Oil Burner Service & Repair
Oil Burner Service & Repair in Suffolk County, NY.
This page covers oil-fired furnaces and oil-fired boilers — the burner, the fuel system, and the combustion side — for homes across the Hartworx service area. Residential only.
Call (631) 873-5844We service oil. We don't convert it.
Hartworx services and repairs oil burners. It does not do oil-to-gas conversions, and it does not swap heat exchangers. That is not a limitation we are apologizing for — it is the point. Plenty of homeowners on oil call an HVAC company and get a sales pitch for a conversion instead of a repair. This page is the opposite of that. If somebody's burner is down, the job is to get the burner running.
A company that does not sell conversions has no reason to talk anybody into one. When Hartworx says a burner is worth fixing, that is a repair recommendation and not a step in a sales process. Travis Hart is on the job, not a dispatcher, and he has worked in this trade since 2017.
Most HVAC companies won't service oil
A large share of the housing stock in this part of Suffolk County still heats with oil. Most heating and air conditioning companies out here will not touch an oil burner — they do gas and forced air, and an oil call gets handed off to whichever fuel dealer is on the tank sticker. That leaves a homeowner on oil with two options: the company that delivers their fuel, or nobody.
We service oil burners. That is a plain statement about how this trade works here, not a statistic. Someone picks up seven days a week, 7 AM to 10 PM — 9 AM on Thursdays. Most heating and cooling companies on Long Island close at 5. Call and we'll tell you honestly when we can be there.
Common oil burner problems
The reset button
When the burner locks out, the primary control is doing its job: it sensed that the flame did not light or did not stay lit, and it shut the fuel off on purpose. The reset button is there so you can try one more cycle. Pressing it once is reasonable. Pressing it repeatedly pumps unburned oil into the combustion chamber and turns a service call into a bigger problem — the chamber floods, the next firing is harder and smellier, and what was a nozzle or a filter becomes a mess. One reset, then call. We find what actually failed instead of resetting it until it quits for good.
The nozzle
The nozzle sprays the oil into a fine mist so it can burn. A worn or partially plugged nozzle gives a poor or smoky flame — the burner runs, the flame looks off, and soot builds up in the chamber and the flue passages. The nozzle is a consumable. It is a routine replacement item at every annual service, not a part you wait on until it fails.
Electrodes and ignition
The electrodes sit in front of the nozzle and throw a spark to light the oil spray. Cracked porcelain, a wrong gap, or a failed ignition transformer or solid-state igniter means the burner motor runs and the oil sprays but nothing lights — and the cad cell shuts it down. The electrodes are set to a specific gap and angle, and a burner that will not light often has ignition rather than a fuel problem.
The cad cell
The cad cell is the flame sensor — a light-sensitive eye that tells the primary control whether there is actually a fire in the chamber. If the cad cell is sooted over or has failed, it shuts down a burner that is otherwise fine, because the control cannot confirm the flame. A burner that lights and then shuts right back down often has a cad cell that cannot see the fire it is looking at.
Fuel pump and pressure
The fuel pump pulls oil from the tank and pushes it to the nozzle at a set pressure. A pump that has lost prime, a failed coupling between the motor and the pump, or incorrect pump pressure each change the spray pattern and the flame. A burner that ran fine yesterday and will not fire today often has a pump that lost prime or a coupling that stripped, and the fix is on the fuel side, not the ignition side.
Filters and fuel delivery
The tank filter and the inline filter keep dirt and sludge out of the pump and the nozzle. They clog with sludge from the bottom of a tank, especially after a delivery stirs it up. A burner that runs fine for a while and then quits is often a fuel delivery problem rather than a burner problem — the filter is restricting, the pump starves, and the flame drops out. Changing the filter is a repair, not a reason to replace the burner.
Air in the fuel line
When a burner runs out of oil, air gets into the fuel line and the pump loses prime. A delivery fills the tank but does not bleed the air out of the line — the pump cannot pull fuel with air in it. A burner that ran out of oil and will not restart after a delivery usually needs bleeding rather than parts. If the tank was very low, water and sludge may have been drawn in as well, and the filter may need changing.
Water and sludge in the tank
Condensation builds up inside a partly empty tank, and water sinks to the bottom where the fuel line draws. Water in the line does ugly things to a burner in cold weather — it can freeze at the filter, it can stall the pump, and it corrodes the inside of the line. A burner that quits after a cold snap sometimes has water at the tank bottom rather than a burner fault. The tank is the source of the problem; the fix is on the fuel side.
Soot and dirty flue passages
Combustion soot insulates the heat exchange surfaces — it coats the passages the hot gases travel through, so the heat stays in the exhaust instead of going into the house. A sooted burner costs fuel and runs hotter than it should. A proper annual cleaning brushes the flue passages, vacuums the combustion chamber, and cleans the blower wheel and the burner assembly. This is cleaning and servicing, not replacement — a sooted burner is a burner that missed its service, not a burner that is worn out.
Draft and the barometric damper
Draft matters on an oil appliance — the exhaust has to leave the building at the right rate, not too fast and not too slow. A barometric damper in the flue opens and closes to hold that draft steady. A damper that rattles or sits wide open suggests the draft is wrong, and a burner that smokes or soots up sometimes has a draft problem rather than a nozzle problem. Combustion is set with instruments, not by eye — we read the draft and the combustion numbers together.
A smell of oil in the house
If there is a strong fuel smell or any sign of combustion products in the living space, get out and call the fire department or the utility first. That instruction comes before every other instruction on this page. A faint oil smell when the burner runs may be a draft or a combustion problem we can diagnose, but a strong smell or visible smoke is a safety call, not a service call.
