Save Time (And Money): The Top 5 Most Common HVAC Issues and What You Should Do Before Calling For Service

By James K. Kim

You might be on a first-name basis with your trusted HVAC service technician who regularly visits your home to work on your central heating and air conditioning system.

But does that mean you want to see him or her on a regular basis (especially to service an issue that you could’ve easily fixed yourself)? Probably not.

That’s why we’ve put together this easy checklist of HVAC troubleshooting tips and tricks for homeowners who think they might need to make a service call for their home’s heating and air conditioning system.

Imagine being able to avoid a service call charge (plus save all that time spent waiting for the technician to arrive at your home) by easily remedying a very minor HVAC issue yourself.

You might be able to make that happen when you follow these DIY checks for your HVAC system before calling Cottam Heating & Air Conditioning for service.

1. What to do if your HVAC system is not running

Check to see if the thermostat is working

If your thermostat just has a blank screen, it could be due to dead batteries. Replace with fresh batteries and see if that does the trick.

If you have a new model thermostat, it may display an error message with accompanying instructions to follow if there is an issue with your system.

Keep the owner’s manual handy as a reference if you are unsure about a setting. Perhaps someone else in the household may have adjusted something without your knowledge.

Check to see if the circuit breakers are tripped

If the thermostat is on, but the HVAC system still isn’t running, there may be a tripped breaker in the electric panel fuse box.

Sometimes a power surge or outage can trip the HVAC system’s corresponding fuse, which cuts power to the system until the breaker is re-set.

If the breaker trips again quickly, it’s possible there may be a more complex electrical issue. If that’s the case, it may be best to leave it to the experts and call your trusted local electrician to investigate further.

Check the condensate drain line for blockage

Certain central AC systems have an indoor coil component that has an emergency float switch attached to an emergency drain pan (made of either metal or plastic) placed under the unit, and connected into a drain line (usually a small PVC tube running away from the unit).

The purpose of these items is to prevent potential water damage to the ceilings and floors below by shutting off the system and stopping the overflow of condensation due to a cooling system issue, such as a blocked condensate drain line. Sounds pretty handy, right?

However, when this occurs, the condensate drain line should be checked and cleared for blockage. A sure sign of an obstructed line is standing water in the emergency drain pan and around the drain line.

While a clogged drain line is not necessarily difficult to solve, it may still be a good idea to have a professional HVAC service technician check the system to see if there is a larger issue causing the blockage in the first place, and if needed, they can use their own specialized tools for clearing all blockages in the entire drain line.

Check for any unlatched panels on the furnace or air handler unit

Most models of furnaces and air handlers have a safety feature that prevents the system from operating if its main panel door is not fully closed and secured.

You can open the unit’s panel or door, and doublecheck the unit is not running.

After a minute or two, try replacing the panel or closing the door securely, and power on the unit to see if that works. If that doesn’t solve the issue, there may be a deeper issue that would require diagnosis from a professional HVAC service technician.

Check if the indoor and outdoor power switches are ON

The indoor HVAC unit will typically have a power switch located near it (usually with a red switch plate). Outdoor condensing units and heat pumps should also be located close to an electrical disconnect box as well.

If a system is not running, it is possible that these switches may have been turned off inadvertently.

If you notice either the indoor power switch or the outdoor disconnect is off, then if you feel comfortable in doing so, try turning it to ON and see if that gets your system up and running. When in doubt, be sure to call your local, trusted, and reputable heating and air conditioning company who can send a qualified and knowledgeable service technician who can safely determine if the power is the reason your HVAC system is not running.

2. What To Do If Your HVAC System Is Running All The Time

On the opposite side of the coin, you may encounter a situation where your HVAC system runs continuously. Why would this be happening? Here are a few potential reasons and steps to try.

Consider the outside temperature

If your area is experiencing an extended weather event, such as a record heat wave or sub-freezing cold snap. If this is the case, then pretty much any HVAC system will need to run continuously to try and maintain the thermostat set temperature.

To counter this, you can try adjusting the thermostat’s set temperature temporarily in order to more efficiently run your system while maintaining an acceptable indoor comfort level you can live with for the time being.

During the summertime, consider setting the thermostat to 78 degrees F, and in the wintertime, try setting the thermostat to 65 degrees F.

