When your heating or cooling fails to turn on or otherwise malfunctions, your home can become uncomfortable quickly. Many of the most common HVAC troubles have simple causes. Let’s explore the aspects of your HVAC system that you should check before scheduling a repair technician.
Thermostat
The thermostat is the brain of any HVAC system, and the slightest malfunction can cause many odd behaviors. When your system fails to turn on, you might find that the thermostat screen has gone dark. In that case, check if your thermostat is hardwired or battery-powered. If it’s hardwired, this usually means there’s another issue causing the thermostat to shut the system down to protect it. If it runs on batteries only, they’re probably dead. New batteries may be the only fix you need.
If you’ve noticed that the system is constantly running, ensure the thermostat fan setting is “auto” and not “on.” For temperature and airflow issues, verify that the thermostat is in “cool” mode in summer and “heat” mode in winter. You can also remove the faceplate and clean any dirty contacts. Some smart thermostats have a test mode that will help you confirm proper functioning and configuration. As a last resort, you can factory reset the thermostat per the instructions in the owner’s manual.
HVAC Filter
All HVAC systems have one or more air filters to keep dust and other debris out. Air filters restrict airflow, and HVAC systems need static air pressure. A common issue is that a homeowner hasn’t checked, cleaned, or changed the air filter in a while. That causes the static air pressure to increase. Advanced systems often shut themselves down as a response to the pressure rise. In less sophisticated symptoms, you may experience a range of issues.
The restricted airflow can cause a whistling sound at the supply vent. You may notice short cycling. This is when your system turns on and off frequently. A clogged filter can also cause increased energy consumption. If you have a smart thermostat that monitors energy usage, it may alert you to a spike. This problem can also cause either the outdoor condenser coil or indoor evaporator coil to freeze over.
Swapping out the old filter may do the trick. Even if you don’t have a spare filter, you can remove the old filter to confirm this is the problem. If you have a mini-split, those filters are inside the indoor units instead. You generally wash those. You may need to replace them if they’re old or damaged.
Circuit Breaker
Perhaps you heard a loud bang or excessive vibration from the outdoor unit followed by a tripped circuit breaker. In that case, you shouldn’t troubleshoot the system. That unexpected noise was likely a hard start. It indicates a serious problem with the condenser pump. If caught early enough, our technician can save the pump. Turning the pump on again could permanently damage it.
Otherwise, if the system has turned off and won’t turn back on, rule out a power outage first. If the power is on, check the circuit breaker. This is true even with fuel-fired systems, as many use electricity too. If the circuit breaker for the HVAC system has tripped, you can reset it. If it trips again, it’s time to stop troubleshooting and call the pros. It could just be that you have an old breaker that requires replacement. It can also be an issue with electrical components, the condenser unit, or refrigerant pressure.
HVAC Disconnect Switch
Most local electrical codes in the U.S. require an HVAC disconnect switch installed outside the home. In the case of an emergency, it lets you, a technician, or a first responder deactivate the entire system.
The switch can cause power issues unrelated to the breaker. The handled plug fits tightly and securely into a socket. If the handle is loose, you can try reseating it, and the system should turn on and run as normal.
Combustion
In several scenarios, you shouldn’t troubleshoot. These include noticing a “rotten egg” or gas smell. Other notable warning signs include carbon monoxide (CO) alarms and a pilot burning a color other than blue. Turn the HVAC system off, and turn off the gas supply if you know how and are comfortable doing so. If there’s a potential risk of CO poisoning, leave the home and schedule a repair.
If the pilot light has gone out, you can relight it. Clear out the chamber first. Turn the knob to “pilot.” Push and hold in the “reset” button. Use a long match or lighter to relight the pilot. If it lights, let go of the reset button and switch the knob to “on.” If it won’t relight easily or goes out again, stop troubleshooting and contact the pros.
Outdoor Condenser Unit
The outdoor unit can cause many odd noises and airflow issues. Look inside the unit to ensure it’s not cluttered with leaves, branches, and other debris. If there is debris, you can clear it out and see if that helps.
In some cases, you should stop troubleshooting and call us immediately. These include noticing any damage to the fan that pushes air up out of the unit. If you hear a hissing sound, the refrigerant might be leaking. If the outdoor unit has frozen over, it needs our attention. In that case, set the fan mode to on but the cooling or heating off. That will help the system defrost without causing further damage while you wait for us to arrive.
Vents
If you’re experiencing airflow or temperature issues, check the vents throughout your home. All the vents in a home should be open unless your HVAC provider has configured the system otherwise. If you notice the vents are dirty, clean the faces and insides. Closed and dirty vents can cause issues like cold and warm spots in your rooms. It can also cause temperature differences between floors.
Condensate Drainage
All HVAC systems have a condensate drainage system that carries excess moisture out of the home. If you notice that the drip pan isn’t emptying, look at the mouth of the drain pipe. Sometimes, the clog is readily visible, and you can clear it away. Deeper clogs will need to be addressed by a technician. Overflowing water indicates that you likely have a failed wet switch and will need the pros.
Do You Need Help With Your HVAC System?
If you’ve tried troubleshooting your system and still have a problem, Blue Best Plumbing, Heating, Air, Generators is the company to call. We serve homeowners and businesses throughout Bountiful and the surrounding areas and have over 20 years of industry experience. Our HVAC technicians install, maintain, and repair furnaces, heat pumps, air conditioners, and ductless mini-splits. We specialize in ductwork, indoor air quality, and smart thermostats and offer a maintenance plan that saves our customers money. Our indoor air quality team installs and services air purifiers and humidity control. Our plumbers install and repair pipes, drains, tank and tankless water heaters, water filters, water softeners, toilets, and other fixtures. Contact us today with any questions or to schedule an HVAC maintenance service appointment or on-site consultation.
