How Often Should You Service Your Furnace?

If your HVAC system is getting old, breaking down more often, or no longer keeping your home comfortable, you may be wondering: How much should I expect to spend if my HVAC system needs to be replaced?

One replacement may involve removing the old equipment and installing a compatible new system using existing ductwork and connections. Another may require ductwork modifications, electrical changes, drainage work, new controls, difficult-access installation, or other adjustments.

By the end of this guide, you’ll understand what a new HVAC system can cost, what drives that price, and how to compare replacement options based on the work your home actually needs.

In this guide, you’ll learn why timely furnace tune-ups are important, when you should service different types of furnaces, and what all a professional furnace service includes.

Why Annual Furnace Service Matters?

A gas furnace produces carbon monoxide(CO) when it burns fuel. Normally, the furnace vents this gas outside. But a cracked heat exchanger, blocked vent, or combustion problem can let carbon monoxide(CO) enter your home instead.

Since carbon monoxide(CO) is odorless and invisible, people will not realize they are breathing it. High levels can cause severe illness, loss of consciousness, and death.

The U.S. Centers for Disease Control and Prevention (CDC) reports that more than 400 people in the U.S. die each year from unintentional carbon monoxide (CO) poisoning, while more than 100,000 visit emergency departments, and over 14,000 are hospitalized.

That is why annual furnace service is important. During a service, a technician will:

• Detect safety problems before winter.
• Identify combustion, venting, and carbon monoxide risks.
• Check if the airflow and ignition components are operating properly.
• Reduce the chance of inconvenient breakdowns.
• Support efficient furnace operation.
  

How Often Should A Furnace Be Serviced

If you are wondering how often should a furnace be serviced, the best time for furnace servicing is September or October, when the temperature drops.

• For the technician: It gives them time to check that the furnace starts and shuts off properly, inspect combustion and venting, test ignition, blower, and electrical components, and replace a dirty filter.
• For the homeowner: It gives you time to address worn components or safety concerns before you need the furnace every day and helps you avoid longer appointment waits during the first cold spell.
  

Is it too late if winter has already started?

No. If your furnace is working normally but you missed annual service, you can schedule the next available appointment. A mid-season inspection is still better than skipping maintenance.

When should you service your AC?

For servicing your AC, schedule it in March or April. Doing this before the busy season gives you time to find and fix problems before you need the AC every day.

Both furnaces and AC have opposite schedules, so it’s better to plan their maintenance around the time you need them the most.

In case your AC suddenly stops working during the summer, you may need an emergency AC service. This is especially applicable in higher temperatures, or if the system is leaking, making unusual noises, or will not turn on.

For unexpected AC problems or urgent breakdowns, D.R. Mechanical provides 24/7 emergency service to help homeowners get their cooling system properly serviced.

Warning Signs Your Furnace Needs Service Before the Yearly Visit

There’s no hard and fast rule that you will have to wait for the next scheduled visit if your furnace starts behaving differently. 



These signs can mean the system needs to be checked by the technician much sooner:

• Some rooms stay cold: Uneven heating can point to airflow or furnace problems.
• Strange noises: Unusual or loud noises from the furnace aren’t something you are supposed to ignore. 
• Short cycling: If the furnace turns on and off repeatedly, have it inspected as soon as possible.
• Higher heating bills: A sudden increase without a change in usage may indicate a performance problem that needs to be monitored.
• Unusual smells: Burning or other persistent odors coming from the vents need attention.
• Yellow or flickering flame: An abnormal burner flame can indicate a combustion problem.
• More dust than usual: Excess dust can sometimes point to airflow or filter issues. Take it as a warning sign and get it serviced without any further delay.

Furnace safety next step: If your CO alarm starts sounding, leave the home immediately, move to fresh air, and call 911 or your local emergency service from outside. Do not re-enter until you are told it is safe.

How Often to Tune Up a Furnace: Gas, Oil and Older Units

The answer to how often to get a furnace serviced is usually at least once a year, but the details can vary by furnace type and age.  Gas, oil, electric, and propane systems have different components and maintenance needs, so their service schedule can also vary accordingly.

Gas Furnace Service: Annually 

You can service your gas furnace on an annual basis, preferably before the heating season. A technician can check the burners, ignition, heat exchanger, gas connections, venting, airflow, electrical components, and safety controls.

Oil Furnace Service: Once a Year, Twice in Some Cases

Oil furnaces generally need cleaning, tuning, and inspection each year, preferably before heating season. Unlike gas furnaces, oil systems can accumulate soot and carbon around the burner, while fuel and air filters also need attention.

A second inspection can be beneficial for people who have their homes in very cold areas, or for those who use the furnace heavily through a long heating season.

Electric Furnace Service: Usually Once a Year

Electric furnaces don’t burn fuel, so they do not have combustion or venting concerns like gas and oil systems. However, the blower motor, electrical connections, controls, and other components still call for proper inspection.

Servicing it once a year is usually enough unless your furnace manufacturer says it needs to be serviced more often. 

