It is hard to miss when your furnace stops working. The house feels colder than your thermostat says, it's making a sound it didn't make last winter, or you see an unexpected spike in your monthly heating bills.
Furnaces usually give some warning signs before they stop working. These are the symptoms we hear about most often from DMV homeowners.
Air that never warms up can point to an ignition problem, a gas supply issue, or a thermostat setting. Our guide on why a gas furnace isn't blowing hot air covers the most common causes.
A furnace that lights and then shuts off a few seconds later is often dealing with a dirty flame sensor.
A furnace that turns on and off every few minutes may have restricted airflow, be overheating, or have a thermostat problem.
A furnace that doesn't respond at all may have a power, control board, or ignition issue.
Rooms that stay much colder than others may point to a weak blower or blocked vents.
A fan that never shuts off may be set to "on" through the thermostat, or it may have a faulty control.
Banging, squealing, rattling, or a "boom" when turning on usually means a part is worn, loose, or not igniting cleanly.
Gas burners should burn a steady blue, so a yellow or wavering flame is worth having checked out.
On high-efficiency furnaces, water often points to a clogged condensate drain or a failed condensate pump.
A jump in your bills with no change in how you use your heat can mean the furnace is working harder than it should.
On older furnaces, a pilot that keeps going out usually points to a part that needs attention.
You don't need to diagnose the issue yourself, but there are a few quick items you can check before calling a heating technician. Anything beyond these is a job for one of our experts.
If the furnace still won't heat after running through this checklist, we recommend calling a professional. If you smell gas at any point, stop troubleshooting and leave the home.
Book Your Repair
John C. Flood repairs gas, propane, and electric furnaces throughout the DMV. Our technicians track down the real root of the issue, and we scope every repair to what your system needs.
A gas furnace relies on a short chain of parts working in the right order to light and stay lit. When one of them wears out, such as an igniter, flame sensor, or control board, the whole furnace can stop. Our approach to gas furnace repair begins with identifying that failing component to guarantee a lasting solution.
While older gas units rely on a continuous standing pilot, most modern systems utilize electronic ignition. If a standing pilot fails to remain lit, our technicians can quickly clean or replace the dirty or worn component responsible. For systems with electronic ignition, we will perform a complete diagnostic on the ignition system instead.
In addition to electric furnaces, we service dual fuel systems that combine a primary heat pump with a backup gas furnace. For dual fuel setups, our service covers the control systems that manage transitions between heating sources. If your property relies solely on a heat pump, John C. Flood also offers heat pump repair services.
Proper furnace operation relies on a dependable blower motor to circulate warm air and an effective venting system to safely exhaust combustion byproducts. Our technicians resolve blower malfunctions, clear blocked vent pipes and condensate lines on high-efficiency units, and verify that safety switches function properly to keep your home protected.
Because heating failures often occur outside regular operating hours, our call center is available 24/7. Overnight heating issues are recorded immediately and prioritized for first-available dispatch the following morning. We offer transparent flat-rate pricing seven days a week, with no extra charges for weekend service.
A yearly furnace tune-up before heating season gives our technicians a chance to catch worn parts early and keep your furnace running efficiently. Our Service Partner Program makes it easy to stay on schedule.
For more than 120 years, DMV homeowners have called John C. Flood for their furnace repairs, and every job starts the same way. Here's what happens when you book with us.
Your technician starts by asking what you've noticed and when it started.
We check the furnace in your home, including its safety controls and venting.
You'll get a clear explanation of what's wrong and what we recommend.
We give you the price before any work begins.
Our technician completes the work with care for your home.
We run the furnace through a full heating cycle, clean up, and show you what we did before we leave.
If your furnace is not producing heat, contact a licensed HVAC professional like John C. Flood. Because multiple entities play a role in managing your home heating system, knowing whom to contact can be confusing.
For everything on the furnace side, our team is ready to help. You can book your furnace repair online or give us a call.
A breakdown of responsibilities for your heating system.
Deciding whether to fix or replace your furnace comes down to its age, repair history, and overall efficiency. Our team will always give you an honest assessment.
Efficiency matters too. A furnace's Annual Fuel Utilization Efficiency (AFUE) rating indicates how effectively it converts fuel into warmth for your home. The U.S. Department of Energy notes that older, low-efficiency models perform between 56% and 70% AFUE, whereas modern high-efficiency systems reach up to 98.5%. Whatever your situation, our technician will lay out both options and let you decide, with no pressure either way. If replacement turns out to be the right call, learn more about our furnace installation and replacement services and how to size a new furnace for your home.
Book Your Repair
Because furnaces run on gas or electricity and rely on integrated safety systems, hiring a qualified professional to handle repairs gives you true peace of mind.
Heating needs vary across the DMV. Local winter temperatures, property age, and regional building codes all influence the specific repairs a furnace may require. Our team has served homeowners throughout Northern Virginia, Maryland, and Washington, DC for generations, bringing deep familiarity with the distinct heating setups in every community.
Winter temperatures tend to drop lower the further you move from the urban center. Extended periods of cold increase operational demands on your system, accelerating wear on critical components like igniters, blower motors, and inducer fans.
Housing across the region ranges from historic urban architecture to modern suburban developments. Historic rowhouses in DC, established neighborhoods in Montgomery County, and suburban communities built across Northern Virginia between the 1960s and 1980s present unique heating requirements. Older properties frequently feature replacement systems or legacy standing pilot units that require specialized care.
Permitting regulations for HVAC service vary depending on local jurisdictional guidelines. For instance, residential mechanical permits in Fairfax County govern system installations, major repairs, and fuel conversions, while Loudoun County, Montgomery County, and DC maintain independent permitting requirements. When a permit is required, John C. Flood manages the entire process. Gas service is similarly determined by location, with providers such as Washington Gas servicing portions of DC, Maryland, and Northern Virginia.
"He takes the time to explain the situation and lays out all the options and processes so clearly so I feel comfortable with what he is doing. The company is excellent at sending people in a timely matter."
Bruce B."Knowledgeable, professional, and equally as important, full of integrity. While they presented various options, they did not try to sell me something that I did not need."
John J."Each time, they're very responsive and reasonably priced. He has done excellent work for me. Highly recommend the company and the technician!"
Samantha T.
DMV homeowners have trusted John C. Flood with their furnace repair for generations. Here's what you can count on when you call us.
Our Gold Service Partner plan includes your fall heating inspection and spring A/C inspection, plus plumbing and electrical inspections. Members also save on repairs and replacements all year long.
Ask about the Service Partner Program when you book your furnace repair.
Regular rates 7 days a week. Licensed technicians. Flat-rate pricing.
