Heating and Cooling Questions From Long Island Homeowners
Last updated Reviewed by Waseem Shahzad, Lead Technician
The 45 questions we hear most, answered briefly. Each answer links to the page with the full detail, and questions about a particular town are on that town's page.
Heating
What should I do if my oil boiler stops working at night?
Check that the thermostat is calling for heat, the emergency switch at the top of the basement stairs is on, and the tank has oil. You can press the burner reset button once; if it locks out again, do not keep pressing it, because unburned oil can build up in the chamber. Call (631) 414-7141 for 24/7 service.
From: Heating Repair
Why are some of my baseboards cold while others are hot?
In a hot-water system this usually means air trapped in that zone, a zone valve that is not opening, or a circulator that has failed or weakened. Low boiler pressure can also leave upper floors cold. A technician can purge the air, test the zone valve and circulator, and check the expansion tank in one visit.
From: Heating Repair
Why is my gas furnace blowing cold air?
A furnace blowing cold air usually indicates that the blower fan is running while the burners have safely locked out. Common culprits include a dirty flame sensor, a failed silicon nitride hot surface igniter, or a tripped high-limit switch caused by a clogged filter. Call (631) 414-7141 for prompt diagnosis.
From: Heating Repair
Why does my furnace turn on and then shut off after a few seconds?
The most common cause is a dirty flame sensor: the burners light, the sensor cannot confirm the flame, and the control shuts the gas off for safety. Cleaning or replacing the sensor usually fixes it. If it keeps happening, the cause can also be poor grounding, a cracked ignitor or a venting problem, which a technician can test for.
From: Furnace Repair
Is it safe to keep resetting my furnace?
Not repeatedly. One reset to see whether the fault returns is reasonable, but pressing the reset button on an oil burner several times can flood the combustion chamber with oil, and repeated lockouts on a gas furnace mean a safety control is doing its job. Call for a diagnosis instead.
From: Furnace Repair
How do I know if my furnace heat exchanger is cracked?
You usually cannot see it yourself. Warning signs include soot around the furnace, a burner flame that flickers or changes when the blower starts, a carbon monoxide alarm, or a technician finding high CO readings. A cracked heat exchanger cannot be safely repaired, so the furnace should be shut down and replaced.
From: Furnace Repair
What causes loud banging sounds in baseboard heating pipes?
Loud banging or hammering in hydronic baseboard pipes is caused by air bubbles trapped in the heating loops, thermal expansion against wooden framing, or a waterlogged expansion tank allowing system water pressure to spike. Technicians bleed air from the zones, test the expansion tank, and service circulator pumps to restore quiet warmth.
From: Heating Repair
Is a yellow burner flame on my heating equipment dangerous?
Yes, a yellow or flickering burner flame indicates incomplete fuel combustion, which generates dangerous carbon monoxide gas and soot. Natural gas and propane burners should always produce a crisp, steady blue flame. Shut down your heating equipment immediately and call (631) 414-7141 for certified combustion analysis and flue testing.
From: Heating Repair
Why is water dripping from my boiler relief valve?
The relief valve opens when pressure gets too high. On hot-water systems that usually means the expansion tank has lost its air charge and is waterlogged, or the fill valve is letting in too much water. A dripping relief valve should be checked rather than capped, because it is a safety device.
From: Boiler Repair
Cooling
Why is my air conditioner blowing warm air?
Your air conditioner blows warm air when a failed run capacitor prevents the outdoor compressor from starting, a dirty evaporator coil restricts heat absorption, or refrigerant has leaked from the copper line set. Technicians test electrical components, check operating subcooling, and locate leaks before recharging. Call (631) 414-7141 for diagnostics.
From: Air Conditioning Repair
What causes water to leak around an indoor air handler?
Indoor air handler water leaks typically result from a clogged condensate drain line backed up with algae, a cracked primary drain pan, or a frozen evaporator coil that has melted. High summer humidity fills drain pans quickly. Technicians clear drain lines with pressurized nitrogen and install protective overflow float switches.
From: Air Conditioning Repair
My AC is leaking water through the ceiling. What do I do?
Turn the cooling off at the thermostat, catch the water and move belongings, and if water is near light fixtures or outlets, switch off that circuit at the panel. The usual cause is a clogged condensate drain or a frozen coil. Then call (631) 414-7141.
From: Emergency HVAC
Should I repair or replace my aging air conditioner?
Replace your air conditioner if it is over twelve years old, uses phased-out R-22 refrigerant, or requires repairs exceeding half its replacement value.
From: Air Conditioning Repair
How do technicians calculate the right AC size for a home?
Technicians determine proper air conditioner sizing through an ACCA Manual J load calculation, never by rough square footage alone. This engineering calculation accounts for wall and attic insulation R-values, window orientation, ceiling heights, duct static pressure, and local Long Island summer temperatures to select the exact tonnage and prevent short cycling.