Propane Furnace Service: Once a Year

Servicing your propane furnace once annually should be enough, ideally before regular winter use. The technician can inspect the burners, ignition, heat exchanger, venting, airflow, fuel connections, and safety controls.

Furnaces Over 15 Years Old: Keep Servicing or Replace?

Annual service is still important even if your furnace is over 15 years old because its parts can become worn or damaged over time. 

At each visit, ask your technician about the furnace's condition, furnace repair history, safety, and expected remaining service life. This information will help you decide whether to keep maintaining the furnace or start planning for a replacement. 

ENERGY STAR identifies furnaces over 15 years old as a point when homeowners may want to consider replacement, particularly if repairs are becoming frequent or the system is no longer performing well.

What Furnace Servicing Includes During a Tune-Up Visit

During furnace servicing, a technician checks the system’s major operating and safety components to make sure everything is working as it should. A typical visit takes about 1 to 2 hours, depending on the furnace and what the technician finds.

Simple Checklist

A typical furnace service may include:

1. Inspect the furnace and filter.
2. Check airflow and temperature rise.
3. Inspect the blower and motor.
4. Test ignition, flame sensing, and safety controls.
5. Inspect burners and fuel connections.
6. Check the heat exchanger.
7. Inspect venting and flue connections.
8. Test combustion and CO levels on fuel-burning systems.
9. Check electrical components and thermostat operation.
10. Inspect condensate drainage on high-efficiency furnaces.
11. Clean or adjust components when needed.
12. Explain findings and recommend any necessary repairs separately.

The exact checklist can vary by furnace type and manufacturer.

What You Can Do Yourself Between Visits

Between professional service visits, homeowners can handle some of the few simple maintenance tasks mentioned below:

• Check the furnace filter regularly and replace it when needed.
• Keep the area around the furnace clean; remove boxes, furniture, and other items.
• Make sure supply and return vents are not blocked so air can move properly.
• Test your smoke and CO alarms monthly to make sure they are working.
• Leave the internal components of a gas or oil furnace to a qualified HVAC professional.

If you notice anything unusual, you can schedule an inspection instead of trying to repair the furnace yourself.

How Often to Change a Furnace Filter Between Tune-Ups

Check the filter at least once a month, especially during the heating season, and replace it when it's dirty. As a general rule, consider replacing it at least every three months, unless the filter or furnace manufacturer recommends a different schedule.



Signs That the Filter Needs Changing

Take the filter out and hold it up to a light. Replace it if:

• It looks gray or covered with dust.
• You cannot see light through a disposable filter.
• Dust is collecting around the filter slot.
• Airflow from the vents feels weaker.
• The furnace is running longer than usual.
• The filter is bent, wet, damaged, or clogged.
• It has reached the manufacturer's recommended replacement date.

Pets, allergies, high dust levels, or home renovations can make the filter dirty faster, so set a phone reminder to help you remember.

Furnace Servicing for South Jersey Shore Homes and Rentals

Homes along the South Jersey Shore can have a few extra furnace-maintenance considerations, especially when the property is used seasonally or rented to others.

• Second homes and rentals: If the property usually remains empty for half of the year, do not wait until a tenant or guest arrives to turn on the heat. Have the furnace checked in September or October, before winter arrives. This gives you time to address problems before the home needs regular heating.
• Coastal conditions: Salt air can cause corrosion of metal components and equipment. A technician can look for signs of corrosion or deterioration during routine furnace servicing, particularly in homes closer to the shore. 
• Landlords: Keep a dated record of furnace service, including the inspection date and any repairs or recommendations. These records can help you track the system's condition, demonstrate routine maintenance, and keep useful documentation for warranty purposes.

A furnace problem is much easier to address when the house is empty than when a tenant discovers it on the coldest night of the year. 

For homeowners across the South Jersey Shore, D.R. Mechanical takes the time to inspect the furnace, identify the source of a problem, and clearly explain what needs to be repaired.

Book Your Furnace Service Before the Cold Weather Arrives

For most homeowners, servicing your furnace once a year in September or October is a good idea. It gives you time to find and fix problems before you start using the furnace regularly.

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f you are noticing unusual noises, uneven heating, frequent cycling, or other changes, mention them when you book so the technician can check them during the visit.

If your furnace has not been serviced in the past year, schedule your furnace inspection now.

Frequently Asked Questions

Q1. How often to tune up the furnace?

Most furnaces should be tuned up once a year, ideally in September or October, before you start using the heat regularly. 

Q2. How long does a furnace service visit take?

A typical furnace service takes about 1 to 2 hours, depending on the furnace and whether the technician finds any problems.

Q3. Is it too late to service my furnace in winter?

No. A mid-winter service is still useful if you missed your fall appointment. If you notice warning signs, schedule an inspection as soon as possible.

Q4. Do heat pumps need servicing as often as furnaces?

Yes. Heat pumps should be professionally serviced at least once a year, although some systems may benefit from service twice a year.