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

Maryland · Heating · 24/7 emergency

Boiler Repair Service in Maryland

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.

Hydronic work is a specialty, and it is disappearing. Plenty of HVAC companies in this market will happily replace your air conditioner and quietly hope you never ask about the boiler in the basement. We repair steam and hot-water systems every winter, including one-pipe steam systems with original main vents and cast-iron sectional boilers older than the technicians working on them.

The most common calls are no heat in one zone, banging pipes, a boiler that will not maintain pressure, a low-water cutoff locking the unit out, and a system that heats the first floor but not the third. Every one of those has a diagnosable cause — air in the loop, a failed circulator or zone valve, a waterlogged expansion tank, a clogged main vent, or wet steam from a boiler that needs skimming. Guessing is expensive; measuring is not.

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

  • Full hydronic diagnosis: pressure, temperature, circulator operation, zone valve function and air content
  • Steam-specific service: main vents, radiator vents, pigtails, low-water cutoff and skimming
  • Expansion tank test and recharge or replacement
  • Circulator and zone valve replacement, with correct flow direction and isolation flanges
  • Combustion analysis and CO test on gas- and oil-fired boilers
  • System purge of trapped air, zone by zone
  • Water treatment check on closed-loop systems

Maryland specifics

Code, permits and rebates

Boiler repairs do not require a Montgomery County permit, but replacement does, and any gas piping alteration does. Maryland's carbon monoxide alarm requirements apply to homes with fuel-burning boilers, and older atmospheric boilers sharing a masonry chimney are a common source of draft problems in this area — particularly after a high-efficiency furnace or water heater has been installed alongside and orphaned the flue. We check draft on every boiler visit.

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 repair job

  1. Identify the system type first

    One-pipe steam, two-pipe steam, gravity-converted hot water and modern zoned hot water all fail differently and get diagnosed differently. Half of bad boiler repairs start with a technician treating a steam system like a hot-water system.

  2. Read the gauges

    Pressure, temperature and the sight glass tell the story. Steam systems should run at ounces of pressure, not pounds — a pressuretrol set at 5 psi on a residential one-pipe system is a classic cause of banging, uneven heat and wasted fuel.

  3. Trace the affected zone

    For a cold zone we check the circulator or zone valve, the thermostat call, and whether the loop is airbound. For a cold radiator on steam, we check the vent, the pitch and the supply valve before assuming a boiler problem.

  4. Repair and rebalance

    After the repair we purge air, verify every zone comes up to temperature, and re-check pressure at operating temperature — not cold.

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.

Component versus system fault

A radiator vent or thermocouple is a small repair. A failed circulator, zone valve or aquastat is moderate. A cracked section in a cast-iron boiler or a leaking heat exchanger in a condensing unit is a replacement conversation.

Access and age

Sixty-year-old threaded black iron in a tight Takoma Park basement does not disassemble as cooperatively as modern piping. We quote realistically rather than optimistically.

Parts for legacy equipment

Many parts for older Weil-McLain, Burnham and Peerless boilers are still available. Some obsolete controls are not, and the honest answer is sometimes a control retrofit instead of a like-for-like replacement.

Questions

Boiler Repair Service questions

Why do my pipes bang when the heat comes on?
On steam systems, banging is almost always water trapped where steam wants to travel — from poor pitch on a radiator or main, a failed steam trap on two-pipe systems, or excessive boiler pressure. On hot-water systems it is usually thermal expansion against a pipe hanger or air in the loop. It is fixable and it is not something you should live with.
One radiator stays cold while the rest heat. What is wrong?
On steam, the vent on that radiator is likely clogged, or the radiator has settled and no longer pitches back toward the supply. On hot water, that zone is probably airbound or its zone valve has failed. Both are typically same-visit repairs.
My boiler keeps losing pressure. Is that serious?
It means water is leaving the system somewhere — a weeping relief valve, a failed expansion tank, a leaking circulator flange, or a slow leak in buried or concealed piping. Continuously adding fresh water to a closed loop introduces oxygen and minerals, which corrodes the boiler from the inside. It is worth finding the source rather than topping it up each month.
Do you service oil-fired boilers?
Yes. Oil-fired boilers are still in service in parts of Olney, outer Silver Spring and older properties without gas service. Nozzle, electrode, pump pressure and combustion setup all matter more on oil than on gas, and a proper combustion analysis makes a measurable difference to fuel use.

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