Most water softeners run on a clock, a meter, or both. Before you commit to a model, ask what happens when the power goes out. The answer decides whether the unit comes back with the right time and settings, whether it starts a regeneration at an awkward hour, or whether it sits idle until someone notices the water has gone hard.
Why the clock matters
Many control heads use a time-of-day setting to decide when regeneration starts. If that setting is lost, the display may flash, the unit may regenerate at the wrong hour, or it may wait for someone to reset it. Metered units still need a clock if you set them to regenerate at a fixed time, so this question applies to them too. A unit that regenerates on demand still needs correct time for its display and logs, and you want those to be right when you check on the system.
What to ask the seller or installer
Get these answers in writing, or confirm them against the product manual before you sign. A verbal estimate is not enough for a question that matters when no one is home.
First, how long do the settings hold without power, and is the memory kept in a way that needs a battery you have to replace? Ask for the figure from the manufacturer's documentation. Second, what does the display show after an outage, and what are the exact steps to reset the time and the regeneration schedule? Third, does regeneration start as soon as power returns, or does it wait for the scheduled time? Fourth, what happens if the outage interrupts a regeneration cycle partway through? Ask whether the unit restarts that cycle on its own or needs a manual start. Fifth, does the control have a manual regeneration button, and where is it on the unit?
Set the schedule before the installer leaves
Have the installer set the time and choose a regeneration hour that fits your household. Pick an hour when the water is seldom used, and write it down. Ask the installer to walk you through the reset steps while they are still on site, and keep the manual where you can find it. The person who will be home when an outage ends may not be the person who signed the paperwork, so the reset steps should be written where that person will see them.
Protect the control from the outlet up
Ask which outlet the unit will use and whether a wall switch can cut its power. An outlet controlled by a switch that someone turns off for another reason is a common way to lose settings without knowing it happened. Confirm with the installer that the outlet is suitable for the unit and that it meets your local electrical requirements. If you are considering a battery backup or surge protection, ask the manufacturer whether it is approved for that control, and whether the backup can run the control through a regeneration cycle. A backup sized for a small electronic device may not carry a motor-driven cycle, so do not assume it does.
Check the answers against a rating
If you are reading a ranking to shortlist companies or models, check whether power-outage handling appears as a criterion. If it does not, the ranking may not tell you what you need to know about this question. The rating methodology page explains which criteria are used and how they are weighted, so you can see whether this topic is covered before you rely on the score.
After any outage
Once power is back, check the display, the time, and the regeneration schedule. If anything looks off, reset it using the steps you wrote down, and confirm the next regeneration will run at the hour you chose. A short check after each outage costs little and catches the problem before the water goes hard.