Furnace Repair & Replacement

Reliable heat when you need it most.

Heat that fails in January is not a scheduling problem, it is an emergency. We repair, tune and replace gas and electric furnaces throughout Montgomery and Prince George's County, with combustion testing on every visit and 24-hour emergency service when the house is cold.

Why this matters

The work behind the work.

Natural gas from Washington Gas heats a large share of the homes in our service area, and the furnaces doing that work range from twelve year old 80 percent units to original equipment that has outlived two owners. A Maryland heating season is not brutal, but it is long, and it runs a furnace through thousands of ignition cycles between October and April.

Cracked heat exchangers, failed inducer motors, dirty flame sensors and lazy hot surface igniters are all products of that repetition. Home Comfort Air Services services and installs gas furnaces, electric furnaces and air handlers, boilers, and the venting and controls attached to them. Yosef founded the company in 2014 after working as a service technician, and safety practice is not negotiable here: any furnace we work on gets its combustion and venting checked, not just the part that failed.

That matters in the older housing stock inside the Beltway, where a furnace may share a masonry chimney with a water heater and where a decades old flue can be undersized for equipment installed later. We serve Silver Spring, Takoma Park, Adelphi, Hyattsville, Beltsville and the surrounding communities.

A Carrier gas furnace and evaporator coil in a basement, with PVC intake and exhaust, a new sheet metal supply trunk and a whole house humidifier on the return.

Fig. 01 · Furnace Repair & Replacement, on a recent job

How we work

How we run the job.

Repair, replacement or maintenance, the sequence is the same every time. You get the price before the work starts, and no surprises on the invoice.

Diagnose or assess

For a no-heat call we trace the sequence of operation to the exact point of failure. For a replacement we measure the home, run a load calculation, and evaluate the existing venting and ductwork.

Safety and combustion check

Gas equipment gets a combustion analysis, a flue and draft inspection, and a look at the heat exchanger, rollout switches and gas pressure before we sign off on anything as safe to run.

Options and price in writing

You see the finding, the fix and the cost before work begins. On replacements you get written options across efficiency levels, with venting and duct work spelled out rather than assumed.

Repair or install, then verify

We complete the work, retest combustion and temperature rise, confirm the blower speed matches the equipment, pull required permits, and leave documentation of readings and parts.

Methodology

How we actually do it.

A no-heat call gets traced through the sequence of operation rather than guessed at. Thermostat call, inducer start, pressure switch proving, igniter warmup, gas valve opening, flame sensing, blower delay: each step either happens or it does not, and where the sequence stops tells us where the fault is. We read the control board diagnostics, check gas pressure at the manifold, test the limit and rollout switches, and inspect the flame pattern.

Combustion analysis comes next on gas equipment. Measuring flue gas tells us whether the furnace is burning cleanly, whether it is venting the way it should, and whether carbon monoxide is present at levels that need attention. That test is also the honest way to evaluate a heat exchanger rather than relying on a hunch.

On the replacement side we start with a Manual J load calculation and a look at the ductwork, because an oversized furnace short cycles, wears itself out and leaves the far bedrooms cold. We also verify combustion air and venting, which is often the limiting factor in a tight townhouse closet or a finished basement.

Equipment

What you can install.

Gas furnaces come in two broad families. An 80 percent AFUE unit vents through a metal flue or chimney and is often the practical choice when the existing venting supports it. A 90 percent or higher condensing furnace pulls more heat out of the same gas, vents through PVC out a sidewall, and produces condensate that has to be drained and neutralized.

Going condensing usually means new venting and often means abandoning a shared chimney, which then has to be evaluated for the water heater that was sharing it. That is a real project detail, and we plan for it rather than discovering it on installation day. Single stage, two stage and modulating furnaces differ in how they deliver heat, and variable speed blowers make a noticeable difference in temperature swing and noise in a house where the return is undersized.

On the electric side, air handlers with heat strips are common in condos and townhomes, and pairing one with a heat pump is usually the cheaper way to heat. We also repair and replace boilers.

Project Day

The hours and the hand-off.

On a heating call the technician confirms the symptom, checks the thermostat and the filter, then goes to the furnace with a meter rather than a hunch. You will be told what failed and shown it where that is possible, including the flame sensor, the igniter or the control board diagnostic flash code. Prices are quoted before work starts.

If we find a cracked heat exchanger, an unsafe vent connection or carbon monoxide, we will tell you plainly and explain your options, including shutting the equipment down, and we do not use that finding as a sales tactic. Common ignition and control parts are usually stocked, so most repairs finish on the first visit.

Replacements are scheduled around your household, and we bring space heaters into the conversation if you have to wait overnight for a part in cold weather. Military members and seniors receive 10 percent off any repair, and 24-hour emergency service covers nights and weekends when the heat is out.

After the Install

The paperwork we handle for you.

