Boiler Repair & Installation

On steam it is nearly always the vent on that radiator, blocked or painted shut, so the air inside has nowhere to go and steam cannot enter. On hot water it is usually air trapped at the high point of that loop, or a valve not opening. Either way it is a small part and an hour of work. What it is almost never is a boiler too small for the building, which is the answer that gets offered most often.

Because steam and liquid water are meeting in the same pipe at speed. The usual causes are a main that has sagged or lost its pitch so condensate pools in the low spot, a radiator tipped away from its valve, or wet steam leaving a boiler whose near-boiler piping is wrong or whose water needs skimming. Banging is not a quirk of old buildings to be lived with — it is a symptom with a short list of causes.

Far lower than most are found set. A house system distributes steam on ounces of pressure; a cut-out around a pound and a half with a cut-in under a pound suits the great majority. High pressure does not push heat further — it slows the steam down, keeps the boiler cycling on the control, and burns fuel to no purpose. Turning that setting down is often the first thing we do and it costs nothing.

Look at the boiler. A steam boiler has a sight glass with a visible water line and a pressure gauge reading in low single digits. A hot water boiler has a circulator pump or several bolted to the piping, an expansion tank, and a gauge showing both pressure and temperature. At the radiator, a small silver or brass vent on the side means one-pipe steam; a valve at each end and no vent usually means hot water.

Water is leaving somewhere. On steam, a failed trap or a leaking underground return line will keep the automatic feeder running, and every gallon of fresh water brings oxygen and minerals that eat the boiler from inside. On hot water, a weeping relief valve usually means the expansion tank has lost its air charge. Constant make-up water is the single fastest way to destroy a boiler, so it is worth chasing early.

Cast iron routinely outlives the people who installed it — thirty years and beyond is ordinary if the water chemistry was kept sane. Condensing units are more like fifteen to twenty and depend heavily on being serviced. The trigger for boiler replacement is usually a section leaking through or a conversion off oil, rather than age by itself.

Yes, and you generally should. Cast iron radiators are excellent emitters and there is no reason to skip them. On steam they set the size of the new boiler, so we measure the connected radiation before ordering anything. On hot water they open an option worth considering: large old radiators can often run at lower water temperatures, which is what makes them a reasonable match for a condensing boiler or a heat pump later on.

Yes. Boiler repair across our NJ counties and New York City, in single-family houses, multi-family buildings, schools and light industrial sites. Larger plant, steam traps at scale and packaged units are handled by the commercial boiler and steam team, who also carry service agreements for buildings that need scheduled attention through the season.