Common Heating Problems in Winter and How to Fix Them

Serving Solano & Contra Costa Counties, CA

Introduction: Winter in the Bay Area Demands a Reliable Heating System

When winter arrives in Solano and Contra Costa Counties, temperatures drop fast—and that’s usually when
heating systems decide to act up. Whether you’re dealing with weak airflow, strange noises, or a furnace
that won’t turn on at all, winter is the most common time for heating problems to appear.

The good news? Many issues are preventable with basic maintenance. Others can be diagnosed quickly with a
little troubleshooting. And when in doubt, Dependable Heating & Air Conditioning is here to help
homeowners stay warm, safe, and comfortable all season long.

What Are the Most Common Heating Problems in Winter?

Below are the winter heating issues we see most often in homes across Solano and Contra Costa Counties —
along with what typically causes them.

1. Furnace Not Turning On

This is one of the most common winter calls we receive. Several things can cause a furnace to stop powering on:

Thermostat is set incorrectly or malfunctioning
Tripped breaker or blown fuse
Dirty or clogged furnace filter
Failed ignitor or flame sensor
Loose wiring
Safety switch triggered (often due to overheating)

Quick homeowner checks:

Make sure the thermostat is set to HEAT and above room temperature.
Replace the air filter.
Check your electrical panel for tripped breakers.
Make sure the furnace door is securely closed—most units have a safety switch.

If none of the above help, a technician should inspect the ignitor, sensor, or control board.

2. Insufficient Heat or Cold Air Blowing

Your system is running but the air coming out isn’t warm enough—or worse, it’s cold.

Common causes:

Dirty air filter restricting airflow
Duct leaks causing warm air to escape
Incorrect thermostat settings
Blower motor issues
Low gas supply
Blocked burner or ignition issues

Homeowner solutions:

Replace the filter.
Check vents to ensure they’re open and unobstructed.
Verify thermostat is on AUTO, not ON (ON runs the fan continuously).

If heat is still weak, diagnostic testing is needed.

3. Uneven Heating Throughout the Home

One room feels warm while another stays cold. This is extremely common in older homes or homes with long duct runs.

Typical causes:

Blocked or closed vents
Incorrectly sized HVAC system
Ductwork leaks or poor design
Poor insulation
Failing blower or poor airflow

Improvement options:

Open or adjust vents.
Seal or redesign ductwork.
Improve insulation in attics or crawlspaces.
Add a zoning system for better temperature control.

4. Furnace Short Cycling (Turning On and Off Rapidly)

Short cycling is more than annoying—it’s a sign something is wrong.

Causes:

Overheating furnace
Dirty filter
Faulty thermostat
Improperly sized furnace
Blocked exhaust or venting

Why it matters: Short cycling increases wear, spikes your energy use, and shortens your furnace’s lifespan.

5. Strange Noises Coming From the Furnace

Unusual noises are often the furnace’s early warning system.

Common sounds and their meaning:

Banging or booming: Dirty burners or delayed ignition
Squealing: Worn belts or motor issues
Rattling: Loose panels or components
Grinding: Failing motor bearings
Whistling: Airflow restriction or duct leaks

If your furnace is making anything other than a low hum, it’s worth getting inspected.

6. Rising Energy Bills During Winter

If your heating bill suddenly spikes, your system may be working harder than it should.

Possible reasons:

Dirty filters
Leaky ducts
Poor insulation
Aging furnace
Thermostat inefficiency
Frequent on/off cycling
Equipment struggling due to old age

A winter tune-up can pinpoint the exact cause and restore efficiency.

How Do You Fix Common Winter Heating Problems?

Most heating issues can be narrowed down to a handful of basic problems. Here’s what you can safely do—and
when you should bring in a professional.

DIY Troubleshooting Steps Homeowners Can Safely Try

1. Replace or Clean the Furnace Filter

The number one reason for winter heating problems is a clogged filter. Replace your filter every
1–3 months during winter.

2. Check and Adjust the Thermostat

Ensure it’s:

Set to HEAT
Above room temperature
On AUTO instead of ON

If it still misbehaves, the thermostat may be failing.

3. Inspect and Open All Vents and Registers

Blocked vents cause uneven heat and pressure issues. Make sure furniture, rugs, and curtains aren’t
blocking airflow.

4. Reset a Tripped Circuit Breaker

If the furnace lost power due to a surge, a simple breaker reset may restore operation.

5. Check for Error Codes

Newer furnaces often have LED lights or digital displays that show codes. A blinking light or code can
help technicians diagnose the issue faster.

When to Call a Professional HVAC Technician

Certain issues should never be DIY’d:

Electrical problems
Gas leaks or gas supply issues
Ignitor or flame sensor failure
Blower motor or capacitor issues
Heat exchanger cracks
Repeated short cycling
Furnace overheating

These issues require tools, testing equipment, and training to diagnose safely. If you smell gas, hear loud
bangs, or your system repeatedly shuts down—turn off the furnace and call a technician immediately.

Why Is My Furnace Running but Not Heating?

If the blower is running but no heat is coming out, several issues could be to blame.

Possible causes include:

Dirty burners
Faulty ignitor
Thermostat set incorrectly
Airflow blockages
Clogged filter
Tripped safety switch
Low gas supply

Homeowners can check filters, thermostat settings, and vents first. If the ignitor or burners are the issue,
it’s time to call a professional.

Why Is My Heater Blowing Cold Air Only in the Morning?

This is especially common in heat pump and gas furnace systems and is often tied to how your home and system
recover from colder overnight temperatures.

Possible reasons:

Morning temperature setbacks on the thermostat
Heat pump defrost cycles
Duct leaks that lose heat before it reaches certain rooms
Thermostat issues or incorrect settings
Furnace not fully warming up due to a weak ignitor

If the issue continues daily, the system may require inspection and fine-tuning by an HVAC technician.

How Often Should I Service My Heating System?

Furnaces and heat pumps should be professionally serviced once per year, ideally in fall
before heavy winter use.

Benefits of annual maintenance:

Lower heating bills
Longer system lifespan
Fewer emergency repairs
Better airflow and comfort
Improved indoor air quality
Safety assurance for gas heating systems

How Do I Prevent Heating Problems in Winter?

Follow this maintenance checklist to prevent many common issues:

Change furnace filters regularly.
Clear debris from around the furnace.
Keep vents and registers open.
Check ducts for visible gaps.
Schedule annual tune-ups.
Seal drafty windows and doors.
Improve insulation where needed.

These steps help prevent the majority of heating problems we see each winter in Solano and Contra Costa
Counties.

Dependable Heating & Air Conditioning: Your Local Winter Comfort Experts

If you’re experiencing any heating issues—big or small—Dependable Heating & Air Conditioning is ready to help.

We proudly serve Solano and Contra Costa Counties, including:
Vacaville, Fairfield, Dixon, Vallejo, Benicia, Suisun City, Concord, Walnut Creek, Pleasant Hill,
Martinez, and surrounding areas.

Our services include:

Furnace repair
Heating system diagnostics
Heat pump repair
Furnace replacement & installation
Annual heating maintenance
Emergency winter heating service

Our technicians are trained, certified, and committed to keeping your home safe and warm all winter long.

Schedule Your Heating Service Today

Whether your system is blowing cold air, shutting off unexpectedly, or simply not keeping up with winter
weather, we can help.

Call Dependable Heating & Air Conditioning today for fast, reliable heating repair or maintenance.