Furnace Checklist Including The 10 Most Frequent Furnace Problems

September 24, 2015

Though we expect our equipment to work flawlessly, some homeowners and property owners get a nasty shock when they discover the heating system isn’t working as expected. Some issues may leave you scratching your head as you try to discover what the root problem is, and may lead to a phone call seeking outside assistance. We hope the list below will be a good re-introduction to your heating system and some of the most common issues or problems that might arise during its life and a checklist for maintenance:

1. Forgetting to Maintain Your Equipment
The best way to avoid unforeseen problems with your furnace or boiler is to regularly maintain the equipment. You should have a professional inspect and service your system at least once a year to help nip potential problems in the bud, ensure safety, and prevent inefficiency that will waste energy and can cause your heating bill to skyrocket.

2. Pilot Light and Ignition Problems
If the automatic ignition or pilot system is malfunctioning, you’re going to have a hard time heating your home. An easily corrected issue like dirt or dust accumulated by the igniter or pilot assembly, or the burners, can cause a lot of aggravation at the worst possible time–leaving you with no heat just when you need it the most. Routine annual maintenance can help you avoid a potentially costly service call centered on these issues.

3. Old and Clogged Furnace Filters
Clogged furnace filters are extremely common because filter maintenance isn’t always in the forefront of property owners’ minds. In many cases, replacing the filter just once per year is simply not frequent enough. Not only will a clogged furnace filter cause the main blower to work harder, potentially shortening the lifespan of the blower motor, but it can also cause overheating of the furnace’s heat exchanger, the heart of the system. Consistent overheating of the heat exchanger over an extended period of time can cause premature failure of the metal in the exchanger, resulting in holes or cracks that could create a potentially dangerous condition. This type of furnace repair is avoidable simply by replacing your filters on a regular basis.

In a worse case scenario, you could be putting your family in harm’s way due to carbon monoxide leakage, and also be looking at a costly repair or replacement job. In some cases, a failed heat exchanger requires replacement of the entire furnace! Please make note that some furnace filters that are marketed as high efficiency anti-allergen filters have a more tightly woven material which, in some systems, can restrict the airflow more than is recommended. Of course, if left unattended for long periods, this type of filter could create a variety of negative consequences for your forced air heating system.

There are no rules for thumb for filter replacement, and the wide variety of products out there make it even harder to provide general guidelines. Bring in a service pro for thorough, professional, annual maintenance and once they’ve learned more about your system, ask their advice.

4. A Noisy Furnace or Boiler
If your central forced air furnace or hot water boiler makes a lot of unusual banging or squeaking noises, they could likely indicate problems with heat delivery around your home or mechanical issues with the equipment. The worst thing you can do is fail to address the problem promptly and forego seeking the help of a professional. If you wait too long, the problem will only snowball. If you’re not sure, picked up the phone and get some free, friendly advice from a reputable heating contractor to help you decide how to proceed.

5. Your Thermostat is Broken
A failed thermostat can fail to send the correct signals to your furnace or boiler, which could cause a variety of heating problems. In most cases, a bad thermostat should just be replaced. On occasion,, when all signs seem to point to the thermostat, you may end up finding that old, frayed or broken low voltage wiring from the thermostat to your heater ends up being the culprit.

6. An Aging Heater
As time marches on, wear and tear is completely normal. Your furnace or boiler might simply be approaching the age when a variety of components begin failing on a regular basis, and repeated service calls begin ‘nickel-and-diming you to death.’ It’s often difficult to predict when an older piece of equipment will need to be replaced, but a short history of repeated parts failures certainly points to taking the time to learn more about options for upgrading your system–before authorizing the next expensive repair.

7. Your Furnace or Boiler Isn’t Heating!
This general symptom could be related to a wide variety of sources such as ignition or pilot problems, blower or pump issues, thermostat problems, lack of power or gas, or any number of internal parts failures. If you quickly hit the wall as a homeowner repairman, the best thing you can do is accurately catalog the symptoms so that when your service company comes out to fully diagnose the problem they have a head start on determining the cause.

8. Your Heater Is Working But It Can’t Keep The House Warm Enough
Insufficient heat could be related to things like filter, airflow or pumping issues, gas supply or gas valve problems, poor thermostat calibration or partial failure, intermittent limit or fan switch or flame sensor failure, or maybe other issues. There is simply no rule of thumb. During periods of extreme cold weather, it’s even possible that your furnace or boiler may not be sized to adequately handle the coldest temperatures. But don’t expect sizing to be the issue if you’ve seen those range of temperatures in prior years with no problems. Again, accurately cataloging all symptoms may help a skilled technician quickly hone in on the cause, hopefully saving you money along the way.

9. Cycling Problems
If your furnace or boiler cycles between the on and off states too frequently, unlike what you’ve grown accustomed to, you may yet again have a dirty filter or a malfunctioning thermostat, or possibly be experiencing equipment issues that won’t allow the flame in your heater to burn steadily. The reality with today’s modern equipment is that a number of common symptoms could be connected to a variety of different causes, and often only a skilled service tech, with the proper training and tools, will be able to root out the cause. Again, this points to the importance of regular annual maintenance, and learning as much as you can about your home comfort systems.

10. Your Furnace Fan or Your Boiler Pump Won’t Shut Off
Fan and limit switches, snap discs, fan centers, aquastat relays, pump relays and printed circuit control boards are some of the more common components that turn furnace blowers and boiler pumps on and off. It’s unlikely that a typical homeowner will be able to solve a problem related to their function on their own because this symptom could relate to any number of different issues–and so many different looking parts can serve the same function! Once again, this points to the need for a responsible homeowner to have a trusted HVAC contractor that they can turn to when the problem is more complicated than, say, a clogged furnace filter.

While daytime temperatures are still high in much of the Front Range, cooler nights and days are likely not far off. If you are interested in having your heating system checked before you need it, request a maintenance call today! Yes, you may still be running your AC, but If there are any problems with your heating system, now is the best time to deal with them!

Maintain your equipment to prevent future problems and unwanted costs. Keep your cooling and heating system at peak performance by having a contractor do annual pre-season check-ups. Contractors get busy once summer and winter come, so it’s best to check the cooling system in the spring and the heating system in the fall. To remember, you might plan the check-ups around the time changes in the spring and fall.

A typical maintenance check-up should include the following:

  • Check thermostat settings to ensure the cooling and heating system keeps you comfortable when you are home and saves energy while you are away.
  • Tighten all electrical connections and measure voltage and current on motors. Faulty electrical connections can cause unsafe operation of your system and reduce the life of major components.
  • Lubricate all moving parts. Parts that lack lubrication cause friction in motors and increases the amount of electricity you use.
  • Check and inspect the condensate drain in your central air conditioner, furnace and/or heat pump (when in cooling mode). A plugged drain can cause water damage in the house and affect indoor humidity levels.
  • Check controls of the system to ensure proper and safe operation. Check the starting cycle of the equipment to assure the system starts, operates, and shuts off properly.
  • Check all gas (or oil) connections, gas pressure, burner combustion and heat exchanger. Improperly operating gas (or oil) connections are a fire hazard and can contribute to health problems. A dirty burner or cracked heat exchanger causes improper burner operation. Either can cause the equipment to operate less safely and efficiently.

Actions To Do Yourself

Inspect, clean, or change air filters once a month in your central air conditioner, furnace, and/or heat pump. Your contractor can show you how to do this. A dirty filter can increase energy costs and damage your equipment, leading to early failure.