Boiler Repair on Long Island
Last updated Reviewed by Waseem Shahzad, Lead Technician
Steam and hot-water boiler repair, gas and oil, for homes within 15 miles of Deer Park.
Boilers heat a large share of older Long Island homes, from cast iron radiators in Babylon Village to baseboard loops in post-war ranches. K2 repairs gas and oil boilers, steam and hot water, from our Deer Park shop for homes within about 15 miles. We answer no-heat calls 24/7, and you get the cause and a price before any work starts.
Common Problems We Fix
Boilers fail differently from furnaces, and steam fails differently from hot water. What we fix most often:
- No heat, burner will not fire. On oil, a clogged nozzle or filter, a failed ignition transformer or a lockout at the primary control. On gas, a failed igniter or pilot assembly, flame sensor or gas valve.
- Some rooms or zones cold, others fine. A failed zone valve or circulator pump, or air trapped in the loop on a hot-water system.
- Pressure relief valve dripping or pressure climbing. Usually a waterlogged expansion tank or a failing fill valve on hot-water systems.
- Banging pipes on a steam system. Often a pressure control set too high, water trapped in pipes that have lost their pitch, or failed radiator vents.
- Low-water cutoff tripping. The most important safety device on a steam boiler. It needs testing and flushing, and a cutoff that trips repeatedly is telling you something.
- Leaks at the boiler. A leaking fitting, pump seal or relief valve is repairable; water weeping from the boiler sections themselves usually is not.
- Soot, smoke or a puff-back on an oil boiler. That calls for an immediate burner and combustion check.
What Happens on the Visit
- Tell us what you see. Steam or hot water, the pressure or water level in the sight glass, whether the burner fires and which rooms are cold. That decides what we bring.
- Safety checks. Venting, flue draft and the low-water cutoff come first.
- Diagnosis. We check the burner, controls, circulators, zone valves, expansion tank and relief valve on hot-water systems; on steam, the water line, pressure control, cutoff and main vents.
- A price before work. You hear the cause, the fix and the price first.
- Repair and test. We bring the system up to temperature, confirm every zone heats and, on oil, take a combustion reading so the burner runs clean.
What Affects the Price
Every boiler repair is quoted after diagnosis. What moves the price:
- Steam or hot water. Steam systems involve vents, water levels and piping pitch; hot-water systems involve pumps, valves and the expansion tank.
- The part. A zone valve head, a circulator, a burner component and a gas valve are very different in cost.
- Fuel. Oil burners need a nozzle, filter and combustion setup that gas boilers do not.
- Draining and refilling. Some repairs need the system drained, refilled and purged of air, which adds time.
- Age. Controls for older boilers can take longer to source.
Plan members get a repair discount and priority scheduling through our maintenance plans.
Repair or Replace?
Well-maintained cast iron boilers often last 25 years or more, so repair is usually the right answer for pumps, valves, controls and burner parts. Replacement is worth discussing when:
- the boiler sections are leaking or cracked;
- the boiler is past 25 to 30 years and parts are getting hard to find;
- fuel use is high and the burner cannot be tuned to burn efficiently; or
- you want to move from oil to gas, which is often done when an oil boiler is replaced. See oil-to-gas conversion.
Our online Cost Estimator gives a gas boiler replacement planning range of roughly $7,500 to $16,000; your quote depends on the system and the piping. For new equipment, see heating installation. Financing is available through Rheem KwikComfort, with credit provided by Synchrony Bank, subject to credit approval. See financing for how it works.
Brands We Install and Service
Our technicians work on all major brands. The ones we install most often (see all brands):
- Rheem
- Fujitsu
- Trane
- Bosch
- Daikin
Areas We Serve
We serve homes within about 15 miles of our shop at 60 S 2nd St, Unit V in Deer Park, across western Suffolk and eastern Nassau County. Local pages for the towns we cover:
- Deer Park, NY
- Huntington, NY
- Babylon, NY
- Islip, NY
- Smithtown, NY
- Commack, NY
- Hicksville, NY
- Levittown, NY
- Massapequa, NY
- Farmingdale, NY
- Bay Shore, NY
- Brentwood, NY
- Central Islip, NY
- Sayville, NY
- Hauppauge, NY
- West Babylon, NY
- North Babylon, NY
- Lindenhurst, NY
- Amityville, NY
- Copiague, NY
- Dix Hills, NY
- Melville, NY
- Huntington Station, NY
- Plainview, NY
- Bethpage, NY
- Massapequa Park, NY
- Syosset, NY
- Wyandanch, NY
- Wheatley Heights, NY
- West Islip, NY
- Brightwaters, NY
- Elwood, NY
- Old Bethpage, NY
- Greenlawn, NY
- South Farmingdale, NY
- Islip Terrace, NY
- East Islip, NY
- Kings Park, NY
- Northport, NY
- Ronkonkoma, NY
- St. James, NY
- Oakdale, NY
- Holbrook, NY
- East Meadow, NY
- Oyster Bay, NY
- Cold Spring Harbor, NY
- Lloyd Harbor, NY
- Bohemia, NY
- Jericho, NY
- Woodbury, NY
- Brookville, NY
- Wantagh, NY
- Seaford, NY
- Bellmore, NY
- Plainedge, NY
- Islandia, NY
- Centerport, NY
- Great River, NY
- Nesconset, NY
- Lake Ronkonkoma, NY
- West Sayville, NY
- North Bellmore, NY
- Bayport, NY
- East Northport, NY
Popular Areas for Boiler Repair
- Boiler Repair in Deer Park, NY
- Boiler Repair in Huntington, NY
- Boiler Repair in Babylon, NY
- Boiler Repair in Commack, NY
- Boiler Repair in Dix Hills, NY
- Boiler Repair in Bay Shore, NY
- Boiler Repair in Massapequa, NY
- Boiler Repair in Farmingdale, NY
- Boiler Repair in Islip, NY
- Boiler Repair in North Babylon, NY
- Boiler Repair in Huntington Station, NY
- Boiler Repair in East Islip, NY
- Boiler Repair in Melville, NY
What Our Customers Say
"Waseem is excellent. He checked my hearing system, diagnosed the problem and fixed the whole system. Now the heat is working excellently. I am high recommending this company to any person’s house. He is very thorough and spent as much as was needed to repair the heat. We are very thankful. He is excellent. Thank you so much to your company."
"This is my second (distinct) job with K2 HVAC and I couldn't be more appreciative of their prompt and quality services. The first job (a replacement of my heating unit) was handled excellently by Shelby and the second (a replacement of my hot water unit) was amazingly handled by Waseem. The backend customer support is fantastic too, as Sadia is ever responsive by text and phone call. All said, I recommend their services wholeheartedly!"
"This was my first time using K2 Cooling & Heating, and I couldn't be happier with the experience. Waseem arrived on the scheduled day right on time and took the time to listen carefully to the issues I was having with my HVAC unit before beginning any work. He quickly diagnosed the problem and explained everything clearly in a way that was easy to understand. His professionalism, knowledge, and attention to detail were outstanding. He fixed the issue efficiently and made sure everything was working properly before he left. It's refreshing to work with someone who genuinely cares about providing excellent customer service. I highly recommend Waseem and K2 Cooling & Heating to anyone looking for honest, reliable, and knowledgeable HVAC service. I will definitely be using them again in the future!"
Boiler Repair: Frequently Asked Questions
Do you repair both steam and hot-water boilers?
Yes. K2 repairs steam and hot-water boilers, gas and oil. They have different problems: steam systems need the low-water cutoff, pressure control and vents checked, while hot-water systems depend on circulator pumps, zone valves and the expansion tank. Tell us which you have when you call (631) 414-7141.
Why are some rooms cold while others are warm?
On a hot-water system the usual causes are a failed zone valve, a circulator pump that is not running, or air trapped in the loop. On steam, it is often a failed radiator vent or a main vent that is not letting air out. Each is a repair, not a reason to replace the boiler.
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.
Why do my radiator pipes bang?
Banging on a steam system is usually water trapped in pipes that have lost their pitch, a pressure control set higher than a home system needs, or failed vents. Correcting the pressure setting alone often quiets it and saves fuel. Hot-water systems can also knock when air is trapped in the pipes.
How often should a boiler be serviced?
Once a year, ideally in early fall before the heat goes on. Oil boilers need a new nozzle and filter and a combustion test each year, and steam boilers need the low-water cutoff flushed and tested. Our maintenance plans include the annual visit and add priority scheduling.
Should I replace my oil boiler with gas?
It can make sense if natural gas is available on your street and the oil boiler is old or failing. The conversion involves a new gas service from the utility, a new or converted boiler and dealing with the oil tank. Our oil-to-gas conversion page explains what is involved and what affects the cost.
Book Boiler Repair With K2
Call or text (631) 414-7141 any time, or send the form and we will call you back to schedule. You get the cause and the price before any work starts. Financing is available through Rheem KwikComfort, with credit provided by Synchrony Bank, subject to credit approval.
Considering a heat pump for a baseboard house? See air-to-water heat pumps and dual-fuel heat pumps.
Boiler repair in your town: see boiler repair across Long Island.
Boiler will not fire? See safe checks and when to call.
Related services: furnace repair, 24/7 emergency service, boiler and furnace tune-ups, oil-to-gas conversion and water heaters. Guides: the boiler maintenance checklist, combi vs. conventional boilers and boilers in winter.
Troubleshooting before you call
Recent boiler repair jobs

