Maryland · Heating
Heating & Furnace Installation in Maryland
High-efficiency gas furnaces and heat pumps sized by load calculation, with combustion analysis and venting done to code — not eyeballed.
A furnace replacement is a combustion appliance installation, and it deserves to be treated as one. The three things that go wrong most often in this market are oversizing, improper venting on 90%-plus condensing equipment, and reusing a duct system that cannot handle the new blower. All three are avoidable, and all three are measurable before the old furnace comes out.
We calculate the heating load, read static pressure on the existing ducts, verify that the flue or the new PVC vent route can be run to code, and confirm the combustion air supply and condensate route. Then we install, and we finish with a combustion analysis printout showing carbon monoxide in the flue, draft and temperature rise inside the manufacturer's specified range. That printout is the difference between a furnace that was installed and a furnace that was merely connected.
Where we workScope
What the job actually includes
- Manual J heating load calculation for the actual house, including the additions
- Total external static pressure reading before equipment selection
- New furnace set level with proper clearances, new plenum transitions and sealed connections
- Code-compliant venting: PVC intake and exhaust for condensing units, or verified draft for 80% units
- Condensate neutralizer and properly trapped drain on condensing furnaces
- New flexible gas connector, sediment trap, and a leak check on every joint
- Combustion analysis with CO, draft and temperature rise recorded on a commissioning sheet
- County mechanical permit filed and final inspection attended
Maryland specifics
Code, permits and rebates
Federal minimum efficiency for new residential gas furnaces has risen to 95% AFUE for most models, which means most Maryland replacements are now condensing furnaces that require PVC venting and a condensate drain — a bigger change to an older house than homeowners expect. Maryland follows the 2021 IECC and the state-adopted mechanical and fuel gas codes; Montgomery County DPS issues the mechanical permit and inspects the work. EmPOWER Maryland rebates through Washington Gas and Pepco, plus the federal 25C credit, can apply to qualifying high-efficiency furnaces and heat pumps.
Licensing
MD HVACR Contractor License #01-XXXXX. All refrigerant handling is performed by EPA Section 608 certified technicians, and equipment replacement is permitted and inspected through the county.
Process
How we run a furnace installation job
-
Load calculation and venting survey
The heating load of a 1948 Silver Spring cape that has since been insulated and re-windowed is frequently 30 to 40 percent below its original furnace size. We also determine early whether a condensing furnace can be vented — sidewall termination clearances to windows, doors, meters and property lines are the constraint on tight lots.
-
Orphaned water heater check
When an 80% furnace that shared a masonry chimney is replaced with a 90%-plus condensing unit, the water heater is left alone in an oversized flue and can fail to draft, spilling combustion products. We check this on every quote. It is the most commonly missed item in furnace replacement across older Maryland housing stock.
-
Equipment selection
Single-stage, two-stage, or modulating with a variable-speed ECM blower. Modulating equipment runs long, low and quiet, which in a drafty older home is a comfort improvement you feel every evening, not just a number on an efficiency label.
-
Installation and gas work
Old unit recovered and removed, new furnace set and sealed to the plenum, gas line sized and leak-tested, venting run with correct slope back to the unit, and the condensate drain trapped and neutralized.
-
Commissioning
Gas pressure verified at the manifold, temperature rise measured against the data plate range, CO in the flue recorded, and safeties tested. You get the printout.
Pricing
What moves the price
We do not publish a single number, because a number without your house attached to it is marketing rather than information. These are the variables that actually decide what a job costs, and we itemise all of them in writing before any work begins.
Efficiency and staging
An 80% single-stage furnace is the budget floor. A 96% modulating furnace with an ECM blower costs meaningfully more and reduces both gas use and the temperature swing you feel between cycles.
Venting changes
Moving from a chimney-vented 80% unit to a sidewall-vented condensing furnace means new PVC intake and exhaust, core drilling through the foundation or rim joist, and often a chimney liner for the orphaned water heater. That work is real and we itemize it.
Duct and electrical corrections
Undersized returns and unsealed plenums shorten equipment life. Where static pressure reads high, we quote the return-side correction separately so you can see exactly what it buys.
Fuel conversion
Oil-to-gas and propane-to-gas conversions add gas line work, meter coordination with Washington Gas, tank removal and sometimes a chimney liner. These are common in Olney's outlying roads and in older Silver Spring pockets.
Local coverage
Heating & Furnace Installation by service area
Every one of these pages is written for that specific market — the housing stock we actually find there, the permitting authority, the utility situation and the failure patterns that repeat in those streets.
Montgomery County
Furnace Installation in Silver Spring
Furnace replacement on Silver Spring's converted, patched and re-patched duct systems
Read more →Montgomery County
Furnace Installation in Olney
Heat pump and furnace replacement across Olney
Read more →Montgomery County
Furnace Installation in Potomac
Heating replacement in Potomac, including propane and no-gas-main properties
Read more →Montgomery County
Furnace Installation in Bethesda
Furnace and heat pump replacement in Bethesda's renovated housing stock
Read more →Montgomery County
Furnace Installation in Germantown
Furnace replacement in Germantown's tight mechanical closets
Read more →Montgomery County
Furnace Installation in Takoma Park
Furnace and heat pump installation in a city with almost no ductwork
Read more →Questions
Heating & Furnace Installation questions
How long should a furnace last in Maryland?
Should I replace my furnace with a heat pump instead?
Why does my furnace turn on and off every few minutes?
Do you handle the permit?
Related
Work that usually comes up alongside this
Heating · 24/7
Heating & Furnace Repair Service
No-heat calls answered around the clock in winter, with combustion safety testing on every visit — including a carbon monoxide check.
Read more →Whole system
HVAC Installers
Complete heating and cooling system installation by a crew that has been replacing systems in Montgomery County since 1985.
Read more →Heating
Boiler Installation
Modern condensing and cast-iron boilers installed on existing radiator systems, with a real heat-loss calculation instead of matching the old nameplate.
Read more →Cooling
Air Conditioning Installation
Right-sized air conditioning installed to Manual J load calculations, with the county mechanical permit pulled and the ductwork checked before we quote.
Read more →Talk to a technician
Tell us what the house is doing.
Describe the problem and we will tell you what it usually means, what it typically costs to diagnose, and when we can be there. No obligation, no scripted sales call.
Mon–Fri 7:00am–6:00pm · Saturday 8:00am–2:00pm · 24/7 emergency service