When winter temperatures plunge, two of the most common (and costly) cold weather problems homeowners face are frozen water pipes and frozen HVAC coils. Both can cause major damage from water leaks and burst pipes to a complete loss of heat right when you need it the most.

The good news? With the right preparation, you can prevent most cold weather HVAC and plumbing emergencies. Below, we share what causes pipes and coils to freeze, early warning signs, and the best steps you can take to keep your home warm and safe all winter long.

Why Pipes and HVAC Coils Freeze

Frozen Pipes

Pipes freeze when water inside them reaches 32 degrees Farenheit (0 degrees Celsius). As the water turns to ice, it expands, putting pressure on the pipe walls. This can lead to cracks or full bursts, often resulting in major flooding and expensive repairs.

Common areas at risk:

  • Unheated basements or crawl spaces
  • Exterior walls
  • Attics
  • Garages
  • Under sinks or near drafty windows

Frozen Coils

Your HVAC system relies on proper airflow and refrigerant levels to maintain the right coil temperatures. In the winter, coils can freeze due to:

  • Dirty air filters
  • Blocked vents
  • Low refrigerant
  • Outdoor unit obstruction (snow or ice buildup)
  • Poor airflow from closed registers

When coils freeze, your system can’t heat effectively. Left unchecked, this can even damage the compressor.

Warning Signs Your Pipes or Coils May Be Freezing

Signs of Imminent Frozen Pipes:

  • Very low water pressure
  • Frost visible on exposed pipes
  • Strange odor from faucets (caused by blocked ventilation)
  • No water at all when you turn on a tap

Signs Your Coils Are Freezing

  • Reduced airflow from vents
  • Home not warming despite system running
  • Visible frost or ice on refrigerant lines
  • Rising energy bills
  • HVAC unit suddenly shutting down

How to Prevent Frozen Pipes

1. Insulate Pipes in Vulnerable Areas

Use foam pipe sleeves or fiberglass insulation around exposed pipes in basements, attics, and crawlspaces. This is one of the most effective, and inexpensive, preventive steps.

2. Keep Indoor Temperatures Consistent

Never let your thermostat dip below 55 degrees Farenheit (even when away from home). Consistent heating prevents pipe temperatures from dropping too low.

3. Allow Faucets to Drip

A slow drip keeps water moving and relieves pressure. This is especially helpful for sinks near exterior walls.

4. Open Cabinet Doors

Opening cabinets under kitchen and bathroom sinks allows warm air to reach the plumbing inside.

5. Seal Drafts

Cold air leaks around windows, doors, or exterior wall penetrations can quickly chill nearby pipes. Weatherstripping and caulking help protect those vulnerable areas.

How to Prevent Frozen Coils

1. Change or Clean Air Filters Regularly

A clogged filter restricts airflow, causing coils to get too cold. Replace filters every one to three months, or more frequently if you have pets or allergies.

2. Keep Vents and Registers Open

Avoid closing too many vents, this disrupts airflow and can lead to coil freeze ups.

3. Clear Snow and Ice From the Outdoor Unit

Make sure your outdoor unit has at least 18 inches of clearance. Gently remove snow around the base and ensure melting ice can drain away.

4. Check Refrigerant Levels

Low refrigerant causes pressure imbalances that lead to freezing. If you suspect a leak, call a technician immediately.

5. Schedule Regular HVAC Maintenance

Professional tune ups keep your system running efficiently and catch early issues before they lead to a frozen coil.

What to Do If Your Pipes or Coils Freeze

Frozen Pipes

  • Turn on faucets to relieve pressure
  • Use a hair dryer or space heater to gently warm the pipe (never use an open flame)
  • If the pipe has burst, shut off your main water supply immediately and call a plumber

Frozen Coils

  • Turn off the HVAC system to prevent damage
  • Switch the thermostat to Fan Only to speed up thawing
  • Clear any snow or ice from the outdoor unit
  • Call an HVAC technician to diagnose underlying issues like airflow problems or refrigerant leaks

Stay Warm, Safe, and Protected This Winter

Frozen pipes or coils could be stressful and expensive but with a few preventive measures and regualar HVAC maintenance, you can greatly reduce the risk.

If you’d like a winter prep inspection or need help with a heating issue, our team at 4 Winds AC and Heating is here to help. Contact us today to schedule service and keep your home running smoothly all season long.