In Suffolk County about 44 percent of occupied homes heat with fuel oil. In Brooklyn the figure is about 7 percent, and in Staten Island about 4 percent. In the Bronx about 21 percent use oil and roughly half use utility gas. A heating system inspection in New York therefore starts with a different question depending on where the house is: a gas boiler, an oil burner and a tank, a one-pipe steam system from the 1920s, or electric heat. These Census figures count apartments as well as houses, but the pattern is why one inspection does not fit every address.
Our firm, Inspecwise, is licensed as a home inspector by New York State, holds InterNACHI certification and is based in South Ozone Park, Queens. This guide lists what the state Standards of Practice require an inspector to check in a heating system, what they leave out, and what to ask about each fuel. A home inspector is not a heating contractor or an engineer, and the questions the Standards leave out belong to the trades named below.
Heating fuels in New York by county
The Census Bureau’s American Community Survey asks every occupied home how it is heated. The table shows the three largest groups; propane or tank gas, wood, coal, solar, other fuels and no fuel make up the rest.
| County | Fuel oil | Utility gas | Electricity |
|---|---|---|---|
| Suffolk County | about 44% | about 41% | about 9% |
| Westchester County | about 28% | about 52% | about 14% |
| Nassau County | about 26% | about 62% | about 7% |
| The Bronx | about 21% | about 52% | about 18% |
| Manhattan (New York County) | about 15% | about 49% | about 28% |
| Queens | about 10% | about 74% | about 10% |
| Brooklyn (Kings County) | about 7% | about 72% | about 14% |
| Staten Island (Richmond County) | about 4% | about 85% | about 7% |
These are survey estimates, so we round them and avoid ranking counties whose figures are close. The broad pattern is not close. Oil is a large share in Suffolk, Westchester and Nassau and a small one in Brooklyn and Staten Island, where utility gas dominates. Because the figures include apartments, the share among houses can differ; the point for a buyer is to know which fuel your house uses and what that fuel requires. Our pages for Suffolk, Nassau, Westchester and each borough go into the local housing stock.
What the Standards require in a heating system inspection
The Standards (19 NYCRR 197-5.10) set the floor for every fuel. The inspector describes the type of fuel, heating equipment and distribution system; operates the system using the thermostat; opens readily accessible panels provided for routine homeowner maintenance; and reports on the condition of normally operated controls and components, visible flue pipes and dampers, a representative number of heat sources in each habitable space, fixed supplementary heat units, and visible components of vent systems, flues and chimneys.
| The inspector does | The inspector is not required to | Who covers the rest |
|---|---|---|
| Operate the system from the thermostat | Operate a system that does not respond to the thermostat or has been shut down | The seller, to turn it on; a heating contractor |
| Open readily accessible, homeowner-maintenance panels | Remove covers or panels that are not readily accessible, or dismantle equipment, controls or gauges | A heating contractor on a service visit |
| Report on visible flues, vents, dampers and chimneys | Look inside chimney flues | A chimney specialist |
| Report on a representative number of heat sources in each habitable space | Evaluate the capacity, adequacy or efficiency of the system | A heating contractor; an energy auditor |
| Describe the fuel, equipment and distribution system | Evaluate heat exchangers, or the type of material in insulation or wrapping on pipes, ducts, jackets and boilers | A heating contractor; a certified asbestos professional for suspect wrapping |
| Report the visible condition of controls | Test for gas leaks or carbon monoxide, or determine clearance to combustibles or combustion air | The gas utility; a heating contractor |
| Report on fixed supplementary heat units | Test gas logs, built-in gas appliances, space heaters or radiant in-floor and in-ceiling systems | The relevant installer |
One more limit matters in a heating system inspection. The Standards also say the inspector need not activate a system when ambient temperatures or other circumstances are not conducive to safe operation or may damage the equipment. A boiler inspected in July may be listed as not operated, with the reason, as the Standards require. Our guide to a winter home inspection covers what changes in cold months.
