Serving Washington, DC, Prince George's County, Montgomery County & Northern Virginia, including Upper Marlboro, Hyattsville, District Heights and Silver Spring.
A furnace can keep heating the house and still have problems worth catching. Poor venting, weak combustion or restricted airflow may not stop the heat altogether, but they can affect how safely and efficiently the system runs. That is why a tune-up matters even when nothing feels obviously wrong.
At Nero's Heating & Air, we look closely at how the furnace is burning, venting and moving heat through the system. We check the parts that affect ignition and combustion, review the readings, and explain anything that is starting to drift before it turns into a bigger winter problem.
| Stat | What it means for your furnace |
|---|---|
| 3 seconds | How long the control board waits to confirm flame before shutting the gas off again. |
| 100 ppm | The flue reading above which a furnace needs attention rather than a note in the file. |
| 9 ppm | The EPA's eight-hour limit for carbon monoxide in the air you actually breathe. |
| 1 year | The service interval nearly every manufacturer's parts warranty is written around. |
A cooling visit is about moving heat out of the house. A heating visit is about making heat inside it, deliberately, with gas. That difference is the whole reason the two visits are not interchangeable, and it is where most of the heating checks sit.
A furnace may vent properly until the house starts pulling air in other directions. We run the exhaust fans and the dryer, close the windows, and check that the furnace can still vent safely while those appliances create negative pressure.
A flame can look normal and still burn incorrectly. We test the exhaust with a combustion analyzer instead of judging the burner by appearance alone, giving us actual readings on how cleanly and efficiently the furnace is burning.
The heat exchanger keeps combustion gases separate from the air circulating through your home. We inspect it for cracks, corrosion and other signs of deterioration that could affect safe furnace operation.
The igniter, flame sensor and safety controls all have to work in the right order for the furnace to start and stay running. We check that sequence from beginning to end so developing ignition problems are easier to catch.
A furnace needs enough surrounding air and space to operate safely. Closets packed with storage, blocked openings or changes made during a basement renovation can affect that airflow, so we check that the furnace still has the clearance and combustion air it needs.
Our maintenance agreement is $150 and covers two visits, one for heating and one for cooling. That is separate from a diagnostic, which is a $75 visit aimed at a fault you already have.
If the visit turns up something that needs repairing, you get that price before anyone starts, and repairs carry a 30-day labor warranty. Nothing gets done on the day beyond the tune-up itself without you agreeing to it first.
Plenty of furnaces heat a house perfectly well while venting badly. We would rather find that in October than have you find it in January, and if the answer is that everything reads clean, that is the result and there is nothing to sell you.
| Running | Running safely | |
|---|---|---|
| What you'd notice | The house gets warm, so nothing seems wrong | Nothing either, which is the point |
| What decides it | The burner lights and the blower runs | What the flue reads, and whether the exchanger is sound |
| How you'd find out | When it finally stops, usually on a cold night | On a scheduled visit with a probe in the flue |
| What it costs | Nothing now, more later, and occasionally a great deal more | A booked visit at a time that suits you |
| Where it goes wrong | A furnace can run badly for years and never announce it | A clean set of readings is not a guarantee against a part failing next week |
We record the flue reading, temperature rise and safety checks whether we find a problem or not. If the furnace is operating normally, that gets documented too. Those numbers give you something real to compare against when the system is checked again next year.
If we find a cracked heat exchanger, the furnace is red-tagged and the gas is shut off before we leave. The heat exchanger separates combustion gases from the air moving through your home, so damage there is treated as a safety issue rather than another repair to put off.
Nero's Heating & Air works under Maryland HVAC/R license HVAC R 47671, with a Master HVAC license and EPA 608 certification. General liability and workers' compensation coverage are also in place, giving you clear, verifiable credentials behind the work being done in your home.
Before taking anything apart, we look at the equipment, the venting and the space around it. That gives us the starting condition before we begin testing combustion, airflow and the safety controls.
The burner is brought up and the flue read under real conditions, with the house pulling against it the way it does on a normal evening.
Each reading, what is normal for your furnace, and which figures have moved since last time. Anything needing work is priced separately before it starts.
The furnace completes a full cycle before we go, and the readings stay with the equipment documents so next year has something to compare against.
Heating work reaches across the whole region rather than clustering close to the shop, and a tune-up is the one visit that gets scheduled rather than squeezed into a day, so it travels further than an emergency call does. The towns below are where this work goes most often. If yours is not listed, it is still worth asking.
Not sure whether you need a tune-up or something more? Call us and tell us what the furnace has been doing. If it sounds like routine maintenance, we can get the tune-up scheduled. If the system is already struggling, we can point you toward a diagnostic instead.
If you know roughly how old the furnace is or when it was last serviced, mention that too. Changes like a finished basement, new weatherstripping or a crowded utility room can also affect how the furnace gets the air it needs.
Tell us when you call, even if it happened only once. That gives our technician an important starting point for the combustion and venting checks.
“Nero’s Heating & Air saved me in a pinch. I called and within an hour Julian was at my door and fixed my heat within 5 minutes. Unbelievable customer service. Very grateful for the quick response. Highly recommend to others.”
Caleb Hart
Because that is the first time all winter the system is asked for everything at once. Faults that were tolerable at half load stop being tolerable at full.
Yes, and more than an old one in one respect: most manufacturer parts warranties assume an annual professional service, and a claim can be refused where no record exists.
It is possible with fine abrasive cloth, though it means opening a gas appliance and reinstalling it correctly. Most homeowners are better off having it done during the annual visit.
After the visit, or during it. A fresh filter installed the day before hides how restricted the airflow had actually become, and that restriction is one of the readings worth having.
Not swept, but the venting does need checking. A liner that has deteriorated or a flue shared with a water heater is exactly what the draft test is looking for.
