NYC Heat Season Boiler Checklist: Getting an Apartment Building Ready for October 1

In New York City, heat season is not a weather forecast. It is a legal period. From October 1 through May 31, the owner of a residential building has to keep every apartment at a required indoor temperature, day and night, whether or not the boiler is having a good week. And a tenant who is cold no longer waits for the super to pick up. They file a 311 heat complaint, it lands at HPD, the city’s housing agency, and the building’s name is now on a list.

For a property manager or a building superintendent, that makes the first cold night in October a test the boiler passes or fails in public. The good news is that most first-night failures are not mysteries. A low water cutoff that stuck over the summer. A burner nobody tuned since last spring. A flue half-blocked by a bird’s nest or crumbling chimney liner. A heat timer still set to last year’s schedule. Each of these is something a pre-season visit finds in an afternoon, and each of them is a no-heat call at 11 PM if nobody looks.

This guide is written for apartment building boilers: the steam boiler in a pre-war walk-up, and the hot water boiler in a newer building or a converted townhouse. It covers what the law asks for, a checklist you can hand to your super, what the work costs, and how to decide when to stop repairing and start pricing a boiler replacement. If you run a smaller property on a furnace, most of the checklist still applies: the flue, the combustion test and the safeties work the same way. So does the timing: heating repair in New York is easy to book in September and hard to get in the first cold week of October, and furnace repair is no different.

What NYC Law Requires During Heat Season

The rules come from the city’s Housing Maintenance Code, and HPD enforces them. They are short enough to post on the boiler room door.

• Heat season: October 1 through May 31.
• Daytime, 6 AM to 10 PM: when the temperature outside drops below 55°F, the inside of every apartment must be at least 68°F.
• Overnight, 10 PM to 6 AM: the inside must be at least 62°F, no matter what the temperature is outside.
• Hot water, all year: HPD requires a constant minimum of 120°F, 365 days a year, not only during heat season.
• Heat complaint: a tenant calls 311 or files online. HPD contacts the building and, if heat is not restored, sends an inspector. A heat violation is Class C, “immediately hazardous,” with no grace period. If heat still is not restored, HPD’s Emergency Repair Program can hire its own contractor and bill the owner for the work plus fees. Buildings with a record of heat problems can also be selected for HPD’s Heat Sensor Program, which requires a temperature sensor in each apartment for up to four years.
• Penalties: since December 2023, a first heat violation carries civil penalties of $350 to $1,250 per day. A repeat violation at the same building within two consecutive heat seasons runs $500 to $1,500 per day. HPD also charges $200 for each inspection that finds a third or later heat violation in the same season.

Read the overnight rule twice. Many buildings still run an old setback schedule that drops the boiler hard at night to save fuel. If the apartments fall below 62°F at 3 AM, the building is out of compliance, even if nobody has complained yet. The same goes for the top-floor corner unit that never quite warms up: the law applies to every apartment, not to the average.

The boiler does not have to be broken for the building to be in violation. It only has to be too slow, too small, or too badly balanced to keep the coldest apartment at the required temperature.

When the Boiler Can’t Keep Up: Repair or Replace?

Every boiler gets to a point where the next repair is money spent on a machine that will fail again next winter. The trick is recognizing that point before it arrives in January. These are the signals that matter.

1. The boiler itself is leaking. A cracked cast-iron section, a leaking steel tube, water pooling under the boiler with no pipe leak above it. Controls, burners and pumps can be replaced; the pressure vessel is the boiler. Once it leaks, replacement is the realistic answer, and doing it on your schedule is much cheaper than doing it on the boiler’s.
2. The apartments are cold even when the boiler runs nonstop. First rule out the pipes, because a new boiler will not fix failed steam traps or air-bound risers (see step 6 above). If the distribution checks out and the boiler still cannot hold temperature on a cold day, it is undersized for the building as it is today, or it has lost so much efficiency that its real output is far below the nameplate.
3. The repair bills keep stacking up. A rough rule many owners use: when a single season’s repairs head past a third of what a replacement would cost, and the boiler is 25 years old or more, get a replacement price before you approve the next repair. Old steam boilers often last longer than that, so age alone is not the reason. Age plus a pattern of failures is.
4. It still burns oil, or it was sized for a different century. No. 6 heating oil has been banned in the city since 2020, and No. 4 oil is banned in boilers from July 1, 2027. For a building still burning No. 4, this winter is the last heat season on that fuel, and the conversion needs to be planned now. Many older buildings also run boilers that are far bigger than the building needs, sized decades ago with generous margins and never revisited. An oversized boiler short-cycles, wastes fuel and wears out its controls. Replacement is the chance to size it properly.
5. The building faces Local Law 97. If the building is large enough to be covered, its carbon emissions are now capped, and the boiler is usually the biggest source. A replacement decision made today should be made with those limits in mind. More on that in the paperwork section below.

