What to Do If Your Heat Goes Out During a Cold Snap: Houston Homeowner Emergency HVAC Guide

Houston’s Cold Snaps Don’t Happen Often — But When They Do, They Hit Hard

Houston may not have months of winter, but when cold snaps hit, they hit fast. Temperatures can drop 30 degrees in a matter of hours. Homeowners turn on heaters that haven’t run in months. Heat pumps struggle to keep up. Gas furnaces finally cycle on after long periods of inactivity.

And occasionally, the system just refuses to turn on at all.

Whether your home suddenly feels cold, your heater won’t respond, or the system is blowing cold air, this guide walks you through the exact steps Houston homeowners should take when the heat goes out.

Some issues are simple fixes. Others require immediate professional help.

Here’s how to stay warm, safe, and prepared — without panic.

1. Check Your Thermostat First

A large percentage of “heat not working” calls come from thermostat issues, not HVAC failures. Before assuming the worst, check:

• The thermostat is set to HEAT, not COOL

• The target temperature is 3–5 degrees above the room temperature

• The system hasn’t accidentally been turned OFF

• The batteries are not dead

• The thermostat didn’t reset after a brief power outage

If you recently installed a new thermostat or made changes, the wiring or configuration may not match your system type. Heat pumps, electric heat, and gas furnaces require specific thermostat settings.

2. Make Sure Your Breakers Haven’t Tripped

Cold snaps often coincide with higher energy usage, holiday lights, and increased appliance load. This can trip breakers.

Check your breaker panel for:

• HVAC or “air handler” breakers in the OFF position

• Outdoor unit breaker tripped

• Furnace breaker tripped

If a breaker trips repeatedly, do not force it back on. That indicates an electrical issue that needs immediate professional attention.

3. Check the Air Filter

A clogged filter can restrict airflow so severely that the system overheats and shuts down as a safety measure. In some systems, this prevents the heat from turning on completely.

Replace your filter if it is:

• Grey or dirty

• Covered in dust

• Sagging

• More than 45–60 days old

Many Houston homeowners forget to change filters during fall, and heaters struggle once turned on.

4. Verify the Outdoor Unit (Heat Pumps Only)

If your heat pump is blowing cold air, failing to keep up, or not running at all, the issue could be outside.

Check for:

• Ice buildup covering the entire outdoor unit

• Leaves or debris blocking airflow

• Standing water around the unit

• A tripped outdoor disconnect switch

Some frost is normal during cold weather, but heavy ice or a frozen unit prevents heating.

5. Check for Gas Supply Issues (Gas Furnaces)

If you have a gas furnace — and no heat — the issue may be the gas supply.

Check that:

• Your gas valve is in the ON position

• Other gas appliances (like the stove) still work

• You do not smell gas anywhere in the home

If you smell rotten eggs or suspect a gas leak, evacuate and call the gas company immediately before calling an HVAC technician.

6. Inspect the Furnace Light (Gas Furnaces)

Modern furnaces have an indicator light that helps identify system status.

Look for:

• Solid green light: normal

• Blinking green: startup

• Red or amber flashing light: error code

• No lights at all: furnace not receiving power

If you see an error pattern, turn the furnace off and back on. If it repeats, the system needs professional diagnostic support.

7. Listen for Unusual Sounds

If your heater won’t start or cycles repeatedly, take note of unusual noises including:

• Clicking

• Grinding

• Buzzing

• Squealing

• Loud humming

These noises often indicate failing components such as motors, igniters, or capacitors.

8. Try Resetting the System

Many modern HVAC systems benefit from a power cycle.

To reset safely:

• Turn off the thermostat.

• Turn off the HVAC breaker.

• Wait 60 seconds.

• Turn the breaker back on.

• Wait 5 minutes before turning the thermostat back to HEAT.

If the system restarts and then shuts back down, do not repeat the process. This is a sign of a deeper issue.

9. Understand What Heat Pumps Can and Cannot Do in Cold Weather

Heat pumps struggle once temperatures dip into the low 30s. That does not mean the system is broken.

During a cold snap, it is normal for a heat pump to:

• Run longer

• Produce cooler air at the vents (but still warm the home gradually)

• Switch into auxiliary heat mode

• Defrost periodically

If the auxiliary heat is not working, the home will not warm properly — and that requires service.

10. Know When It’s Time to Call for Emergency HVAC Service

Certain issues require immediate professional help, especially during a cold snap.

Call Velocity Air A/C & Heating if:

• Your system is blowing cold air with no heat

• The heat won’t turn on at all

• You smell burning, electrical odors, or melting

• Your heat pump is frozen solid

• Your furnace cycles on then immediately shuts off

• Breakers trip repeatedly

• You smell sulfur or suspect a gas leak

• Your home temperature continues dropping despite the system running

Cold snaps can be dangerous for infants, elderly family members, or those with medical conditions. If your home cannot maintain safe temperature, call for emergency service.

11. Safe Ways to Stay Warm While Waiting for Help

If your heat is out and you’re waiting for a technician, there are safe ways to stay warm — and unsafe ones.

Safe Options

• Space heaters placed on flat, stable surfaces

• Extra blankets or layers

• Opening blinds during sunny hours

• Closing blinds at night

• Using the oven briefly (not as a heat source)

• Keeping doors to unused rooms closed

Unsafe Options

• Using ovens or stoves as heat

• Bringing outdoor heaters indoors

• Using gas-powered generators indoors or in garages

• Using portable heaters near bedding or furniture

Staying warm safely is always the priority.

12. Prevent Future Cold Snap Emergencies

Houston heaters fail during cold snaps primarily because they sit unused for so long. The best way to avoid last-minute failures is proactive care.

Preventive steps include:

• Scheduling a fall tune-up

• Replacing filters regularly

• Checking heat strips before the first cold front

• Clearing debris around the outdoor unit

• Ensuring vents are open and unblocked

• Testing your heat early in the season

Most emergency cold-snap calls could have been prevented with a pre-winter inspection.

Remember:

Heat outages during a Houston cold snap can be stressful, but many issues have simple causes you can check before calling for service. If troubleshooting doesn’t solve the problem, or you notice signs of electrical issues, gas problems, or unsafe operation, turn off the system and schedule a visit from a licensed technician. Proactive maintenance and early-season testing are the best ways to avoid last-minute emergencies.

Final Thought:

At Velocity Air A/C & Heating, if you are having trouble with your HVAC system, our team is here to help. Whether you need routine maintenance, quick repairs, or a full system replacement, we will keep your HVAC running efficiently and safely, so your home stays comfortable no matter the Texas weather. We provide expert Houston HVAC repair services, Houston HVAC installation services, and Houston HVAC preventive maintenance to keep your system running smoothly and efficiently all season long. Velocity Air A/C & Heating is proud to provide Houston HVAC services, including maintenance, emergency repair, and installation, to the Greater Houston Area.

– Your friends at Velocity Air A/C & Heating