Licensed Maryland HVACR contractor · 41 years in Montgomery County 24/7 emergency service
Poteete HVAC · since 1985

Montgomery County, Maryland · Established 1985

Four decades of getting Maryland houses comfortable.

Poteete HVAC installs and repairs heating and cooling systems across Silver Spring, Takoma Park, Bethesda, Potomac, Olney and Germantown. We measure the house before we quote the equipment, we pull the permit, and we leave the readings on the invoice.

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  • Manual J load calculation before any equipment is specified
  • 500 microns verified vacuum on every refrigerant circuit
  • Permit filed with Montgomery County DPS and inspection attended
The Maryland comfort year A radial chart of monthly heating and cooling degree-days for the Washington–Maryland area. Heating demand peaks from December through February and cooling demand peaks in July and August, with short shoulder seasons in between. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 4,000 HDD 1,200 CDD
Montgomery County runs roughly 4,000 heating degree-days against 1,200 cooling degree-days a year. Ember bars read outward for heating demand, ice bars inward for cooling. Equipment here has to be genuinely good at both — which is why we size on measured load rather than on a rule of thumb.
41+ years Installing in Montgomery County since 1985
Licensed MD HVACR State-licensed, bonded and insured
Permits filed We pull the county mechanical permit
24/7 emergency No heat and no cool calls answered

Services

Fifteen services, split the way the equipment actually splits.

Heating on the ember side, cooling on the ice side, water heating and whole-system work between them. Every service page covers the process, what moves the price, and the Maryland code and rebate detail that applies to it.

Heating

Furnaces, boilers and heat pumps

Heating

Heating & Furnace Installation

High-efficiency gas furnaces and heat pumps sized by load calculation, with combustion analysis and venting done to code — not eyeballed.

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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.

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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.

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Heating · 24/7

Boiler Repair Service

Steam and hot-water boiler repair by technicians who actually work on hydronic systems — including the 60-year-old ones still heating half of Takoma Park.

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Cooling

Air conditioning, central air and ductless systems

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.

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Cooling · 24/7

Air Conditioning Repair Services

Same-day diagnosis on no-cool calls, with the actual measurement that identified the fault written on your invoice — not just a part name.

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Cooling

Central Air Conditioning System Installation

Whole-house central air for homes that have never had it, including the duct design work that decides whether the second floor is actually comfortable.

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Cooling

Ductless Air Conditioning System Installation

Mini-split systems for additions, converted attics, sunrooms and older homes where running ductwork would cost more than the equipment.

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Water heating

Tank, hybrid and tankless water heaters

Water heating

Hot Water Heater Installation

Gas, electric and heat-pump water heaters installed to code with expansion control, proper venting and a permit — usually same day.

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Water heating · 24/7

Hot Water Heater Repair

No hot water, leaking tank, pilot that will not stay lit — diagnosed same day, with an honest call on repair versus replacement.

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Water heating

Tankless Water Heater Installation

Condensing tankless systems installed with the gas line, venting and isolation valves the manufacturer actually requires — including the parts most installers skip.

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Water heating · 24/7

Tankless Water Heater Repair

Error codes, scaling, ignition faults and flow problems on all major tankless brands — with descaling that restores the output you paid for.

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Whole system

Full installation, repair and ductwork

Whole system

HVAC Installers

Complete heating and cooling system installation by a crew that has been replacing systems in Montgomery County since 1985.

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Whole system · 24/7

HVAC Repair

One number for heating, cooling, heat pump and control faults — diagnosed by measurement, with the readings written on your invoice.

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Whole system

Duct Cleaning Services

NADCA-method source removal with before-and-after camera documentation — and an honest answer about whether your ducts actually need it.

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How it works

An air conditioner does not make cold. It moves heat.

Everything we diagnose follows from that. Refrigerant absorbs heat indoors at the evaporator coil, the compressor raises its pressure and temperature, and the condenser rejects that heat to the outdoor air. When a system underperforms, the fault is in one of those four stages or in the air moving across the coils — and each one is measurable.

That is why a technician who quotes you a part without giving you a superheat and subcooling reading has guessed. We write the numbers on the invoice so the next person who opens your system, including us in three winters, starts from data rather than from scratch.

How we diagnose
How a split system works An indoor air handler and evaporator coil connected by an insulated line set to an outdoor condensing unit, with supply and return ductwork inside the house. Conditioned space Supply Return Air handler + coil Condensing unit Suction Liquid
Heat is absorbed indoors at the evaporator coil, carried outdoors through the insulated suction line, and rejected at the condenser. The two halves are a matched pair — replacing one and keeping the other is what invalidates the efficiency rating on the label.

The number nobody measures

Most comfort complaints in this county are airflow complaints.

A great deal of Maryland housing runs modern equipment on distribution that was designed for something else — gravity-era trunks in Silver Spring, single undersized builder returns in Germantown, thirty-year-old flex duct baking in a 130-degree Olney attic. The equipment tests fine. The house is still uncomfortable.