Can I install air conditioning in a home without existing ducts?
Yes, homes without ductwork can be cooled efficiently using multi-zone ductless mini-split systems or concealed slim-duct ceiling air handlers. Small refrigerant line sets route through exterior walls without disturbing vintage plaster, woodwork, or flooring. Each indoor head provides independent temperature control. Call (631) 414-7141 to explore ductless options.
How long does a central air conditioning installation take?
Replacing an existing outdoor condenser and indoor air handler typically takes one full day, or about six to eight hours. Complex retrofits requiring new sheet metal fabrication, ductwork modification, or multi-zone ductless heat pump line sets generally require two business days. Call (631) 414-7141 for an in-home evaluation.
What is included in an AC tune-up?
Coil cleaning, clearing the condensate drain and testing the float switch, testing the capacitor under load, inspecting the contactor and wiring, checking refrigerant charge by superheat and subcooling, and measuring static pressure and temperature split. Every item is standard on our cooling visits, and you get the readings in writing.
From: HVAC Tune-Ups
Heat Pumps & Mini-Splits
Do heat pumps work effectively during freezing Long Island winters?
Yes, modern cold-climate inverter heat pumps operate efficiently down to -13°F and below. Rather than relying on inefficient electric strip heating, advanced variable-capacity compressors extract ambient thermal energy from freezing outdoor air and deliver full heating capacity throughout severe Long Island winter freezes. Call (631) 414-7141 to learn more.
From: Heat Pumps & Mini-Splits
How does a heat pump provide both heating and cooling?
A heat pump contains a four-way reversing valve that reverses refrigerant flow. In summer, it absorbs indoor heat and expels it outdoors like a standard air conditioner. In winter, the cycle reverses, extracting outdoor atmospheric heat and transferring it inside to provide comfortable, energy-efficient warmth throughout your home.
From: Heat Pumps & Mini-Splits
What is the difference between ducted and ductless heat pumps?
Ductless heat pumps use compact wall, floor, or ceiling air handlers connected to an outdoor condenser via small refrigerant tubing, providing independent room zoning without ductwork. Ducted heat pumps connect directly to existing central sheet metal ducts, replacing traditional furnace and AC setups with a single year-round electric system.
From: Heat Pumps & Mini-Splits
Can I keep my existing boiler when installing a heat pump?
Yes, many Long Island homeowners maintain their existing hydronic boiler or furnace as a dual-fuel hybrid backup. The cold-climate heat pump efficiently handles primary heating and summer cooling during typical seasonal weather, while your existing system remains connected for extreme sub-zero emergencies or supplemental comfort. Call (631) 414-7141 to evaluate hybrid options.
From: Heat Pumps & Mini-Splits
Can a heat pump replace my oil heat completely?
In many Long Island homes, yes. A correctly sized cold-climate heat pump keeps producing useful heat at the temperatures we see on the coldest nights. Whether a full changeover makes sense depends on insulation, ductwork and the load calculation, which is why many homeowners start with dual fuel and keep the oil boiler or furnace as backup.
What is dual fuel?
A dual-fuel system pairs a heat pump with your existing boiler or furnace. The heat pump carries most of the heating season and also cools in summer, and integrated controls switch to the oil equipment on the coldest nights. You keep a backup you already own while cutting how much oil you burn.
Can a ductless mini-split heat my Long Island home all winter?
A correctly sized cold-climate mini-split can. Current inverter models keep producing useful heat well below freezing, which covers the teens and single digits Long Island sees on the coldest nights.
How many indoor units do I need?
Usually one per room or open area you want to control. An open living and dining area can share one head, but bedrooms behind closed doors need their own. One outdoor unit can run several indoor units on a multi-zone system; we size each head to the room it serves rather than putting the largest unit everywhere.
Where does the outdoor unit go?
Usually on a pad or wall bracket at the side or back of the house, close to the indoor units to keep the line set short, with room for airflow and clear of snow drifts and roof runoff. Near the water we look for a spot sheltered from salt spray.
How is a mini-split maintained?
Rinse or vacuum the indoor unit filters every month or two during heavy use, and keep the outdoor unit clear of leaves and snow. Once a year a technician should clean the indoor coil and blower wheel, check the condensate drain and confirm operating pressures.
Costs & Financing
How much does it cost to replace central air on Long Island?
K2's planning range for replacing a central air conditioner on existing ductwork is $5,800 to $13,500. Where you land depends on the size of the system, its efficiency tier and the electrical work the new condenser needs. A Manual J load calculation sets the size, so you pay for the capacity the house needs.
How much does it cost to replace a gas furnace on Long Island?