One of three boiler zones not heating
Dix Hills · Boiler Repair · October 2026
A three-zone gas boiler with one cold zone. We bled the air from all three zones, replaced the air bleeder and four caps, and cleaned the boiler.

Boiler leak and no hot water: valves, tank and coil replaced
Huntington · Boiler Repair · September 2026
A boiler that had lost hot water and was leaking. We replaced the failed valves, the expansion tank and the leaking domestic hot water coil.

Leaking boiler: expansion tank and air bleeder replaced, plus a tune-up
Dix Hills · Boiler Repair · March 2026
A leaking boiler. We replaced the expansion tank and the air bleeder, bled the air from the system and did the yearly boiler maintenance.
More boiler repair jobs: Boiler inspection and performance evaluation before a home sale (Deer Park) · Zone valve, expansion tank and air vent replaced on an aging boiler (Deer Park) · No heat in one unit: thermostat and leaking air bleeder replaced (Islip) · Expansion tank, relief valve and air bleeder replaced (Woodbury)
Watch: You're Heating Your Home With THIS Inside the System
Would you want this circulating through your heating system? What you're seeing is dirty boiler water removed during a heating system service.
Related Guides
Written by our technicians for Long Island homeowners:
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Contact K2 Cooling & Heating today for a free upfront estimate or 24/7 emergency service.