Furnaces
Furnace Installation, Repair & Replacement
Dependable heating when you need it most.
The short answer
Green Core Heating & Air installs, repairs, and maintains gas furnaces for homes across Sonoma and Marin counties. We fix no-heat calls, replace aging furnaces with right-sized high-efficiency models, and help homeowners compare a furnace with an all-electric heat pump when it's time to replace.
Overview
Furnaces in Sonoma and Marin
Green Core Heating & Air repairs, maintains, and replaces gas furnaces for homes in Petaluma, Santa Rosa, Novato, San Rafael, and across Sonoma and Marin counties. Whether your furnace won't light on a cold morning or it has simply reached the end of its life, we'll find the real problem and give you honest options.
When it's time to replace, we'll show you a high-efficiency furnace and an all-electric heat pump side by side, with written pricing for each, so you can choose what's right for your home and budget.
Benefits
Why homeowners choose this.
Proper sizing
Right-sized systems run longer, quieter, and more efficiently.
Airflow first
We address airflow issues that cause short cycling and hot/cold spots.
Efficient upgrades
High-efficiency furnaces and heat pump options when it's time to replace.
Long-term reliability
Installed right the first time, designed to last.
Furnace repair
The most common furnace calls are no heat, a furnace that starts and then shuts off, ignition or flame sensor problems, a blower that won't run, and strange noises or smells. Many of these come down to a dirty flame sensor, a failed igniter, a bad inducer or blower motor, or a clogged filter.
We test the safety controls and combustion, explain what we found, and give you a written price before any repair.
Furnace installation and replacement
If your furnace is 15 to 20 years old, needs a major repair, or can't keep the house comfortable, replacement usually makes sense. We size the new furnace with a load calculation, check the ducts and venting, and install to code with a permit.
It's also the right moment to consider a heat pump, which replaces the furnace and adds cooling, and often qualifies for rebates. We'll price both options so you can decide.
- High-efficiency furnace replacements
- Heat pump options priced side by side
- Permits and inspection handled
Furnace maintenance
A fall tune-up before the cold sets in keeps a furnace safe and reliable. We clean and check the burners, igniter, and flame sensor, test safety and limit switches, inspect the heat exchanger and venting, check the blower, and replace the filter.
Replacing a furnace: your two main options
| New gas furnace | Heat pump | |
|---|---|---|
| Heating | Yes | Yes |
| Cooling | Needs a separate AC | Built in |
| Fuel | Natural gas | Electric |
| Rebates | Rarely | Often available |
| Electrical work | Usually none | Sometimes a panel upgrade |
Our work
Recent projects in Sonoma and Marin
Real Green Core jobs for homeowners in Sonoma and Marin, with photos from the job site.
July 2026
Heat pump replaces an attic gas furnace in Petaluma
We removed an aging gas furnace from the attic and installed a high-efficiency Carrier heat pump, sized for the home, so it now heats and cools on one all-electric system.
See the job photosJuly 2026
Furnace and AC tune-up with duct repair in Sonoma
We serviced an American Standard furnace and outdoor unit, tested the electrical components, cleaned the condenser coil, and replaced damaged duct sections.
See the job photos
FAQ
Furnaces questions, answered
Why won't my furnace turn on?
Common causes include a tripped breaker or switch, a dirty filter, a failed igniter, a dirty flame sensor, or a thermostat problem. If basic checks don't fix it, call us for a repair.
Why does my furnace turn on and then shut off?
This short cycling is often caused by a dirty flame sensor, an overheating furnace from a clogged filter or blocked vents, or an oversized system. We'll find the cause.
Should I repair or replace my furnace?
If your furnace is over about 15 years old and needs a major repair, replacement is usually the better investment. Newer furnaces are almost always worth repairing.
Should I replace my furnace with a heat pump?
Often, yes. A heat pump heats and cools, runs on electricity, and may qualify for rebates. If your home needs a large electrical upgrade, a new furnace may still be the better short-term choice. We'll price both.
How often should a furnace be serviced?
Once a year, ideally in the fall before heating season.
How long does a furnace last?
Typically 15 to 20 years with regular maintenance.
Ready to talk furnaces?
Share a few details about your home and we'll reach out with clear, honest options.