K2's planning range for a gas furnace replacement is $3,500 to $8,500. The size and efficiency of the new furnace, the venting and how it connects to your existing ductwork set where the price lands. An all-new furnace system with new ductwork runs $8,500 to $12,000.
How much does a new boiler cost on Long Island?
K2's planning range for replacing a gas boiler is $7,500 to $16,000. Boilers cost more than furnaces because of the near-boiler piping, the venting or chimney liner, and the zone controls. An all-new boiler system with new piping and radiation runs $11,000 to $25,000.
What does an oil-to-gas conversion cost?
It depends on the equipment. A conversion burner on a sound cast-iron boiler costs much less than a new boiler, while a worn boiler is usually replaced with a gas unit. Removing or abandoning the oil tank is priced separately, and a buried tank costs more. We quote each part in writing.
How much does a heat pump cost on Long Island?
K2's planning range for replacing a heat pump is $6,000 to $15,000, and $12,500 to $20,000 for an all-new system. Cold-climate models that keep heating in a Long Island winter sit toward the upper end. The number of zones and the electrical work move the price more than the brand does.
How much does a ductless mini-split cost?
A ductless system is priced by the number of rooms (zones) it serves, the length of the refrigerant lines, the electrical work and the wall construction. A single-zone wall unit costs the least; multi-zone systems and ceiling cassettes cost more. We size each zone and quote the whole system in writing.
Are there rebates for heat pumps on Long Island?
Qualifying cold-climate heat pumps may be eligible for PSEG Long Island Clean Heat rebates. Rebates are claimed through a PSEG Long Island participating contractor or directly with PSEG Long Island. com.
Can I finance a new system?
Yes. K2 offers Rheem KwikComfort financing, with credit provided by Synchrony Bank and subject to credit approval. Terms depend on the application, so we do not quote monthly payments on the website. Ask about financing when we give you the written estimate, and apply before installation day.
Do you charge more for emergency calls?
After-hours, weekend and holiday visits can be priced differently from regular appointments. Ask when you call and we will tell you before the technician is dispatched, and you get the repair price before any work starts.
From: Emergency HVAC
How do I get an exact price for my home?
Call (631) 414-7141 or send the form. A technician looks at the existing equipment, the space, the ductwork or piping and the electrical panel, then gives you a written estimate before any work starts. The ranges on this page are for planning only and are not a quote.
Scheduling
Do you really answer the phone 24/7?
Yes. K2 answers calls 24 hours a day, including nights, weekends and holidays, for homes within about 15 miles of Deer Park. Call or text (631) 414-7141. We will ask what the system is doing, tell you what is safe to check and arrange the visit.
From: Emergency HVAC
How fast can a technician get to me?
It depends on the time, the weather and how many calls are waiting, so we give you a time window rather than a promise in minutes, and we let you know if it changes. No-heat calls and households with elderly residents, infants or anyone medically vulnerable go to the front of the queue.
From: Emergency HVAC
What should I check before calling about no heat?
Check that the thermostat is on HEAT with fresh batteries and set above room temperature, that the furnace or boiler power switch is on and the breaker has not tripped, and, on oil, that the tank is not empty. On a furnace, make sure the front panel is seated. If none of that helps, call.
From: Emergency HVAC
What should I do if I smell gas?
Leave the house right away, without touching light switches, the thermostat or anything that could spark, and call the gas utility or 911 from outside. Do not go back in until it has been declared safe. A gas smell is not something to diagnose yourself.
From: Emergency HVAC
When should I schedule a furnace or boiler tune-up?
Early fall, before the heat goes on for the season. Booking in September or early October means the work is done before the first cold week, when breakdown calls stack up, and parts are easier to get. Cooling equipment should be tuned up in spring, before the first heat wave.
From: HVAC Tune-Ups
How long does a tune-up take?
A typical residential tune-up takes roughly an hour to an hour and a half per system. Oil burners and boilers, heavily fouled coils or badly blocked drains take longer. A twenty-minute visit cannot include the measurements that make it a real tune-up.
From: HVAC Tune-Ups
Is a maintenance plan better than booking single tune-ups?
If you would book both the heating and cooling visits anyway, a plan usually works out better: it includes one combined heating and cooling visit each spring, plus a repair discount and priority scheduling on busy days. See the maintenance page for current plan options.
From: HVAC Tune-Ups
How long does a boiler or furnace replacement take?
A direct residential boiler or furnace replacement is typically completed within one to two days. Full oil-to-gas conversions or extensive hydronic near-boiler repiping may require two to three days. Our technicians maintain safe temporary heat solutions if work must span overnight during cold weather. Call (631) 414-7141.
From: Heating Installation
Still have a question?
Call or text us 24/7. We serve homes within 15 miles of Deer Park.
(631) 414-7141