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HVAC Basics: Package Unit Air Conditioning Maintenance

By Jul 2, 2020July 10th, 2020Home DIY
HVAC Basics Package Unit AC Maintenance

Do you have a package unit HVAC?  This all-in-one system needs regular maintenance to keep it running smoothly.  We’re coming into the cooling season and the A/C side of your system might need some attention.  Today I’m going to show you how to give the air conditioning side of your package unit a check-up to keep it going strong.  

There are two main types of HVAC systems; package units and split units.  My house happens to have both; a split unit for the second floor and a package unit for the first floor.  

A split unit system has an air conditioner outside, and a furnace inside.  Our furnace is in a closet, but if you have a basement yours may be down there.  The air conditioner and furnace work together to keep your house heated and cooled.  Need to give your split unit a tune-up?  I go over it all in How to Maintain Your Air Conditioner.  

A package unit system, on the other hand, has both the air conditioner and furnace (or air handler) in one unit.  That’s why it’s called a package unit, it’s all together.  Our package unit is outside our house, right next to the air conditioner for our second floor.

HVAC Basics Package Unit Air Conditioning

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HVAC Basics: Package Unit Maintenance

  1. Inspect Package System
  2. Clean Package System
  3. Test Motor and Compressor
  4. Check Temperature Differentials
  5. Perform Ongoing Maintenance

1. Inspect Package System

Before you start inspecting your package unit make sure to turn off the power to your HVAC.

turning off power to HVAC

Check for Blockage of Condensation Line

Once the power is off, I start by visually inspecting the unit.  I’m looking for signs of wear and blockage of the overflow or condensation line.  When the AC is running, condensation is produced and it needs to be able to drip out of the system.  You don’t want the overflow line to be blocked … and you can see that mine was.  

blockage of overflow line

My overflow line was overgrown with vegetation and it was blocked with dirt as well.  I removed the dirt and then used my shop vac for good measure.  I’ll make sure that the condensation is dripping out of this line when I turn the system back on later.  

suck dirt from overflow line with shop vac

Check Electrical Connections

Next I check the electrical connections on the package unit. The unit’s power should be off before you do this.  All I’m looking for here are any wires or lines that don’t feel secure. Thankfully all of mine were fine, but if I did find a loose connection I’d call in a professional.  There are things I’m comfortable checking and fixing, but electrical wires on my HVAC system is not one of them.  If you feel uncomfortable at any point doing this check-up, don’t hesitate to call in an expert.  Trane Residential has certified technicians that can come out and take all the steps needed to make sure your system is ready to go.  

Check Duct Work

Because the package system is outside, it has to connect to the house with ductwork.  And it’s also exposed to the elements which can lead to problems.  On our system, the duct tape on a seam was loose and peeling off. 

loose duct tape on HVAC

This is an easy problem to fix.  Just pull the old duct tape off, clean the surface and apply new duct tape to the seal.   

putting new duct tape on HVAC

2. Clean Package System

Remove Debris

With the package unit still turned off, it was time to clean up the unit.  Make sure to cut back any overgrown foliage nearby, and remove twigs, leaves and anything else on or near your HVAC.  I have some vegetation that was growing close to my package unit which was easy to rip out.

removing plants near HVAC

Clean Condenser Fins

Cleaning the condenser fins on your package unit is a simple step you can take to improve its function.  It’s important to have a clean condenser, because the outside unit is designed to release heat, so having good air flow is key.  When the condenser fins are gunked up with dirt, pollen, and leaves, it cuts down on the air flow.  I cleaned the condenser coils on my split unit and the process is very similar with a package unit.  

I sprayed a foaming air conditioner cleaner on the fins of my compressor. 

spraying foaming cleaner on HVACThen I let it sit for a few minutes, and I rinsed it off gently with water.  If you choose to rinse off the cleaner, make sure the water pressure is low so you don’t damage the fins.  Using a hose is fine, mine just doesn’t reach this side of the house, so the watering can did the job.

