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

Maryland · Water heating

Tankless Water Heater Installation in Maryland

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

A tankless water heater is not a drop-in replacement for a tank, and every homeowner disappointed by one was sold it as though it were. A condensing tankless unit typically needs a gas supply of 150,000 to 199,000 BTU — often two or three times what the old tank drew — which frequently means upsizing the gas line back toward the meter. It needs stainless or polypropylene venting, a condensate drain, and isolation valves for descaling. Skip any of those and you get a unit that throttles, error-codes, or scales shut in four years.

Done properly, it is excellent: unlimited hot water, a wall-mounted footprint that frees up floor space in a tight basement or closet, and 20-plus year service life against 10 for a tank. We size on flow rate at your groundwater temperature, verify the gas supply, and install the service valves so the annual descale takes twenty minutes instead of a plumbing project.

Where we work
Tankless water heater flow Cold water entering a flow sensor, passing through a modulating burner and heat exchanger, exiting hot on demand, with isolation service valves and a condensate drain. Cold supply Flow sensor Hot, on demand Gas — up to 199,000 BTU Modulating heat exchanger Service valves Condensate
Nothing heats until a tap opens. The two things that decide whether a tankless unit performs are the gas supply — often two or three times what the old tank drew — and the descaling interval. Isolation valves are standard on our installations because without them, that annual service becomes a plumbing project.

Scope

What the job actually includes

  • Flow-rate sizing based on simultaneous fixture demand and Maryland winter groundwater temperature
  • Gas line load calculation from the meter, with upsizing quoted up front if required
  • Stainless steel or polypropylene venting, correctly sloped, with approved termination clearances
  • Condensate drain with neutralizer on condensing units
  • Isolation and service valve kit installed as standard — required for descaling and for the warranty
  • Water quality assessment and scale protection strategy, essential on well water
  • Recirculation options where a long run to a distant bathroom makes wait time the real complaint
  • Permit filed, inspection attended, warranty registered

Maryland specifics

Code, permits and rebates

Montgomery County requires a permit for tankless installation, and gas piping alterations are inspected. Condensing tankless units can qualify for EmPOWER Maryland gas rebates through Washington Gas and for the federal 25C credit at qualifying efficiency levels. Maryland's 2021 IECC adoption also drives the efficiency floor. One local caution: homes served by private wells in Olney, Glen Hills and outer Potomac frequently have hardness and iron levels that will scale a tankless heat exchanger quickly — annual descaling and, in many cases, pre-treatment are not optional there.

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 tankless installation job

  1. Flow rate and temperature rise

    Maryland groundwater runs near 50°F in winter. To deliver 120°F you need a 70-degree rise, which cuts a unit's advertised gallons-per-minute figure substantially. We size on winter performance, because that is when you will notice if we did not.

  2. Gas supply verification

    We calculate the total connected gas load and the pipe length back to the meter. If the existing half-inch or three-quarter-inch line cannot support the unit, we tell you the upsizing cost before you commit — not after the unit is on the wall.

  3. Vent routing and condensate

    Termination clearances to windows, doors, soffits and property lines govern where the vent can exit. On tight lots in Bethesda, Takoma Park and Germantown townhomes, this is often the constraint that determines where the unit is mounted.

  4. Install and commission

    Unit mounted, gas and water connected, isolation valves fitted, vent sealed and pressure-tested, temperature set, and flow verified at multiple fixtures simultaneously so you see real performance before we leave.

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.

Gas line upsizing

This is the single largest variable. A short run from a nearby meter is minor. Running a new three-quarter or one-inch line across a finished basement to reach the meter is a real line item.

Venting complexity

A short sidewall termination is straightforward. A run through a finished ceiling to reach an approved exterior location is not.

Water treatment

On well water or hard water, a scale filter or softener protects the heat exchanger. It costs money up front and prevents the most expensive tankless failure mode there is.

Recirculation

If your complaint is wait time rather than capacity, a recirculation loop or a unit with a built-in buffer tank solves it. Adding a dedicated return line in a finished house adds cost.

Questions

Tankless Water Heater Installation questions

Will a tankless unit really give me unlimited hot water?
Unlimited in duration, limited in flow rate. A correctly sized unit will run two showers indefinitely; running two showers, a dishwasher and a laundry fill simultaneously in January will exceed most residential units. Sizing on winter temperature rise is what determines whether you notice that limit.
Does a tankless water heater need maintenance?
Yes — annual descaling, and more often on hard or well water. This is the most-skipped maintenance item in the category and the leading cause of premature heat exchanger failure. We install isolation valves on every unit specifically so the descale is quick and inexpensive.
Is tankless worth it compared to a good tank?
It depends on what you value. Efficiency gains are real but modest against a modern tank; the genuine wins are endless duration, the floor space you get back, and roughly double the service life. If your gas line needs major upsizing and you have plenty of space, a high-efficiency tank is often the better financial answer, and we will say so.
Why does my existing tankless run hot then cold?
The classic cold-water sandwich comes from the burner cycling between draws, and it is worse on undersized or non-modulating units. It can also indicate scaling, an undersized gas supply causing the burner to drop out, or a crossover between hot and cold at a mixing valve elsewhere in the house.

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

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