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

Maryland · Heating

Boiler Installation in Maryland

Modern condensing and cast-iron boilers installed on existing radiator systems, with a real heat-loss calculation instead of matching the old nameplate.

Hydronic heat is everywhere in this part of Maryland. Steam and hot-water boilers feeding cast-iron radiators heat a large share of pre-1955 housing in Takoma Park, Silver Spring and the older sections of Bethesda, and they are genuinely excellent heating systems — quiet, even, and comfortable in a way that forced air is not. The mistake is replacing a failing boiler by matching the BTU rating on the old one, which was itself sized for an uninsulated house with single-pane windows.

We perform a room-by-room heat loss calculation and, critically, we measure the connected radiator capacity. Sizing a modulating condensing boiler to a load it can actually modulate down to is what determines whether you get the efficiency you paid for. A 199,000 BTU condensing boiler on a house with a 55,000 BTU load will short-cycle and never reach condensing temperatures — which means it will burn gas like the old one while costing five times as much.

Where we work
Hydronic heating loop A boiler feeding hot water through a supply main to cast-iron radiators, returning cooler water through a circulator and expansion tank. Boiler Circulator Radiator Radiator Expansion Reset Supply — heated water out Return — cooled water back
Cast-iron radiators are worth keeping. What is worth replacing is a boiler sized to a house that no longer exists — one that has since been insulated and re-windowed. Outdoor reset is where the comfort gain lives: 130-degree water circulating steadily beats 180-degree water in short bursts.

Scope

What the job actually includes

  • Room-by-room heat loss calculation plus connected radiator EDR measurement
  • Boiler selection matched to load and turndown ratio — sized to modulate, not just to fire
  • Near-boiler piping built to the manufacturer's specification, including primary/secondary where required
  • New circulator sized to the system head, with proper flow direction and air separation
  • Expansion tank, backflow preventer, pressure-reducing valve and low-water cutoff as required
  • Outdoor reset control configured — the single biggest efficiency gain on a hydronic system
  • Condensate neutralizer, venting to code, and full combustion analysis at commissioning
  • System flush, chemical treatment and complete air purge on every zone

Maryland specifics

Code, permits and rebates

Montgomery County DPS requires a mechanical permit for boiler replacement and inspects the installation, including venting and gas piping. Maryland follows the state-adopted fuel gas and mechanical codes with the 2021 IECC, which requires controls such as outdoor reset on many new hydronic systems. High-efficiency condensing boilers can qualify for EmPOWER Maryland rebates through Washington Gas as well as the federal 25C credit. In Takoma Park and other historic districts, sidewall vent terminations on a street-facing elevation may need preservation review, which we factor into vent routing at design time.

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 boiler installation job

  1. Heat loss and radiator survey

    We measure every radiator to establish real connected capacity, then calculate the actual heat loss. In a 1928 Takoma Park home that has since been insulated, those two numbers can differ by a factor of two — and only one of them should size the boiler.

  2. Steam versus hot water decision

    One-pipe steam systems are not simply upgradable to condensing hot water without replacing the distribution. We will tell you honestly which category your system is in, because a contractor who quotes a condensing boiler on a one-pipe steam system has not looked at your basement.

  3. Piping design

    Near-boiler piping is where most condensing boiler installations fail. We build to the manufacturer's diagram, with proper primary/secondary separation, correct circulator placement relative to the expansion tank, and a real air elimination strategy.

  4. Installation and venting

    Old boiler drained, cut out and removed, new unit set, piped, gas-connected and vented. Condensing boilers vent in PVC or polypropylene through a sidewall, which frequently frees up the chimney and requires a liner for the water heater left behind.

  5. Purge, balance and commission

    Every zone purged of air, outdoor reset curve set for the house, combustion analyzed and recorded. We come back after the first cold snap to fine-tune the reset curve against how the house actually behaves.

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.

Condensing versus conventional

A modulating condensing boiler at 95% AFUE costs substantially more than a cast-iron atmospheric boiler at 84%, and needs the right emitters and water temperatures to reach its rated efficiency. On a high-temperature cast-iron radiator system without oversized emitters, the real-world gap narrows and sometimes the conventional boiler is the honest recommendation.

Near-boiler piping scope

Sixty-year-old black iron near-boiler piping usually cannot be reused. Rebuilding it properly is labor, and it is the labor that determines whether the new boiler lasts.

Venting and chimney work

Sidewall venting a condensing boiler often orphans the water heater in the chimney, requiring a stainless liner. Budget for it rather than discovering it.

Zoning

Adding zone valves or circulators to separate floors is frequently the best comfort money in the project, especially in three-story homes where the top floor overheats.

Questions

Boiler Installation questions

Can I keep my cast-iron radiators with a new boiler?
Almost always, and you should — cast-iron radiators are durable, they hold heat beautifully, and replacing them buys you nothing. What changes is the boiler, the controls and often the circulator and piping. Many homeowners are surprised that the most comfortable part of their house is the part we are not touching.
What is outdoor reset and why does it matter?
Outdoor reset varies the boiler water temperature based on the outdoor temperature, so on a 45-degree day the system circulates 120-degree water instead of 180-degree water. It produces steadier room temperatures and, on a condensing boiler, is what actually allows the unit to condense and reach its rated efficiency. It is included on our installations by default.
How long does a boiler installation take?
A straightforward hot-water boiler replacement is typically two to three days including piping, venting and purging. Steam boiler replacements and jobs that involve a chimney liner or significant repiping run longer. We schedule heating-season replacements so you are without heat for as little as possible, usually a single day.
My boiler is 45 years old but still works. Should I replace it?
Not necessarily on age alone — old cast-iron boilers are famously durable. The questions are its efficiency, whether the heat exchanger is sound, whether parts are still available, and what a failure in January would cost you. Planned replacement in September is a considerably better experience and price than emergency replacement in a cold snap.

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