A new boiler on a building with broken steam traps is an expensive way to keep the same complaints. We check the pipes before we quote the boiler.

Timing matters as much as the decision. A boiler replacement in an occupied building is best done between June and September, when the building only needs hot water. Once heat season starts, a replacement means a temporary boiler or a planned outage, and the permit process takes weeks either way. If this winter’s signs are pointing toward replacement, the right move is to get the site survey and the boiler replacement quote in hand now, keep the old boiler running safely through the season, and schedule the work for spring. For mixed-use and commercial properties, the same planning applies to the rest of the building’s equipment; our commercial HVAC installation team handles those projects.

The Paperwork: Inspections, Permits and Local Law 97

A boiler in a New York apartment building comes with its own paper trail. Here is what a property manager should have on the calendar.

• Annual boiler inspection report. Low-pressure boilers in residential buildings with six or more apartments, and in commercial and mixed-use buildings, must be inspected every calendar year, whatever their size. The owner hires the inspector: a DOB-approved boiler inspector or an authorized boiler insurance company. The report has to be filed in DOB NOW: Safety within 14 days of the inspection, and any defects must be corrected within 90 days. Late filing costs $50 per month per boiler, up to $600; not filing costs $1,000 per boiler. Buildings with five or fewer apartments are exempt, and so is a boiler inside one apartment that heats only that apartment. High-pressure boilers are inspected twice a year by an authorized insurance company.
• DOB boiler permit for a replacement. Replacing a boiler is filed in DOB NOW: Build as Boiler Equipment work, and the permit is issued only to a Licensed Master Plumber or a Licensed Oil Burner Installer. Above 1 million Btu/h of input, a registered engineer or architect also has to file plans. The new boiler cannot go into service until DOB inspects it; once that first inspection passes, no separate annual report is needed for that year.
• Gas work. The new boiler’s gas connection, and any upgrade to the gas service it needs, is permitted plumbing work. Gas line work is performed under an NYC Master Plumber license, with full DOB permits filed. Separately, Local Law 152 requires a building’s gas piping to be inspected by a Licensed Master Plumber at least every four years; buildings in community districts 4, 6, 8, 9 and 16 are due by December 31, 2026.
• Air permits. Boilers rated at 350,000 Btu/h and up also need a DEP registration, renewed every three years, and several smaller boilers in the same building count together toward that threshold. Very large boilers, 4.2 million Btu/h and above, need a DEP work permit and a certificate of operation instead.
• Local Law 97. Buildings over 25,000 square feet now have yearly carbon emission limits. For apartment buildings the limit drops by roughly 40 percent in 2030, and the fine is $268 for every metric ton over the cap. Reports are due May 1 each year. Many buildings with rent-regulated apartments follow a list of required measures instead, and most of them are boiler-room work: repairing heating leaks, maintaining the heating system, insulating heating and hot water pipes, fixing steam traps, venting steam mains and risers, and installing indoor and outdoor sensors with boiler controls. In other words, the checklist above is also emissions work.

None of this has to be a scramble. A building on a maintenance plan gets the pre-season service, the safety checks and the written records on a schedule, so the inspection finds a boiler that was already looked after. We work on boiler rooms across the city, from pre-war walk-ups in Brooklyn to co-ops and mixed-use buildings in Manhattan, and the paperwork looks the same in both.