By Jake Lawson
One of the most important pieces of advice I give homeowners about HVAC equipment is simple:
Don't wait for the weather to change before thinking about your heat pump.
Every year, I get calls on the first hot day of summer or the first cold night of winter from homeowners whose systems suddenly aren't performing the way they expected.
In many cases, there isn't a major mechanical failure. The equipment simply wasn't prepared for the demands of the new season.
That's one of the major advantages of a through-the-wall heat pump: one system can provide both heating and cooling year-round. It's a practical comfort solution for homes, apartments, vacation properties, room additions, and other spaces where a dedicated heating and cooling system may not be practical.
But because a heat pump can operate throughout the year, it may accumulate significantly more operating hours than a cooling-only unit.
That's why seasonal preparation matters.
A little preventive attention before each heating and cooling season can help:
- 🔧 Identify developing problems before they become major repairs
- 🌬️ Maintain proper airflow
- 🧹 Keep filters and accessible components clean
- 💧 Protect proper condensate drainage
- ⚡ Identify obvious electrical or control issues
- 🌡️ Make sure the system is ready for the demands of the coming season
You don't need to become an HVAC technician to take good care of your system.
The goal is simply to catch small problems early and give your heat pump the best possible conditions to deliver reliable comfort throughout the year.
A few minutes of preparation before extreme weather arrives can be much easier—and far less expensive—than discovering a problem when you need heating or cooling the most.
The good news is that preparing your heat pump for the changing seasons doesn't have to be complicated. Homeowners can handle several basic inspections and maintenance tasks themselves, while electrical work, refrigerant service, and internal repairs should be left to qualified HVAC professionals.
I've learned that spending 30 minutes checking your system before extreme temperatures arrive is far better than discovering a problem during the first major heat wave or cold snap—when HVAC contractors may already be overwhelmed with emergency service calls.
In this guide, I'll walk you through the seasonal maintenance steps I recommend before winter and before summer, explain why each one matters, and help you understand which tasks are safe for homeowners and which should be handled by a trained technician.
🌤️ Why Seasonal Preparation Matters
I often hear homeowners say:
“If my heat pump worked fine last season, why wouldn't it work fine this season?”
It certainly might. But HVAC equipment operates under changing conditions throughout the year, and small problems can develop while the system is sitting idle or operating under different demands.
Over time:
- 🧹 Dust accumulates on filters and components
- 🍂 Leaves and outdoor debris collect around the unit
- 🌬️ Airflow can gradually become restricted
- 💧 Condensate drains can become dirty or blocked
- 🧱 Seals and insulation can deteriorate
- 🌧️ Moisture can affect exposed areas
- 🔩 Normal wear can affect mechanical components
The system may continue operating despite these issues, but its efficiency and performance can gradually decline.
Seasonal preparation is about finding those small problems before they become big ones.
A simple inspection before the heating or cooling season gives you time to clean, maintain, or schedule professional service when necessary—rather than discovering a problem when your heat pump is working hardest.
The best time to prepare your HVAC system for extreme weather is before the extreme weather arrives.
By preparing your heat pump before the seasons change, you can identify small problems before they develop into larger and more expensive issues.
Something as simple as a heavily loaded air filter or an obstructed outdoor grille can restrict airflow, causing the system to operate longer than necessary. That can increase energy consumption and place additional stress on components designed to provide years of service.
Seasonal inspections can also help prevent unpleasant surprises.
There's never a convenient time to discover that your heat pump isn't heating properly during the first cold snap of winter—or isn't cooling effectively when a summer heat wave arrives.
Checking the equipment ahead of time gives you an opportunity to identify potential problems and arrange professional maintenance before HVAC contractors are dealing with a surge of emergency service calls.
The U.S. Department of Energy's Energy Saver resources recommend regular maintenance of heating and cooling equipment to help maintain efficient operation, support reliability, and potentially extend equipment service life.
A little preparation before the season begins is far easier than troubleshooting a preventable problem when you need your heat pump the most.
Learn more:
🌎 U.S. Department of Energy – Energy Saver, https://www.energy.gov/energysaver
📅 The Best Time to Prepare Your Heat Pump
People often ask me exactly when seasonal maintenance should be performed.
My answer is simple. Don't wait until you actually need the equipment.
Summer preparation should preferably be done in spring, when the temperature is still mild outside. Similarly, winterising should be done in the autumn before cold weather arrives. These shoulder seasons are perfect because the system can be checked out without the pressure that comes when heating or cooling becomes a necessity.
Scheduling professional maintenance in the spring and autumn also makes it easier to book appointments. HVAC companies usually get the most business during the hottest and coldest weeks of the year, when emergency breakdowns are more frequent. Planning ahead can often mean shorter wait times and a more relaxed inspection process.
