The first cold snap of the year is when a lot of homeowners find out something is off with the boiler. The system sat all summer, the thermostat finally calls for heat, and the baseboard in the back bedroom stays cold while the living room is fine. Or the pipes start banging at 5 in the morning. Neither one means the boiler is finished, but both mean something needs a look.
Hot water or steam: which boiler you have
Open the basement door and look at the boiler’s gauges.
Hot water is the standard for new installs. All Island Comfort describes it as water heated to roughly 140 to 180°F and pumped through baseboard, radiators or radiant floor tubing. It is more efficient and easier to zone. You will see a pressure gauge and one or more circulator pumps on the piping.
Steam is common in homes built before the 1960s, per All Island Comfort, and Service Experts in Hampton Bays calls it common in older Long Island homes. The boiler makes steam that rises to cast-iron radiators. You will see a sight glass showing the water level and a low-water cutoff.
The difference matters on the phone. Ask whether the company works on steam before you book.
Problems that bring a boiler tech out
These come from All Island Comfort’s list of the boiler problems it repairs most.
On hot water systems
- pressure too high or too low
- a leaking relief valve
- a failed circulator pump
- stuck zone valves, which cause air-bound zones or uneven heat
- expansion tank failure
- a failed aquastat or thermostat
On steam systems
- a failed low-water cutoff
- problems with the pigtail or the gauge glass
On either
- knocking or kettling noises, and sediment buildup
- short cycling
- leaks from the boiler body, or cracked cast-iron sections
Service Experts adds three signs from the homeowner’s side: rooms at noticeably different temperatures, new banging or whistling in the pipes, and a boiler that runs constantly without keeping the house warm.
A relief valve is a safety device. If it drips, the boiler is telling you the pressure is wrong. Never cap it, plug it or turn it so it stops. Call for service.
Before the technician gets there
Service Experts asks homeowners to do four things before a boiler visit: confirm the thermostat is set to heat, check that the boiler’s power switch or breaker has not tripped, note any error codes or indicator lights, and clear the area around the boiler. Writing down the pressure reading on the gauge helps too.
Hot water from the same boiler
Some boiler homes also get their hot water from the boiler, either through a coil inside it or an indirect tank beside it. All Island Comfort installs indirect water heaters paired with boilers, and Suffolk County’s licensing rules list tankless domestic water heating coils on oil burning equipment as work an HVAC restricted plumber may do. If you lose heat and hot water at the same time, tell the company. It narrows the search to the boiler or its burner.
When to stop repairing a boiler
All Island Comfort publishes a specific list of replacement signs:
- the boiler is 15 to 20 or more years old
- repairs are recurring or expensive
- the body leaks or a section of the heat exchanger is cracked
- fuel bills rise with no other cause
- some zones heat unevenly
- efficiency is under 80% AFUE
- parts are no longer available
Its lifespans: 15 to 30 years for a well-maintained gas or oil boiler, 30 or more for cast iron with annual service, 15 to 25 for steel-jacketed. A new residential boiler runs $6,000 to $12,000 or more installed, by its numbers. Service Experts adds safety issues such as carbon monoxide risk or visible corrosion.
For older homes, the Department of Energy rates low-efficiency systems at 56% to 70% AFUE and high-efficiency boilers at 90% to 98.5%.
Who may work on boiler piping
In Suffolk County, a restricted plumber’s license for HVAC, issued by the county, allows a technician to install and repair steam, water and fluid piping on heating systems, indirect waste pipes and humidifiers. Suffolk’s rules say direct connections to the water supply, waste or drainage systems and to any gas service must be done by a licensed master plumber.
In Nassau County, plumbers are licensed by the towns, cities and villages, not the county, per Nassau Consumer Affairs. If your boiler job involves gas piping or a new water connection, ask which local license covers it.