Steam, hot water, forced air, oil, gas, electric: what to ask
| System or fuel | What it is | What to ask the seller | Who looks further |
|---|---|---|---|
| One-pipe steam | The steam rises to each radiator and the condensate drains back down the same pipe. The Department of Energy’s Building America Solution Center says venting is critical in these systems. | Age of boiler; recent service; any radiator that stays cold or knocks; whether pipe wrap has been replaced | A steam heating specialist; an asbestos professional for suspect wrap |
| Two-pipe steam | Steam goes in one pipe and condensate returns by a second; the system relies on steam traps. | Same, plus when traps were last checked | A steam heating specialist |
| Hot-water boiler | A boiler heats water that is sent to radiators, baseboard or radiant floor loops. | Boiler age; service records; zones and thermostats | A heating contractor |
| Forced-air furnace | A furnace heats air that moves through ducts to each room. | Furnace age; filter and service records; any rooms that are hard to heat | A heating contractor |
| Fuel oil | A burner, a tank and delivery. Boiler or furnace. | Tank location, age and history; delivery company; any past spill, leak or removal | An oil-tank specialist; an oil burner technician |
| Utility gas | A gas boiler or furnace connected to the gas utility’s service. | Appliance age; last service; any gas odor or utility visit | A licensed plumber for gas piping; the utility |
| Electric | Baseboard, in-wall or radiant heat, or a heat pump. | Panel capacity; which rooms are heated by which unit; any added circuits | An electrician |
The seller’s Property Condition Disclosure Statement asks whether there are or have ever been fuel storage tanks above or below ground on the property, and about known material defects in the heating system, hot water heater and chimney, fireplace or stove. Read the answers before the visit. The property condition disclosure guide walks through the form.
Steam heat in a pre-war house
Single-pipe steam, according to the Department of Energy’s Building America Solution Center, is commonly found in older buildings, especially those built before 1970. In such a system steam is generated in the boiler and travels through pipes that shrink with distance. In each radiator it gives up its heat and condenses, then drains back to the boiler through the same pipe it came up. Venting of steam lines is critical: only with properly sized, working air vents will steam reach every radiator at about the same time. Two-pipe systems use steam traps instead.
The inspector operates the system from the thermostat and reports the visible condition of the boiler, controls and piping. The Standards do not ask for an opinion on balance, efficiency or the heat exchanger. If a radiator the inspector checks is cold while the others are hot, the report notes it and a steam heating specialist works out why.
Steam pipes in older houses may be wrapped. The EPA’s list of places asbestos may be found includes steam and hot-water pipes with an asbestos coating or blanket, and oil and coal furnaces with asbestos insulation; the agency says exposure generally requires that the material be disturbed or damaged. The Standards say an inspector is not required to evaluate the type of material in pipe or boiler wrapping. Before any renovation or repair, the owner must have a certified New York State asbestos inspector survey the affected building or portion of it, according to the Labor Department. See our asbestos inspection post and the pre-war home inspection guide.
Oil heat: the burner, the tank and the delivery paperwork
A fuel oil system has three parts the inspector treats differently. The burner and boiler or furnace are operated and reported on as above. Fuel storage and distribution components that are visible are within the plumbing section of the Standards. But concealed spaces and underground items, including underground storage tanks and any underground indications of their presence, whether abandoned or otherwise, are not required to be observed. A buried tank is therefore a separate question; see our oil tank inspection post.
The city’s Department of Consumer and Worker Protection gives oil customers practical advice: check the delivery truck for an up-to-date DCWP seal, get a written contract with costs, delivery schedule and gallons promised, check your tank gauge before and after filling and compare it to your receipt, and do not ignore storage tank rust, corrosion or other signs of damage. When you buy, ask the seller for the delivery company’s name and a year of receipts.
New York City’s heating-oil grade rules are about larger buildings. The Department of Environmental Protection’s 2011 announcement described the target as about 10,000 boilers in larger buildings that burn grades No. 4 and No. 6, and said every new boiler permitted by the city would have to burn No. 2 oil, the cleanest form of heating oil, or an equivalent. The announcement set No. 6 to end by 2015 and No. 4 by 2030. In February 2023 the City Council passed legislation that, according to its press release, would ban No. 4 in boilers outside city-owned buildings after July 1, 2027; we did not read the enacted text, so check the current date with DEP. If your building has a large boiler, ask the seller and DEP which grade it burns. For a one- to three-family house with a typical oil burner, the practical question is service history and the condition of the tank.
Gas heat: piping, shut-offs and who inspects what
The gas supply system is outside the required inspection; the Standards say the inspector is not required to observe and report on it for materials, installation or leakage, or to test for gas leaks. In New York City, gas piping has its own law. The Department of Buildings says periodic gas piping inspections by a Licensed Master Plumber, at least once every four years, apply to all buildings except one- and two-family homes and other buildings in occupancy group R-3. The DOB page lists the exempt Department of Finance building classes: A0 to A9, B1, B2, B3, B9 and a few others. The three-family walk-up class, C0, which the city’s tax-lot data uses for three-family houses, is not on that list. So a one- or two-family house is exempt, and a three-family building is a case to check on DOB’s address lookup before you assume. If your building is covered, ask the seller for the latest filing.
If you smell gas, the Department of Housing Preservation and Development advises opening nearby windows, going outside and calling 911. The Consumer Product Safety Commission adds a rule for any home: never use gas appliances such as ranges, ovens or clothes dryers to heat your home.
