Furnace Repair & Service in Silver Spring, MD

Furnace repair and service in Silver Spring, MD comes from JC & JC HVAC Mechanical Contractors, a licensed, family-owned team based on Maydale Drive in Silver Spring. We fix gas and electric furnaces that will not light, short cycle or blow cold air, with 24/7 emergency service. Schedule a furnace repair or call (301) 509-2475.

We are based in Silver Spring, where a furnace may sit in the basement of a brick colonial, Cape Cod or split-level. Basement furnaces face their own risks: moisture, renovation dust, cramped utility closets and older standard-efficiency units that have run for a long time. Below are the basement-furnace problems worth knowing. For general furnace troubleshooting, see our main furnace repair and service page.

Who can repair my furnace in Silver Spring?

JC & JC HVAC Mechanical Contractors is based in Silver Spring, MD, and 24/7 emergency service is available for no-heat calls.

When you call, we ask a few questions about the furnace: whether the furnace is gas or electric, whether it vents into a chimney or through PVC pipe, what the status light is doing, and when the problem started. That information can point toward an ignitor, a flame sensor, an inducer motor or something in the airflow side of the system.

When should a Silver Spring homeowner call for emergency furnace repair?

Call for emergency furnace service when you have no heat in freezing weather, when the furnace makes a loud bang at ignition, when you see scorching or soot, or when water is spreading from the unit.

Two situations call for someone other than an HVAC company first. If you smell natural gas, leave the house and call Washington Gas from outside. If a carbon monoxide alarm sounds, get everyone outdoors and call 911. Once the home is safe, our 24/7 line can get a technician out to find the cause and repair the furnace.

For a no-heat call in a cold snap, a few steps can help while you wait: make sure the furnace switch and breaker are on, replace a visibly clogged filter, and leave the furnace door closed, since a furnace with a door safety switch will not run with the panel off.

Why does a basement furnace in a Silver Spring home act up in the first cold week?

The first heavy heating days expose parts that sat idle all summer, so dust-coated flame sensors, cracked ignitors, seized inducer bearings and clogged filters tend to fail together when demand suddenly jumps.

Summer humidity in a basement can add to the problem. Damp air settles on the burner assembly, light rust forms on burners and the flame sensor, and a fine layer of corrosion builds on electrical terminals. When the thermostat finally calls for heat in late fall, the furnace tries to light and fails its flame proving or pressure switch checks. A pre-season tune-up can catch these before the cold arrives, and you can ask about our VIP Comfort Club maintenance plan.

Watch for these early-season warning signs in a basement furnace:

• A burning-dust smell that lingers longer than the first hour of operation
• The inducer motor humming loudly or rattling before ignition
• Several ignition attempts before the burners stay lit
• A blinking status light after the furnace gives up

Is my finished-basement furnace getting enough combustion air?

A furnace closed into a small room during a basement finish may not get the combustion air it needs, which can cause poor burning, soot, flame rollout or draft problems in a chimney-vented unit.

When a basement is finished, the furnace can end up in a utility closet with a solid door. A standard-efficiency furnace draws its combustion air from the room it sits in. If that room is too tight, the burners starve for oxygen and the chimney draft weakens, especially when bath fans and a dryer are running. We check the closet volume, door louvers and any dedicated air openings, and we can perform combustion testing to confirm the burners are getting what they need.

Finishing work causes a second problem: drywall and sanding dust pulled into the return. That fine dust clogs filters quickly and coats the blower wheel, which reduces airflow and makes the high-limit switch trip. If your furnace started overheating after a renovation, the blower and filter are the first places we look.

If your furnace closet doubles as storage, keep paint, cleaners and laundry products well away from the furnace. Chemical vapors drawn into the burners corrode heat exchangers and flame sensors over time, and stored boxes can block the airflow the furnace needs.

Why does my older chimney-vented furnace keep shutting down?

A standard-efficiency furnace that vents into a masonry chimney can shut down on a blocked or weak draft, a rusted flue connector, or a tripped spill or rollout switch, all of which point to exhaust not leaving the house properly.

In an older home, the furnace may still vent into the original brick chimney through a metal connector pipe. Over time that connector rusts, loose joints separate, and debris, mortar or animal nests collect at the base of the chimney. Unlined masonry chimneys can also deteriorate from years of acidic flue gases. When draft weakens, exhaust can spill back at the draft hood and trip a safety switch. That is a warning, not a nuisance, and the switch should never be bypassed or simply reset over and over. We inspect the connector, check draft with the furnace running, and test for carbon monoxide at the furnace and in the living area before recommending a repair or a chimney liner.

Why does my high-efficiency furnace shut down when the condensate pump fails?

A condensing furnace makes water as part of normal operation, and if the condensate pump or drain backs up, a safety switch stops the furnace to keep the water from flooding the cabinet or the basement floor.

In basements without a floor drain near the furnace, condensate is pumped to a laundry sink, sump or outdoor line. Those small pumps fail, their check valves stick, and their lines clog with algae and debris. Inside the furnace, the trap and the inducer drain can also plug, and water backing up into the inducer housing keeps the pressure switch from closing. The result is a furnace that tries to start, then shuts down with a pressure switch code. A pump with a safety float switch can also cut power to the furnace when the pump fails, so a failed pump can leave the house without heat even though the burners and controls are fine. We clear the trap, flush the lines, test or replace the pump and confirm the pressure switch closes reliably.

What to expect during your visit

Your technician will ask what you have noticed, test the furnace step by step through a heating cycle, explain the failed part and the repair, and complete the work after you approve.

• We read the control board code and check the filter, blower and burner area
• We watch the ignition sequence and measure flame sensor signal and gas pressure
• We inspect the vent connection, the chimney connector or PVC piping, and the condensate system
• We check combustion air and look for signs of rollout or soot
• We repair or replace the failed part and run a complete heating cycle to confirm the fix

Our repairs are backed by the 1-Year Workmanship Warranty.

Related services in Silver Spring

If your furnace is part of a larger heating question, see heating repair in Silver Spring. Homes with radiators rather than ducts are served by our boiler repair in Silver Spring. When a repair no longer makes sense, our Silver Spring furnace replacement page explains the next step. More local information is on our Silver Spring service area page.

Get your Silver Spring furnace back on

We are based in Silver Spring and offer 24/7 emergency service. Call (301) 509-2475 or request furnace repair online. If the news is a replacement, financing can help spread out the cost.