Annual oil service — why it actually matters on oil
Oil burners need annual service in a way that gas equipment does not. Oil combustion produces soot, the nozzle and the filters are consumables, and a burner that misses a year does not fail politely — it fails on the coldest night. A burner that has not been cleaned builds soot in the flue passages, the nozzle wears, the filter loads, and the combustion drifts out of adjustment until the flame is poor or the burner locks out.
A real annual oil service includes a new nozzle, the filters and strainer, the electrodes, cleaning the flue passages and the combustion chamber, checking pump pressure, checking draft, and setting combustion with instruments. The full version of this is on the seasonal tune-ups and inspections page.
Oil-fired boilers and oil-fired furnaces are different jobs
On an oil-fired boiler, the burner is one half of the system and the hydronic side — circulators, zone valves, controls — is the other. On an oil-fired furnace, the burner feeds a heat exchanger and a blower distributes the air. Hartworx works on both sides: the burner end, and the water side of a boiler or the air side of a furnace. The burner is the same kind of work either way.
About converting to gas — the honest answer
Hartworx does not do oil-to-gas conversions. There is no form to fill out, no quote to request, and no partner to be referred to. In the Town of Islip, new gas conversions must be performed by a licensed master plumber — that is a Town of Islip requirement, and it is why a homeowner in Islip asking an HVAC contractor for a gas conversion is asking the wrong trade. The rules differ by town, and this page only states the Islip fact. If your burner is down, call us. If you want a conversion, that is a different conversation with a different trade.
What happens on an oil service call
- 1.We ask what you are seeing first — when it started, whether it locks out, whether it ran out of oil, what the flame looks like if you can see it — and we put the burner through a full cycle rather than diagnosing it from a description.
- 2.We check the fuel side — filter, pump pressure, nozzle, electrodes, cad cell — and the combustion side with instruments, not by eye. Draft and combustion numbers tell us what the flame is actually doing.
- 3.We tell you what we found and what the options are before any work goes ahead. If it is a filter and a nozzle, that is what it is. If the burner needs a full cleaning, we say so. No work you did not agree to.
Where we work
Across Suffolk County — Ronkonkoma, Holbrook, Lake Ronkonkoma, Centereach, Sayville, Patchogue, and the towns around them, west to Deer Park and east to Coram. The full town list, grouped by town government, is on the service areas page.
Related services
- Boiler service & repair — the hydronic side of an oil-fired boiler.
- Heating repair — the broad no-heat page across every system type.
- Furnace repair & replacement — the air side of an oil-fired furnace.
- Seasonal tune-ups — annual oil service before the heating season.
- Thermostats & controls — the thermostat and wiring end of the system.
Questions about oil burner service and repair
Do you actually service oil burners, or do you hand it off?
We service oil burners directly. Most heating and cooling companies in this area do gas and forced air and hand an oil call to whichever fuel dealer is on the tank sticker. We do not. Travis Hart is on the job, and the burner gets put through a full cycle and checked with instruments, not diagnosed from a description over the phone.
My burner keeps shutting down and I keep hitting reset. Is that bad?
Pressing reset once is reasonable. Pressing it repeatedly pumps unburned oil into the combustion chamber and makes the next firing worse — it can flood the chamber and turn a service call into a bigger problem. The lockout is the primary control telling you the flame did not light or did not stay lit. Stop after one reset and call. We find which part failed — the nozzle, the electrodes, the cad cell, the filter, or the pump pressure — instead of resetting it again.
Do you do oil-to-gas conversions?
No. We service oil; we do not convert it. We do not do oil-to-gas conversions and we do not swap heat exchangers. There is no form to fill out and no partner to be referred to. In the Town of Islip, new gas conversions must be performed by a licensed master plumber, which is a different trade — so a homeowner in Islip asking an HVAC contractor for a gas conversion is asking the wrong trade.
Do I have to use my oil delivery company for service?
No. The company that delivers your fuel and the company that services your burner do not have to be the same. A fuel dealer's business is delivering oil; a service call is a different job. We work on the burner independently of whoever fills the tank, and we diagnose the burner rather than assuming the problem is a delivery issue.
How often does an oil burner need to be cleaned?
Once a year, before the heating season. Oil combustion produces soot, and the nozzle and filters are consumables that wear out. A burner that misses a year of service does not fail politely — it fails on the coldest night. A real annual service includes a new nozzle, filters, strainer, electrodes, cleaning the flue passages and chamber, checking pump pressure and draft, and setting combustion with instruments.
My burner ran out of oil and won't start after a delivery. Why?
When a burner runs out of oil, air gets into the fuel line and the pump loses prime. A delivery fills the tank but does not bleed the air out of the line — the pump cannot pull fuel with air in it. The burner usually needs bleeding rather than parts. If the tank was very low, water and sludge may also have been drawn into the line, and the filter may need changing.
Do you work on oil-fired boilers as well as oil furnaces?
Both. An oil-fired boiler has a burner and a hydronic side — circulators, zone valves, controls — and an oil-fired furnace has a burner feeding a heat exchanger with a blower distributing the air. We work on the burner end of both, and on the water side of a boiler and the air side of a furnace. The burner is the same kind of work either way.
Call and tell us what the burner is doing.
Whether it locks out, won't light, ran out of oil, or just smells off. A phone call is the fastest way to a real answer.
(631) 873-5844Thart@hartworxhvac.com
Fri–Wed 7 AM – 10 PM · Thu 9 AM – 10 PM
Or send a message through the contact form. Someone picks up seven days a week, 7 AM to 10 PM — 9 AM on Thursdays. Most heating and cooling companies on Long Island close at 5. Call and we'll tell you honestly when we can be there.
Oil burner service at a Suffolk County home
Real photo to be supplied
Rather send a message?
If your heat is out right now, call — that is faster. Otherwise tell us what the burner is doing and what kind of system it is on.