Chimneys, flues and carbon monoxide
Carbon monoxide comes from incomplete burning of fuels including oil, wood and natural gas, according to the Consumer Product Safety Commission, which advises having the heating system professionally inspected and serviced every year, with chimneys and flues checked for blockages, corrosion and disconnections. A home inspection does part of that: the inspector reports on visible vents, flues and chimneys but not on flue interiors, and does not test for carbon monoxide or determine combustion air. The Building America guide to gas-fired boilers describes backdrafting, where combustion gases spill down into the room instead of going out the flue, and says running several exhaust fans, the dryer and the fireplace together can cause it. Whether a particular system backdrafts is a heating contractor’s test, not the inspection.
A carbon monoxide alarm is no substitute for maintaining the appliances, the CPSC says. For the alarm rules for New York homes, see smoke and carbon monoxide alarms in New York homes; for the chimney itself, see our chimney inspection post. One city rule is worth knowing: HPD says kerosene heaters and propane space heaters are illegal in New York City.
Buying a two- or three-family house: heat for tenants
If you will rent out a unit in New York City, the heating system becomes a legal obligation. The Department of Housing Preservation and Development says building owners are legally required to provide heat and hot water to their tenants. Heat is required from October 1 to May 31: when the outside temperature is below 55 degrees, inside temperatures must be at least 68 degrees between 6 a.m. and 10 p.m., and at least 62 degrees overnight regardless of the outside temperature. Hot water must be provided 365 days a year at a constant minimum of 120 degrees. The page speaks of building owners and tenants without a size exception; how it applies to a particular small house is a question for your attorney. Our two- and three-family home inspection page covers what is different about buying one.
A worked example: a 1925 two-family in Queens with a steam boiler
This case is invented for illustration and does not describe a house we inspected. The seller’s statement says the heating system has no known defects and that there is no fuel tank on the property.
- In the basement the inspector finds a one-pipe steam system with an oil burner. The inspector operates it from the thermostat, reports that the radiators in two rooms stay cold, and lists the boiler’s visible controls and flue connection.
- The pipes leaving the boiler are wrapped. The report records the wrapping and notes that the inspector did not evaluate the material.
- The inspector sees a capped fill pipe and a vent pipe at the side of the house. The report says a fuel tank may be underground and that underground items are outside the inspection, and recommends a tank search.
- The buyer asks for oil delivery receipts and service records, books a steam heating specialist for the cold radiators, and an asbestos professional before any boiler replacement.
- The buyer’s attorney raises the tank question with the seller, because the disclosure form asks if tanks exist or ever did.
The inspection found the questions; the specialists answer them.
Questions about heating system inspection
Can a home inspector tell me how much life is left in a boiler?
No. Remaining life of any system, and the capacity, adequacy and efficiency of a heating system, are outside what the Standards ask the inspector to determine. A heating contractor can give an opinion from the unit’s service history.
Will the inspector test for gas leaks or carbon monoxide?
No. The Standards list testing for gas leaks or carbon monoxide among the things an inspector is not required to do, and they exclude the gas supply system. Tell the gas utility if you smell gas, and call 911.
Is one-pipe steam heat a problem?
Not by itself. The Department of Energy’s Building America Solution Center says single-pipe steam is commonly found in older buildings, especially those built before 1970, and that venting is critical. The inspector reports condition; a steam specialist balances and repairs the system.
Does a house that heats with gas still need an oil tank check?
Possibly, if it ever burned oil. The state’s disclosure form asks whether there are or have ever been fuel storage tanks on the property, and the Standards do not require the inspector to find underground tanks. Ask the seller, and see our oil tank inspection post.
Do New York City’s heating oil rules affect a one-family house?
DEP’s 2011 rules were aimed at about 10,000 boilers in larger buildings burning No. 4 or No. 6 oil, and required new boilers to burn No. 2 oil or an equivalent. Ask DEP if your building has a large boiler.
Does NYC’s gas piping inspection law apply to my two-family house?
No. The Department of Buildings says the periodic gas piping inspection applies to all buildings except one- and two-family homes and other R-3 buildings. A three-family building is not on its exempt list, so check the address with DOB.
Who has to provide heat to tenants in a two-family house?
HPD says building owners are legally required to provide heat and hot water to their tenants, from October 1 to May 31 for heat. How that applies to your house is a question for your attorney.
About the figures
Heating-fuel percentages are Census Bureau estimates for 2020 to 2024 (American Community Survey, table B25040, occupied homes, by county) and carry margins of error.
Booking an inspection that includes the heat
Tell us the fuel and the kind of system when you book, and ask us to confirm that the heat can be run during the visit. Service covers the five boroughs, Nassau, Suffolk and Westchester, plus other areas on request, and the report can be discussed in English, Urdu, Punjabi or Hindi.
Questions first? Call 718-925-7071.