Furnace Repair in New Hampshire, New Jersey & Southern Maine

What a furnace repair call actually covers

A furnace is a sequence, not a box. Your thermostat calls, the inducer motor spins up and proves draft through a pressure switch, the ignitor glows, the gas valve opens, a flame sensor confirms real fire, and only then does the blower move air. Repair is finding which link broke, and why. Everything upstream keeps working normally, which is why a furnace looks healthy right up to the moment it locks out.

We service all three fuels used across this footprint: natural gas where a main runs down the street, propane where it does not, and oil, which is close to a separate craft. Oil burners use nozzles, electrodes, cad cells and primary controls in place of ignitors and flame rods. Radiators or baseboard instead of supply vents means you have a boiler, which is a different repair.

Signs it is time to call

Some failures announce themselves. Others hide for weeks as a thermostat problem or one cold room.

• Burners light, then shut off five to ten seconds later, again and again
• The blower runs but the air coming out is cool
• A boom or whoomp at startup, which is gas pooling before it lights
• Grinding, screeching or rattling when the furnace kicks on
• Yellow, lazy or flickering flames instead of steady blue ones
• Soot or scorch marks around the burner compartment
• A carbon monoxide alarm that has sounded even once

The short-cycling symptom is worth understanding. A flame sensor is a thin rod that reads fire as a current measured in millionths of an amp. Let oxide build on it and the board sees no flame, shuts the gas, and retries until it locks out. It is the most common no-heat call we take, and it is often a cleaning rather than a part.

Carbon monoxide is where we stop negotiating

The heat exchanger is the steel wall between the fire and the air your family breathes. When it cracks or corrodes through, blower pressure can push combustion gas into the supply ducts. Carbon monoxide has no smell, so the warnings are indirect: flames that flutter or roll out when the blower starts, fresh soot, and headaches or drowsiness that ease when everyone leaves the house.

Every heating diagnostic we run includes a combustion check: carbon monoxide measured in the flue and in the room, draft verified, exchanger inspected. If it is compromised we shut the furnace down, tag it, and show you what we found. That call is never an upsell. Check your CO alarms too: the sensors expire in roughly seven to ten years, whether or not the unit still chirps.

How we find the real fault

The control board flashes a code that tells you where the sequence stopped, never why. A pressure switch fault is usually a plugged condensate trap or a sidewall vent buried in drifted snow. A tripped limit switch is nearly always airflow: a loaded filter, closed registers, a crushed flex duct, or a return undersized the day it went in. Replace the switch alone and you buy a few weeks.

So the visit measures rather than guesses:

• The full sequence of operation, from thermostat call to blower shutdown
• Manifold gas pressure on a manometer, and temperature rise against the nameplate range
• Static pressure across the air handler, which shows whether the ductwork is choking the furnace
• Flame signal in microamps, which catches a sensor going weak before it strands you

You get a price before any work starts. Trucks carry the parts that fail most, so most repairs finish on the first visit.

What the cold and your fuel change about the job

Cold snaps do not break furnaces at random. On a 40 degree day a furnace may run ten minutes an hour. Below zero it runs nearly nonstop, and the weak ignitor that survived October fails in one night. Every house in the region hits that wall the same evening, which is why no-heat calls come in waves.

Fuel changes the failure list. High efficiency gas and propane furnaces drain acidic condensate, and that line freezes in an unheated crawl space or where a sidewall vent ices over from roof runoff. Propane pressure sags when a tank runs low in a long cold stretch and the furnace takes blame for a delivery problem. Oil tanks collect water and sludge that plug the filter and lock out the primary control, and that reset button should be pressed once, never repeatedly: each press pushes more oil into a cold chamber. Closer to the coast, a furnace that has taken flood water needs its gas valve and controls replaced, not dried out.

Why homeowners call High Ground

You reach a person, not a voicemail box, and no-heat calls get same-day service wherever the schedule allows. The technician who shows up is licensed, background checked, and works for one company across New Hampshire, New Jersey and southern Maine.

Every repair carries our Lifetime Workmanship Guarantee. If the work does not hold, we come back and make it right, fast. When a repair costs close to what a replacement would, we show you both numbers instead of selling a fifth patch on a twenty year old system. We are veteran owned, we pull the permits the work requires, and we would rather lose the sale than leave a furnace running that should not be.

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