Our internet has now been down for two days while we switch broadband providers, and alongside the frustration of trying to work with patchy mobile coverage, it has been astonishing to discover just how much of our supposedly smart home depends on being able to contact something somewhere on the internet. Our local networks are up and running, the electricity is on and the devices are still sitting exactly where they were before pretending to be doing something, yet various things have largely stopped responding through their usual controls, including something as basic as turning certain lights on and off. Our lamps, for example, are set to turn on 45 minutes before sunset. They're not turning on at all. Watching a light become less useful because it cannot communicate with a distant server does make you reconsider what we actually mean by smart.

That got me thinking about the more substantial equipment we are increasingly connecting to our homes, particularly heat pumps, batteries, solar PV systems and EV chargers, because I would be interested to know how much control everyone actually retains when their broadband disappears. With our own experience, the dependence on an internet connection has become apparent through everyday inconvenience, but what would happen if you needed to change your heating, get a tank of hot water ready or charge the car for an unexpected journey, and the app you normally use could no longer communicate with the equipment?

For those with heat pumps, what can you do directly from the controller in your house when there is no internet connection, and have you actually had to use it under those circumstances? Can you turn the heating on or off, change the temperature and request a hot water boost, and can you override a schedule that was originally created through an app? I am particularly curious about where those schedules actually live too, whether the heat pump remembers and follows them independently, whether you can edit them locally and whether an instruction previously sent through an app leaves you hunting through controller menus to work out how to change it.

I would also love to hear the same from people with batteries, especially where charging and discharging are managed around electricity prices or an external optimisation service, because there are several different things that could matter during an outage. Does your battery carry on following its existing settings, can you change charging times or the minimum charge you want to keep from controls available at home, and what happens to any arrangements that normally depend on receiving fresh instructions over the internet? With solar PV, I would also be interested to hear whether losing connectivity simply leaves a gap in your monitoring or affects any of the controls you normally use to manage the wider system. 

EV charging raises yet another set of practical questions, particularly if your usual routine involves an app, a scheduled charging window or instructions from your electricity supplier. If the internet goes down and you suddenly need the car charged, can you walk outside, press a button and get it charging, or do you need to find another way to override the existing arrangements? Where several systems work together, such as a charger using surplus solar or a home energy management system coordinating the heat pump and battery, which parts continue doing their job and which parts lose their ability to respond?

Please share what equipment you have, how you normally control it and what you can still do when the internet is unavailable, particularly if you have experienced an outage and discovered either a useful fallback or an unexpected limitation. I would also be interested to know whether your installer explained any of this at handover, whether everyone in the household knows how to use the local controls and whether restoring the connection gets everything working again without intervention.

After two days of discovering how much administration can sit between a person and a 'smart' light bulb, I am keen to understand how well our renewable systems cope when the internet stops cooperating. The last two days have been alarmingly revealing.