Most no heat in house calls come down to five things: a thermostat set wrong, a tripped breaker, a clogged filter, an empty oil tank, or a burner stuck in lockout. Run the five checks below in order. If heat is not back in 15 minutes, call 631-591-2289 and we will send a technician.
What No Heat in the House Usually Means
Match what you are seeing before you touch anything. It tells you how worried to be.
| Symptom | Likely cause | Urgency |
|---|---|---|
| System completely dead, no fan, no clicks | Tripped breaker, bumped power switch, or dead thermostat | Check it yourself first |
| Burner clicks or hums but never fires | Ignition failure, or an oil burner in lockout | Call today |
| Runs but the air is cold or lukewarm | Clogged filter, failed igniter, or dirty flame sensor | Call today |
| No heat plus a gas smell or smoke | Possible leak or combustion problem | 911 and National Grid first |
| Some rooms warm, others cold | Zoning or airflow problem | Can usually wait a day |
What to Check Yourself Before You Call
These five checks take about ten minutes and cost nothing. They fix a surprising share of the no heat calls we run.
1. Thermostat first (2 minutes). Set the mode to Heat, not Auto or Cool. Raise the setpoint 5 degrees above room temperature. If the screen is blank, swap the batteries. Wait three minutes, because many systems have a built-in start delay.
2. Check the filter (2 minutes). A packed filter can shut a furnace down on its high-limit safety before the house ever warms up. Hold the filter up to a light. If you cannot see light through it, replace it.
3. Breaker and power switch (3 minutes). Look for a tripped breaker in the panel and reset it once. Then find the service switch near the furnace or boiler. It looks like a light switch, and it gets bumped off more often than anyone admits. If the breaker trips a second time, leave it off and call, because repeated trips mean an electrical fault.
4. Listen for the start attempt (2 minutes). Turn the thermostat up and stand by the equipment. A click with no flame points to ignition, and a hum with no fan points to a motor or capacitor. Silence points to power or controls. Tell us what you heard when you call, because it shortens the diagnosis.
5. Note any error code (1 minute). Many furnaces flash an LED code behind a small window, and oil burners show a red reset button when they lock out. Write down the code or the light pattern. Press an oil burner reset button once at most, because repeated presses flood the chamber with unburned oil and turn a small repair into a big one.
Call Now or Can It Wait
Call now, any hour:
- No heat and the house is below 55 degrees
- Anyone elderly, an infant, or a medical condition in the home
- A breaker that trips again after one reset
- A burner that locked out again after one reset
- Water leaking from the boiler along with the no heat
- Any gas smell, oil smell, or smoke: safety steps first, then the utility, then us
It can wait for a daytime appointment:
- The house is holding 60 degrees or better and the weather is mild
- One room is cold but the rest of the house is fine
- The system runs but cycles more than it used to
- Heat works, but something sounds different
Waiting for daytime rates on a problem that is not urgent is a fair way to save money. We will tell you on the phone which kind you have.
No Heat Checks by Heating System
The five checks above apply to every home. If they did not bring the heat back, a few extra minutes at your specific equipment can tell us a lot before we arrive.
Gas furnace
Watch one full start attempt. You should hear the inducer fan spin up, then a click, then the whoosh of flame, then the main blower. Note where the sequence stops. If your furnace vents through a white plastic pipe on the side of the house, check that snow, leaves, or a bird nest is not blocking it, because a blocked vent shuts the furnace down on a safety switch.
Oil burner
Check the tank gauge first, and remember that gauges on older tanks stick. If the tank is low or recently ran dry, the burner may have pulled sludge into the fuel line, and it will keep locking out until the line and filter are cleaned. Press the red reset button once at most. On single-digit nights, untreated oil in an outdoor tank or exposed line can gel, and the burner starves even with a half-full tank.
Hot-water boiler
Look at the pressure and temperature gauge and write down both numbers. A typical residential boiler runs 12 to 20 psi cold, and a reading near zero usually means a leak or a feed problem. Put a hand near the circulator pump. A gentle hum and slight warmth is normal, while silence or a loud grind is worth mentioning. If one zone is cold and the rest are fine, say so, because that points at a zone valve rather than the boiler.
Steam boiler
Find the sight glass, the vertical tube on the side of the boiler. The water line should sit near the middle. If it is empty, the low-water cutoff is holding the burner off, and that safety doing its job is the most common dead steam boiler we see. If it is full to the top, the boiler is flooded, and that needs attention too. Do not add water unless you know your system, because the wrong amount causes its own problems.
Heat pump
Set the thermostat to Heat, not Emergency Heat, and give the system a few minutes. Look at the outdoor unit. A thin coat of frost that clears itself is normal defrost, and a brief cloud of steam during defrost is normal too. A unit encased in solid ice is not, and neither is an outdoor fan that never spins. If the air from the vents feels cool, remember that heat pump supply air runs cooler than furnace air and can still be heating the house.
What We Do When We Arrive
Knowing what the visit looks like takes some of the stress out of a no-heat night. The technician starts with what you found in your checks, then tests the system at the exact point where the startup fails. On oil equipment we check the fuel supply and filter first, then the nozzle and electrodes, before condemning anything bigger. On gas equipment we test the igniter and flame sensor, check the pressure switches, and run a combustion check before we leave.
You get the diagnosis in plain English and the repair price in writing before any part goes in. Most no-heat repairs are finished the same visit from truck stock. If a part has to be ordered, we tell you the timeline on the spot and make sure the house is safe in the meantime.
What a No-Heat Call Costs
Our service call is $189, and it includes the diagnosis and the first hour of labor. Parts are extra, and we price them in writing before we install anything. After-hours emergency calls are $249. Most no-heat repairs are handled within the service call plus a part. A major repair, such as a motor, control board, or circulator, runs $500 to $950 on average.
If a repair quote passes half the cost of a new system and the equipment is 15 or more years old, we usually advise putting the money toward replacement instead. That is the same 50 percent rule most of the industry uses, and we will show you both numbers so you can decide.
No Heat Right Now?
Run the five checks, then call and tell us what you found. Same-day heating repair across Suffolk and Nassau, $189 service call including the first hour of labor.
Call 631-591-2289Why No-Heat Calls Look Different on Long Island
About a third of the homes we service heat with oil, so the first question we ask is when the tank was last filled. A tank that runs dry pulls sludge into the fuel line, and the burner locks out even after an oil delivery. Steam systems are the second local wrinkle. Pre-1960s houses in Nassau and western Suffolk often run one-pipe steam, and a low-water cutoff doing its job looks exactly like a dead boiler. On the North Fork and East End, burner lockouts after a cold snap are a weekly event for us.
Power matters too. After a PSEG outage, high-efficiency furnaces and boilers do not always restart on their own, and some need a control reset before they will fire. If your condensing furnace vents through a sidewall pipe, a frozen condensate line after a single-digit night will shut it down until the line is thawed. None of this shows up in a national troubleshooting checklist, and all of it changes what we put on the truck before we drive to you.
If you smell gas, suspect carbon monoxide, or see smoke, get everyone out first. Call 911 and National Grid from outside. Call us after the utility has made the house safe.