Many O'Fallon homes keep their water treatment equipment in places that were never meant to be cold. A softener in an attached garage, a sediment filter on an exterior wall near the meter, or a pressure tank in an unheated crawlspace can all be exposed when a hard freeze arrives. Water expands as it freezes, so a small amount of ice inside a plastic housing, bowl, or valve body can crack it. The damage often shows up later, when the thaw lets water seep out.
Find Every Piece That Sees Cold Air
Start by walking the path from where the water enters the house to the first fixture. Note each piece of equipment and whether its location is heated, partly heated, or open to outside air. Common spots include:
- Garages, especially those with a door that stays open or a wall shared with the outdoors
- Crawlspaces and unfinished basement corners near exterior walls
- Well houses, pump pits, and small sheds at the wellhead
- Cabinets under a sink on an outside wall
If a unit sits in one of these spaces, it is a candidate for cold damage even if the rest of the house stays comfortable.
Check the Heat Source Near the Equipment
Equipment that depends on a heat source, such as a furnace duct or a utility room register, needs that source to keep working during a cold night. Look for these issues before the forecast turns:
- A closed or blocked supply register in the room with the water equipment
- Gaps around the pipe penetration where the supply line enters the house
- Missing or compressed insulation on lines or the pressure tank
- A garage door or exterior door that lets a steady draft across the unit
Small fixes such as opening a door to an interior room, sealing a visible gap with foam, or adding insulation around a line are often enough. If a space is still too cold after these steps, a heat tape or a small heater may be an option, but any heating device needs to be installed and used according to its manufacturer's instructions and local electrical rules. Never use an open flame near plastic housings or water lines.
Look at Softeners and Brine Tanks
Water softeners have two parts that matter in winter: the resin tank and the brine tank. The brine tank holds water and salt, and a cold room can slow dissolving and make a regeneration cycle less predictable. Make sure the brine tank is covered and sits in a space that stays above freezing. Keep salt bags away from exterior doors, since moisture plus cold can cause clumping.
If your softener is in a garage, check whether the control head or drain line runs along an outside wall. A drain line that freezes can back up water into the tank, and a stalled cycle can leave the unit in an odd state until someone looks at it.
Check Well Equipment Without Going Into Danger
For private wells in the St. Charles County area, the pressure tank, pump controls, and any treatment units near the wellhead matter most. Look inside the well house or enclosure only if it is safe to do so. Confirm the enclosure door closes fully, that vent screens are clear of ice, and that wiring is dry. Do not work on a pump or electrical panel while standing in water. If a breaker trips, or if you see frost, moisture, or a smell of burning on electrical parts, shut the power off at the breaker and call a licensed professional rather than trying to restart it yourself.
After a Freeze: What to Look For
Equipment can be damaged even when no water is visibly leaking during the cold. Once temperatures rise again, check each unit:
- Look for hairline cracks, bulges, or white stress marks on housings, bowls, and valve bodies.
- Check under sinks and around the equipment for damp spots, drips, or pooled water.
- Run a fixture for a short time and watch for changes in flow, sputtering, or unusual noise.
- Confirm the bypass valve is still in a working position so the house does not lose water if a unit must be isolated.
- Note any unit that looks different from before the cold, and write down the date and location.
If you find water on the floor, shut off the supply at the main valve first, then move any electrical cords or outlets away from the wet area. A cracked housing can release a surprising amount of water quickly, and the cleanup and any repairs should be handled before you restore water to that line.
When to Test the Water
A freeze that split a line or a housing can change the water that reaches your taps, especially if pressure dropped and air or dirt entered the system. If you suspect that happened, consider a basic test. The MO State Public Health Lab offers low-cost or free testing for coliform bacteria, E. coli, and iron-related bacteria, and a private well owner can contact the lab about sampling. Collect the sample from a tap as the lab instructs, and record the date and conditions so the result is easy to compare later.
A Simple Winter Routine
Before each cold season, walk the list once: identify equipment, check the room temperature around it, seal drafts, cover salt and brine tanks, clear well house vents, and confirm the bypass valves work. Write the list on a card and keep it near the main shutoff. A ten-minute check before a freeze is far easier than an emergency in the middle of the night.