Warranty coverage

Furnace parts carry a manufacturer warranty that varies by brand and model, and most brands require registration within a set window after installation to receive the full term. Heat exchangers typically carry longer coverage than other components, sometimes substantially longer, but the exact terms belong to the manufacturer and appear in your equipment documentation. We register new equipment for you and hand you the confirmation.

Our labor coverage is separate from the factory warranty and is stated in writing on your invoice or contract, backed by our 100 percent satisfaction guarantee. Keep your model and serial numbers, and keep records of annual maintenance, since some manufacturers require documented service to honor a claim. Work is performed under Maryland HVACR license MD70918. We are NATE certified, an ACCA member, Carrier authorized, and BBB accredited with an A+ rating.

Available incentives

Washington Gas offers residential rebates on qualifying high efficiency natural gas heating equipment for customers on its system, which covers most gas heated homes in our service area. Those programs generally set a minimum AFUE and require a licensed installation, and the paperwork goes faster when the invoice lists model numbers and efficiency ratings clearly.

On the electric side, Home Comfort Air Services participates in the Pepco and BGE residential rebate programs under Maryland EmPOWER, which is where heat pump and dual fuel projects find their incentives. The federal Section 25C credit that used to apply to this equipment ended for anything placed in service after December 31, 2025.

Program rules change from year to year, so we verify what is current at proposal time and give you the documentation needed to file rather than leaving you to chase it.

The Fine Print

Nothing buried in a 40-page document.

Repairs are not rebate eligible; utility and federal incentives apply to qualifying new equipment only. The $150 off installation and 10 percent military and senior repair offers cannot be combined with other promotions.

Service Area

Montgomery and Prince George's County.

We provide furnace repair & replacement in every city we cover. Click your city for what this job actually involves in those houses.

Silver Spring College Park Hyattsville Takoma Park Greenbelt White Oak Wheaton Bethesda Potomac Adelphi Beltsville New Carrollton Cheverly Bladensburg Brentwood

Questions

About this service

Questions we get about furnace repair & replacement.

My furnace blows cold air, what is going on?

Usually the burners are lighting and then dropping out. A dirty flame sensor is the most common cause: it stops proving flame, the gas valve closes, and the blower keeps running with no heat behind it. Other causes are a tripped limit switch from restricted airflow, a blocked flue, or a failed igniter. Change the filter first, then have the full ignition sequence tested.

What is combustion analysis and why does it matter?

It is a measurement of what the burner is actually producing, taken in the flue with an analyzer: oxygen, carbon monoxide, stack temperature and efficiency. It shows whether the furnace is burning cleanly, whether the heat exchanger is leaking combustion gases into the air you breathe, and whether the draft is correct. A visual inspection cannot tell you that, and carbon monoxide is not something to guess at.

How often should a gas furnace be serviced?

Once a year, in the fall, before you actually need the heat. The visit should include combustion analysis, a heat exchanger inspection, flue and draft check, ignition and flame sensor testing, safety control verification, and a look at the blower and filter. Most manufacturers, Carrier included, write documented annual maintenance into their warranty terms, so skipping it can cost you a parts claim later.

What does AFUE mean when comparing new furnaces?

AFUE is annual fuel utilization efficiency, the share of fuel energy that ends up as heat in the house instead of going up the flue. An 80 percent furnace sends about a fifth of it outside. A 90 plus condensing furnace recovers much more of that heat, which is why it needs PVC venting and a condensate drain. Those venting and drainage changes are part of the upgrade.

Is a cracked heat exchanger really a reason to replace?

Usually yes. A cracked heat exchanger can let combustion gases including carbon monoxide into the air you breathe, so the furnace has to be shut down until it is corrected. On a unit still inside its parts warranty the exchanger itself may be covered, though the labor rarely is and the job is heavy. On an older furnace that labor pushes the decision toward replacement.

What affects the cost of a furnace replacement?

Capacity and efficiency level first, then everything around the box. Moving from an 80 percent unit to a condensing furnace means new venting and a condensate drain. Older basements around here often need gas line, electrical or duct transition work. Access matters too, since a tight closet or a crawlspace takes longer. Permits apply in both counties. We also run $150 off a complete heating and cooling system.

Do I need a carbon monoxide detector with gas heat?

Yes, and Maryland requires detectors in homes with fuel burning appliances. Put one on every sleeping level, not just beside the furnace. Detectors expire, typically within seven to ten years, so check the date stamped on the housing. A working detector is a backup, not a substitute for annual combustion testing on the furnace, the water heater and every other Washington Gas appliance in the house.

Why does my furnace short cycle on the coldest mornings?

Short cycling means the burner runs briefly, shuts off and restarts. On a single digit January morning the usual culprit is restricted airflow tripping the high limit: a clogged filter, closed supply registers, or an undersized return that cannot feed the blower. Oversized equipment does it too, satisfying the thermostat before the house is comfortable. Both are worth diagnosing rather than living with all winter.

Before you call, or right after.

Ready to start?

Get a same-week estimate.

Schedule Service → 240.390.7442

Other services