delivery from the GPO backend to individual plugs over Wi-Fi, with the ability to target one device by its ID; app-to-plug state sync so that a rejected value is visible immediately in the app; per-device schedule inspection on our side ("we can check exactly what schedule your plug received").
Improvements and know-how
Three things came out of this. The 0% fix is in the current firmware. The symptom ("Manual mode won't hold 0%") is now covered in the FAQ below. And a process lesson: a 20-second screen recording resolved in minutes what three screenshots could not; we now ask for one as the first step whenever a value "does not stick".
What's next
Remote diagnostics is the direction. The plan is to show the plug's active schedule and firmware version inside the app, so a customer can see the same data we see without writing to us. Our support promise for the plug stays the same: answers in Estonian, English and Russian, from Tallinn, and if a 0% does not hold after an app restart we look at the unit the same day.
FAQ
Do I need to update the plug's firmware myself? Not in the case described here: we pushed the update to the plug over the air, and the customer did nothing for the update itself.
Is 0% a stable Manual state? Yes, on current firmware. If yours jumps back to 25%, restart the app; if it persists, write to us and we will check the unit.
Questions about an existing plug?
Write to shop@gpo-tech.com or call +372 5760 6060 (Mon–Fri 9–17 EET).