How Often to Service a Furnace in NH

Updated 2026-09-30

Service a furnace in New Hampshire before you need it, which in this climate means a planned visit in early fall, and change the filter through the winter on the interval the manufacturer and the dirt in your house actually require. There is no state law that sets the month. There is a long heating season, from October to April in a normal year and longer in the north, and a furnace that was last opened the day it was installed is a January emergency waiting for a night you did not choose. Call (603) 420-0791 to be connected with an independent contractor who will quote the tune-up. Confirm the license that matches the fuel, and confirm insurance. This site does not perform the service.

What the fall visit should cover

Match the visit to the fuel. A gas furnace needs the burners and flame sensor cleaned, the filter checked, the blower looked at, the condensate system checked on a high-efficiency model, the vent confirmed, and a combustion check if the contractor is equipped to do one. A propane furnace is the same family with a different supply. An oil furnace needs the burner serviced: nozzle, electrodes, cad cell, strained fuel, flue passages, and safety controls. Saying "they serviced it" without those steps is a filter change with a clipboard.

Ask them to look at the heat exchanger for obvious failure and to say so if they see rust, water, or flame rollout. A tune-up that hides a cracked exchanger is not maintenance. It is a reason to stop and quote a repair or a replacement. The decision framework is in when to repair or replace.

Filters are not annual

A one-inch filter in a house with pets or a renovation can be done in a month. A thick media filter lasts longer and can choke a blower if it is the wrong resistance. Write the size on the blower door so you are not guessing in the dark. If you cannot remember the last filter, the fall visit is already late. Filters are something you can do between visits. Combustion work is not.

Signs you should not wait for fall

No heat, a burner that will not stay lit, a yellow flame on a gas burner, a smell of fuel, soot, water under a condensing furnace, a blower that runs without heat, or a furnace that starts and stops every few minutes. Those are repair symptoms. The maintenance page is the wrong product until the failure is found. Furnace repair is the matching service. If you smell gas, leave and call the utility emergency line before you call anyone else.

A hot-dust smell for a short time on the first cold night is common. A smell that continues is not. Banging that starts after a long idle period can be ducts expanding, or it can be a delayed ignition. Describe it. Do not decide it is harmless because a neighbor said so.

Heat pumps and boilers are not this calendar

A furnace schedule does not cover a heat pump that runs all year. Those want a heating look and a cooling look. A boiler wants its own checklist: circulators, zone valves, relief valve, expansion tank, and the burner for the fuel you have. If your house has a boiler, use furnace versus boiler so you book the right visit. The maintenance page is the service we connect.

What changes the quote

One appliance or several, gas or oil, whether combustion testing is included, and how far the contractor is driving. We do not print a statewide tune-up price. Ask what is included and what a discovered repair will cost before they do it. You can decline the repair and still pay for the visit. The contractor is independent. People in photos are actors or models. This site does not warrant the condition of the furnace after the visit. You still own the decision to run it.

Records that make the next visit faster

Tape a card to the furnace door: filter size, last service date, last repair, and the fuel company if you use oil or propane. A technician who can read that card spends the visit on the burner instead of on archaeology. If you move into a house and the card is blank, the first fall is when you learn the system's history, not the third no-heat night.

If a property is a rental, decide in advance who changes filters and who may call for service. A tenant who is not allowed to change a filter will not, and the furnace will run hot all winter. Put the rule in writing with the person who lives there. The referral line can connect a contractor. It cannot manage a lease. The invoice should name the property address you confirm on the phone, because this website does not keep a list of customer addresses and will not invent one.

Do not skip a year because the furnace 'seemed fine.' Fine is the sound it makes when it starts. It is not a look at the heat exchanger or the flue. The visit is how you find out it is fine. If money is tight, ask the contractor what the minimum safe scope is and what you will skip. A filter you change yourself plus a combustion check may matter more than a cosmetic cleaning. Get that priority from the person who will sign the work, not from a national blog. Then book it before the first hard freeze, when the schedule still has room. Call (603) 420-0791 with the ZIP code and the fuel type.

If you have skipped several years, say how long it has been. Do not expect the first visit to be only a filter. The contractor may find soot, a brittle heat exchanger, or a drain blocked since the furnace was installed. That is still worth doing before a cold week, not during one. Book the visit, keep the notes, and put the next fall date on a calendar you look at. Call (603) 420-0791 with the ZIP code and the fuel. Confirm the license that matches that fuel.

How often to service a furnace in New Hampshire