Total external static pressure settles it in about ten minutes. Above roughly 0.8 in. w.c., a new system will run hard, remove less humidity and fail early no matter whose name is on the cabinet. We take that reading before we quote, and where the ductwork is the problem we say so — even when the ductwork is the cheaper sale.

Ductwork and air quality
Trunk and branch duct system A supply plenum feeding a tapered trunk with branch runs to registers, alongside an undersized single return, with static pressure measurement points marked. Air handler Supply pressure Return pressure Tapered trunk Branch runs to registers Return
Total external static pressure is the sum of both readings, and it is the single most revealing number in a duct system. Above roughly 0.8 in. w.c., new equipment will run hard and die young — which is why we measure before quoting rather than after installing.
Poteete HVAC service area A schematic map of the Montgomery County, Maryland service area showing Germantown, Olney, Potomac, Bethesda, Silver Spring and Takoma Park, with the I-270 and I-495 corridors. I-270 I-495 Silver Spring Olney Potomac Bethesda Germantown Takoma Park Montgomery County, Maryland — schematic, not to scale
Six core service areas across Montgomery County, all inside a thirty-mile radius of our Olney base. Each one has its own housing stock, its own permitting quirks and, in places like Glen Hills and outer Olney, its own utility situation — which is why we write about them separately rather than treating the county as one market.

Areas served

Six markets, six completely different sets of problems.

A 1912 Takoma Park bungalow in a historic district, a Bethesda Tudor renovated three times, a Potomac property on propane and a private well, a Germantown townhouse with a mechanical closet built to 1994 dimensions. These are not variations on one job. Pick your town and we will tell you what we actually find in those houses.

Silver Spring, MD 20901 · 20902 · 20903 Olney, MD 20832 · 20830 · 20833 Potomac, MD 20854 · 20859 Bethesda, MD 20814 · 20816 · 20817 Germantown, MD 20874 · 20876 · 20875 Takoma Park, MD 20912
All service areas

41 years

The trade changed five times. We were here for all of it.

Longevity in this business is not sentiment, it is accumulated pattern recognition. Every one of these transitions left a specific kind of problem inside Maryland houses, and we still open basements and find each of them.

  1. 1985

    The company starts

    Founded to install and service heating and cooling in Montgomery County, working the same neighbourhoods we work today. A great many of the systems we replace now are the second or third generation on a house we first visited decades ago.

  2. 1995

    The oil-to-gas decade

    Washington Gas mains reached deeper into Silver Spring, Colesville and the Olney corridor, and we converted hundreds of oil-fired systems — learning, permanently, how much of a conversion is chimney and venting work rather than equipment work.

  3. 2010

    R-22 phase-down

    The move to R-410A rewrote service practice: new line-set standards, new charging procedure, and a long tail of R-22 systems that are still out there and still uneconomical to recharge. We have been having that honest conversation with homeowners for fifteen years.

  4. 2023

    SEER2 and 95% AFUE

    New federal minimums put most Maryland furnace replacements into the condensing class and raised air conditioning efficiency floors. That changed installations more than appliances — PVC venting, condensate drains and orphaned water heaters became routine scope.

  5. 2025

    The A2L transition

    Systems now ship with A2L refrigerants such as R-454B, requiring different handling, different tooling and different service procedure. We are certified and equipped for A2L, R-410A and the legacy R-22 equipment still running across older Montgomery County housing.

Questions

What Maryland homeowners ask us first

What areas of Maryland does Poteete HVAC serve?
We work across Montgomery County from our base in Olney, with core coverage in Silver Spring, Takoma Park, Bethesda, Potomac, Olney and Germantown, and roughly a 30-mile radius around that. Each of those markets has different housing stock and different permitting realities, which is why we write about them separately rather than treating the county as one place.
How do I know whether to repair or replace my system?
The practical test is age over fifteen years, a repair costing more than about a third of replacement, R-22 refrigerant, or a second significant failure inside two years. Any two of those together generally point toward replacement. We give you both numbers at the same visit and let you decide rather than steering you.
Do you pull the permit for equipment replacement?
Yes. Montgomery County requires a mechanical permit for equipment replacement, and we file it, schedule the inspection and meet the inspector. Unpermitted mechanical work can void a manufacturer warranty and reliably surfaces on the home inspection report when you sell.
Why does system sizing matter so much?
Because an oversized system satisfies the thermostat before it has removed any humidity, which is exactly why so many Maryland homes are cold and clammy in July. We run a room-by-room Manual J load calculation and read static pressure on the existing ductwork before we quote equipment. It takes an hour and it is the difference between a system that works and one you will complain about for fifteen years.
Do you offer emergency service?
Yes, around the clock for no-heat and no-cool calls. We hold same-day emergency capacity through both seasons and prioritise households with infants, elderly residents or medical needs. During a regional heat advisory the whole market is saturated, so we give you an honest arrival window rather than an optimistic one.

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.

Call (301) 555-0182 Request a quote

Mon–Fri 7:00am–6:00pm · Saturday 8:00am–2:00pm · 24/7 emergency service