A softener in a cold room can crack from a single hard freeze. Water left in the control valve, the bypass plumbing, or the drain line expands as it freezes, and the damage often shows up only when the weather warms. The useful question is which protection steps you can take yourself with basic tools, and which ones should go to a licensed electrician or plumber.
Find out where the cold actually gets in
Before you buy anything, check the room on a cold night. A cheap min/max thermometer placed near the valve head and again near the floor will show you the lowest temperature the unit sees. Then look for the source of the cold: an exterior wall, a garage door seal, a crawlspace vent, or a window someone left cracked. Note whether the water supply line or the drain line runs along an outside wall, since that is where freezing usually starts.
What you can do yourself
Sealing gaps and insulating pipes are reasonable weekend tasks. Close drafts around wall penetrations with foam sealant, block an unneeded vent if the building code and your local rules allow it, and wrap exposed supply, bypass, and drain pipe with foam pipe insulation. Keep the wrap off the control head and display so you can still read it, and leave the brine tank lid and salt area clear so you can add salt and see the level.
Do not box the unit in or cover it with blankets, since that traps moisture and blocks access. If you use a space heater in the room, choose one with automatic shutoff, set it on a hard floor, and keep it well clear of the cabinet, cords, and anything flammable.
What to hire out
Heat tape or a thermostat-controlled heater needs a dedicated outlet, usually with ground-fault protection. Any new circuit or wiring belongs to a licensed electrician. Ask the electrician to confirm the tape is listed for use on the plastic plumbing in your install, to label the outlet, and to check that it is not on a shared circuit that trips when a freezer or other compressor starts.
If the supply or drain line has to be rerouted away from an exterior wall, a plumber should do that work. Follow the manufacturer's instructions for the bypass and drain line exactly, and ask the plumber to confirm that any new run slopes properly and has no low point where water can sit and freeze.
Questions to ask before you pay
Ask whether the room you have is the one the installer recommended, and whether the install quote includes insulation or heat tape. Ask what the warranty says about freeze damage and what proof the company wants that the unit was protected, such as photos of the insulation or a record of the thermostat setting. Ask who services the heater and how often its cord and thermostat should be inspected. Keep those answers with your install paperwork.
Run a check before the first hard freeze
Each year, before the first cold snap, walk the room with a flashlight. Look for cracked or slipped insulation, a heat tape indicator that shows no power, a thermostat set to the wrong point, a loose cord, and any new gap where cold air reaches the pipes. Confirm the display reads normally. If you find water on the floor near the valve or the bypass, shut the water supply off at the main and call a plumber before you do anything else.