Another suggestion from the US Department of Energy for when you are out of the house or at night is to lower your thermostat in the winter by 7 to 10 degrees and increase the thermostat by a few degrees in the summer.

While these settings may not be your first choice for temps, remember this is only temporary and it’s in an effort to prevent your HVAC system from running overtime and running up your energy costs.

Another consideration is installing a smart thermostat. Not only will the smart thermostat “learn” your preferred settings, but it will also automatically adjust the set temps so you don’t have to continue to change them manually.

Inspect your filters for clogging

All HVAC systems rely on airflow to work properly.

That’s why a clogged or obstructed filter can make the system work harder and run longer to reach the set temperature on your thermostat. You may feel very little airflow coming from the supply vents when the system is on.

As a result, your utility bills will increase and the operational lifespan of the equipment will decrease.

Depending on the indoor air quality of your home, filters should be changed regularly, such as every 30 days if it is very dusty or there is a lot of airborne particulates from smoking or pet hair.

At the very least, filters should be changed during every seasonal maintenance visit by your HVAC service technician.

Regular filter changes and seasonal maintenance visits will keep your HVAC system running more efficiently and maximize its useful operational lifespan while maintaining a comfortable indoor climate and improved indoor air quality all year long.

Check if the return air vent is blocked

Another good idea is to double-check that the return air vent that feeds air back into a ducted HVAC system is free and clear to prevent airflow blockage. The return air vent is usually located in the wall or ceiling so it can collect (rather than distribute) air.

Sometimes things like furniture, artwork, or other types of objects can block part or all of the return air vent, forcing the HVAC system to work longer and harder.

3. What To Do If Your Heat Pump Is Blowing Cold Air

Mini split heat pump systems are an excellent technological breakthrough in the world of HVAC. However, they do come with a learning curve for those switching to them from traditional gas-fired heating or split air conditioning systems.

One of the most common complaints from homeowners is the lack of heat or even lack of airflow when the user calls for heat.

There is no need for an alarm, as the system will need a few minutes while the heat pump’s coil warms up after sitting idle.

It’s also important to note that if the heat pump is connected to multiple indoor mini-split units, then each must be in the same mode (either all in heating or all in cooling) to operate.

In other words, you can’t have one unit set to COOL and another unit set to HEAT and expect them to work. They must all be set to the same mode.

4. What To Do If There’s A Strange Smell Coming From The HVAC System

If you turn on your heat for the first time in the fall or winter, you may detect a slight burning smell. Rest assured, this should only last about a half hour or so and is actually quite normal as the heating system ignites for another cold season of operation.

However, if the burning smell lingers for longer than a half hour or more, then it’s possible there may be an issue with the heating system. If this is the case, turn off the heating system immediately and call your trusted HVAC company of choice. If you live in Westchester County, New York, and need HVAC service, contact Cottam Heating and Air Conditioning. We have emergency service technicians available 24/7 who are ready to assist you with your most pressing cooling or heating issue.

Another abnormal smell you absolutely should not ignore is if you detect a natural gas smell, especially coming from your natural gas-fired heating appliances, such as a furnace or boiler.

If you detect a natural gas odor, make sure your heater is OFF, and call your local utility provider immediately.

5. What To Do If There Are Unusual Noises Coming From the HVAC System

Due to their mechanical nature, no HVAC system operates under complete silence.

However, if you hear noises such as loud, sudden pops and banging thumps, or metal scraping, then this could be an indicator of an out-of-balance or corroded component.

If you are experiencing noises from your system, then turn it off immediately and give your trusted HVAC company a ring at your earliest convenience. The issue won’t likely improve on its own…in fact it will likely get worse.

Conclusion

While some things related to your HVAC system can be handled easily by the homeowner, there are plenty of bigger issues that should be addressed by a professional.

Perhaps the best way to limit any of these issues from developing into a major costly problem is to have regular seasonal HVAC visits from your trusted local heating and air conditioning company.

For home and business owners located in Westchester County, you can reach out to Cottam Heating and Air Conditioning to inquire about our Preferred Client Maintenance Plans to ensure your HVAC system is running efficiently and safely year-round while saving you money.