HVAC Basics Package Unit AC Maintenance

When I was done, the condenser fins were looking good and I was ready to move on to the next step.

Vacuum Inside Package Unit

With the power still turned off I carefully removed the cover to our package unit.  I wanted to see the condition inside the unit. This part might look scary, but with the power off you’re totally safe and it’s just a few screws holding the cover in place.

There were a lot of leaves, dirt and debris inside my system so pulled most of it out by hand.  Then I carefully vacuumed this area as well.  Keeping this area clean will help the unit perform most efficiently.

removing debris from inside HVAC unit

3. Test Motor and Compressor

Test Motor for Package Unit

With the outside work done, it was time to turn the power back on.  Testing that your HVAC is working by turning it on early in the season is a smart idea. There’s nothing like hitting that first really hot day and realizing your AC isn’t working.  Once you know the motor is working and it’s turning on, it’s time to make sure the compressor is in good shape.  

Test Package Unit Compressor

An easy way to make sure your compressor is working is to turn the air conditioner by setting it to cooling mode and lowering the temperature on your thermostat.  Then go outside to the package unit.  While it’s running you should be able to feel the warm air being pushed upward by the fan and the condensation should be dripping.   These are both signs that it’s doing its job removing heat and moisture from the air.   

condensation dripping from overflow line

4. Check Temperature Differentials

So now we know it’s working, but how well is it cooling?  One of the easiest checks of performance is to look at the temperature differentials from your package unit.  The temperature differential is the difference in air temperature going in the return vent and coming out of the supply vents.  This shows you how well your system is cooling the air.  I checked our temperature differential by hold a meat thermometer up to a return vent. 

getting temperature on air at return vent

Then I got the temperature at a supply vent. 

temperature of air coming from supply vent

It was 73.4 at the return and 58.8 at the supply.  This put my temperature differential at 15.4 degrees.  From the guidance I’ve found, you want a temperature difference of between 16-22 degrees. 

The fact that my package unit is on the lower side isn’t surprising.  Our system is more than 15 years old, and a package unit’s lifespan is typically 15 – 20 years.  If your system isn’t delivering the cooling you want, you can call your Trane dealer and talk about options to repair it or get a new system.

They have packaged systems like the Trane’s XL16c their most efficient gas and electric model.  It has up to 16.60 SEER and 81% AFUE and is Energy Star qualified, which would be a huge improvement over my old unit.  A Trane specialist will come out to your house to take readings and measurements so they can make sure you get the right-sized unit for your space.  We went through this process when we Upgraded to a High Efficiency HVAC System.   

5. Perform Ongoing Maintenance

Change Air Filters

Another easy step you can take to keep your package unit performing at its best is to change the air filter.  Many package units have filters right on the system that need to be changed and are easy to forget about. Our unit doesn’t have an on-board air filter, but I went ahead and changed the air filters in our house.  

changing air filter in house

Changing the air filter is an easy step to take and it’s really important.  A dirty, clogged air filter on an HVAC system will cause it to work much harder, which can put a strain on your unit.  Trane also sells air filters which I’ve been using for awhile now, and they hold up well.  

Clean Air Supply and Return Registers

Finally, cleaning the supply and return registers is the last step to maintain your package system.  Some of my supply registers were set in the floor, and I was able to lift the grate off and vacuum the opening.  The supply register in our kitchen was pretty gross with crumbs and bits of food falling in; it needed a good cleaning.  Most of our return registers are up high on the walls and the grates are screwed into place.  In that case, I vacuumed the fins on the grate with my shop vac.  

I hope this guide helps you get ready for cooling season and take care of any maintenance or repairs you need done before you’re stuck without AC on a hot day!

If you liked this post I have more HVAC information available in my HVAC Basics Series.  

Trane Residential provided me with product and/or monetary compensation as a sponsor of this build.  All opinions are my own and are not filtered by the sponsor.