Dupont Circle was largely built out between the 1880s and the early 1900s, which means the heat under most of these rowhouses and grand old mansions started life as steam or hot-water heat fed by a single cast-iron boiler in the basement. Decades later, that's still what's keeping you warm: ornate column radiators under the bay windows, a riser snaking up through the closets, and a boiler that has outlived several owners. We specialize in exactly this kind of system — the one-pipe steam and gravity-converted hydronic setups that forced-air technicians tend to avoid because the rules are different. Bleeding, balancing, steam-trap work, and reading the pitch on an eighty-year-old runout are the daily work here, not an unfamiliar side job.
The way these houses were built shapes every repair. Dupont's narrow, three- and four-story floor plans put the boiler far below the top-floor bedrooms, so the upper radiators starve for steam while the parlor floor overheats — a balancing problem, not a broken boiler. Original mains buried behind plaster and sagging over a century cause the water hammer that rattles your evenings. Mansion-scale homes carved into apartments or offices often run radiators on mismatched valves and orphaned traps nobody has touched in years. We trace the system back to how it was designed to work, then fix the actual fault: a clogged main vent, a failed trap, a low water line, a leak at a spud or union — rather than throwing parts at the symptom.
Dupont Circle note: Much of Dupont Circle sits inside a designated historic district, and a lot of those embassy-row mansions and rowhouses are now condos and co-ops with their own boiler-room access windows and HOA approval steps. We coordinate with building managers, work within shared-loop and quiet-hours limits, and provide the documentation a board usually wants before signing off on heating work.
Common Boiler & Radiator Repair Issues We Fix in Dupont Circle
- Banging, knocking, or hammering noises in pipes and radiators (water hammer)
- Cold or only partially warm radiators and uneven heating between floors
- Failed or stuck steam traps and air vents
- Boiler leaks, low water level, or pressure problems
- Aging cast-iron boiler at end of life — repair or replace?
- Hissing radiator valves and trapped air needing bleeding
What's Included
- Diagnosis and repair of water hammer and loud banging pipes
- Fixing cold or unevenly heating cast-iron radiators
- Steam trap testing, repair, and replacement
- Leak detection and repair on boilers, valves, and piping
- Low-water and low-pressure troubleshooting and correction
- Radiator bleeding and whole-system balancing
- Annual boiler tune-ups and safety inspections
- Honest assessment and replacement of aging cast-iron boilers
Explore our full Boiler, Radiator & Steam Heat Repair service, or see all HVAC services in Dupont Circle.
What It Costs
Most boiler and radiator repairs in Washington, DC fall between $200 and $1,000, depending on the part and the labor involved, while major repairs on older systems can run from $1,200 to $3,000 or more. An annual service and tune-up typically runs $200 to $500, and a full boiler replacement generally lands between $6,500 and $11,500. Every system is different, so call us for a free, no-obligation estimate before you decide anything.