Reasons the Furnace isn’t Working
Most households rely on their furnaces to provide a comfortable environment against the outside winter air, so these systems must work properly.
Most households rely on their furnaces to provide a comfortable environment against the outside winter air, so these systems must work properly. If the thermostat is turned on, but the inside air does not match the set temperature, no matter how long the furnace runs, it may be time to call a professional. Consider the following reasons why a furnace may not be working to find the source of heating issues.
Change the filter
If the furnace is running but shutting off before the house warms up to the set temperature, the filter may be dirty. The filter is the barrier that keeps dirty air, allergens, dust, and pollen particles from entering the home, so it must be cleaned or changed regularly. Once it becomes clogged with all the debris it’s protecting the home from, the air cannot flow as well through it, and that may make the furnace dirtier and not function properly. Keep the filter clean or change it regularly to prevent furnace issues.
Check the fuse box, circuit breaker, and switches
If there is no sound when turning on the furnace like the system trying to start or the fan motor running, start by checking the fuse or circuit breaker. Sometimes, it’s as easy as a simple reset. If that’s not the problem, check to see if someone accidentally turned off the furnace at the furnace switch, which is usually found on the side of the unit. Always check that there is power running to the fuse or circuit breaker; do not call a technician only to realize the system has been turned off all along.
Inspect the thermostat
When inspecting the thermostat, ensure that it’s set to the heat setting and that the temperature is high enough. Turning the system a few degrees higher may help to start it. If it’s a programmable thermostat, check to make sure it’s set for the correct times. And remember, many thermostats use batteries. If it’s been a long time since the batteries were changed, they may need to be replaced. It’s a good maintenance plan to replace thermostat batteries every few months, especially at the beginning of the heating season. It’s simple, inexpensive, and can avoid an inconvenient shutdown. If these simple solutions do not resolve the problem, there could be issues with the wiring, in which case professional help is best.
Check the gas and pilot lights
If the gas valve has ever been turned off, make sure it’s turned back on before using the furnace again, or fuel cannot be produced through the gas furnace. Older furnaces may have a pilot light that also needs to be lit, so check for this light if the furnace is more than 20 years old. If there appear to be issues with either, contact an expert who can resolve the issue promptly.
Clear grilles and vents
If the air goes on, but no heat enters certain rooms of the house, an air register, grille, or vent may be blocked in the room. Check to make sure registers are open and that furniture isn’t blocking the vents. Anything put in front of a register can block airflow, which may cause the furnace to overheat, work harder than it needs to, or not have enough power to blow enough warm air through the house.
Check for blocked ducts
If the grilles and registers have been checked, but there’s still not enough heat in some rooms of the home, it may mean there are blocked ducts or even a leaky duct that’s letting the warm air escape before it reaches the room. Clear the ducts and make sure they are clean and sealed. Any obstructions like built-up dirt, dust, or even rodents can prevent the heat from reaching the rooms properly. If there are any doubts or hesitations about maintaining the ducts independently, always call an expert who has the knowledge and experience to do the job correctly.
Check intake and exhaust vents
Another airflow issue comes from the outside exhaust and intake being blocked. Sometimes, leaves, debris, or even birds can enter the exhaust flue. This can sometimes be cleared independently, but if there’s any doubt, it’s always best to contact a professional to ensure the job is done safely and accurately.
Look for corrosion and dirt in the furnace
The furnace may need to be turned off and the front panels of the furnace removed to check for things that don’t belong, such as rusty components, corrosion, spider webs, insect remnants, lint, or dust. Compressed air or a vacuum may help to clean things up, but hire a professional to change any components that are corrupted.
Clear drain lines
Both high-efficiency furnaces and boilers have drain lines to carry away the flue gas condensate. If the drain line is clogged with dirt, sediment, or mold, the furnace or boiler may stop working. Flush the drain lines if this is the issue.
Reset the furnace
Most modern furnaces with electronic ignition have a lockout mode if the ignition sequence fails. Given time, they usually reset on their own, but rather than wait, try turning off the furnace, wait a minute, then turn it back on. Lockouts can be caused by electrical brownouts or blackouts or by low gas pressure. If any of these conditions are present, a reset may be all that’s needed. Otherwise, if lockouts continue to occur, professional help is necessary.
A furnace not working properly could be due to many reasons. There’s a long list of problems to sort through that could be overwhelming to many homeowners. Once the basics have been checked, such as the power source and blocked vents, it may be best to call a professional. Hiring an HVAC technician with the right experience and knowledge brings peace of mind that the job is done right the first time and that the furnace is quickly returned to working order.
When you need heating or refrigeration service, maintenance, or repair, call us at Affordable Comfort A/C and Heating at 602-574-1205.