📊 Ideal Seasonal Maintenance Schedule
| Season | Recommended Tasks |
|---|---|
| 🌸 Spring | Prepare for cooling season |
| ☀ Summer | Monitor airflow and filters |
| 🍂 Autumn | Prepare for heating season |
| ❄ Winter | Monitor defrost operation and airflow |
Routine attention throughout the year keeps the system operating closer to the way its engineers intended.
🧹 Start Every Season With a Thorough Visual Inspection
I don't begin every seasonal service visit by immediately taking the equipment apart. I start by looking at the entire installation.
Homeowners can do much the same thing.
Before turning the system on for a new season, take a few minutes to inspect both the indoor and outdoor portions of your through-the-wall heat pump. Look for anything that has changed since the previous season.
Check for things such as:
- 🌿 Landscaping that has grown around the outdoor grille
- 🍂 Leaves, dirt, or cobwebs restricting airflow
- 💧 Water stains or signs of previous leakage
- 🔩 Loose or damaged trim
- 🧱 Gaps around the wall sleeve
- 🧊 Damaged or deteriorated insulation
- 🐦 Bird nests or other obstructions
- 💧 Signs of a blocked condensate drain
You don't need specialized tools to spot many of these issues.
I've found loose outdoor grilles, bird nests, damaged weather seals, blocked condensate drains, and deteriorated insulation during simple visual inspections.
The purpose isn't to diagnose complicated mechanical problems yourself.
It's simply to identify anything obvious that could interfere with safe and efficient operation during the coming season.
If something looks damaged, unusual, or beyond a basic cleaning, that's when it's best to call a qualified HVAC professional.
🌬️ Clean Airflow Is the Foundation of Performance
If you've read several of my articles, you've probably noticed that I mention airflow again and again.
There's a good reason.
Almost every major function of a heat pump depends on moving the right amount of air through the system. Restricted airflow can affect heating and cooling performance, efficiency, humidity control, operating time, and equipment stress.
Before worrying about complicated problems, make sure your heat pump can breathe properly.
During the cooling season, unrestricted airflow allows the evaporator coil to remove heat and moisture effectively. In winter, proper airflow helps the heat pump extract available heat from the outdoor air and transfer it indoors.
When airflow becomes restricted, the system has to work harder—and often run longer—to maintain the desired indoor temperature.
That's why airflow should be one of the first things you check at the start of every season.
I recommend beginning with two simple areas:
- 🧹 Indoor air filter: A dirty or heavily loaded filter can restrict airflow through the system.
- 🌿 Outdoor grille: Leaves, grass clippings, snow, ice, vegetation, and other debris can interfere with airflow around the outdoor coil.
I've been to homes where replacing a severely clogged filter noticeably improved heating performance without replacing a single mechanical component.
The equipment hadn't suddenly become more powerful.
It was simply able to move air the way it was designed to.
ENERGY STAR® also emphasizes regular filter maintenance as an important and relatively simple way to support efficient HVAC operation.
A clean filter costs very little, takes only a few minutes to check, and can make a surprisingly significant difference in how your heat pump performs.
Learn more:
🌎 ENERGY STAR Heating & Cooling, https://www.energystar.gov/products/heating_cooling
🌬 Seasonal Airflow Checklist
Before each season, inspect:
- ✅ Indoor air filter
- ✅ Outdoor grille
- ✅ Leaves and debris
- ✅ Shrubs and landscaping
- ✅ Furniture blocking airflow
- ✅ Snow or ice buildup during winter
Simple airflow maintenance often delivers surprisingly large improvements in comfort and efficiency.
❄️ Preparing for Winter Operation
Winter places very different demands on a heat pump than summer cooling does. Instead of removing heat from your home and releasing it outdoors, the system extracts available heat from the outdoor air and transfers it indoors.
Cold, damp conditions can also cause frost to accumulate on the outdoor coil. That's a normal part of heat pump operation, which is why modern systems use automatic defrost cycles to periodically clear the coil and maintain proper heat transfer.
Before winter arrives, it's important to make sure the outdoor unit has clear airflow, the indoor filter is clean, the wall sleeve is properly sealed, and the system is operating normally.
A little preparation helps your heat pump handle cold-weather operation more efficiently and reliably.
I recommend preparing the area around the outdoor unit before temperatures begin to fall. Clear away fallen leaves in autumn, trim shrubs and vegetation when necessary, and make sure the outdoor grille has adequate clearance on all sides.
🧱 Check the Wall Sleeve and Seals
Next, inspect the wall sleeve and the seals surrounding it. Even small gaps that seem insignificant during mild weather can allow cold outdoor air to enter the room throughout winter.
That unwanted air infiltration can reduce comfort and make the heat pump work harder to maintain the temperature you have set.
Look for:
- ✔ Gaps around the wall sleeve
- ✔ Cracked or deteriorated sealant
- ✔ Damaged insulation
- ✔ Loose trim or flashing
- ✔ Signs of moisture intrusion
🔥 Test the Heating Mode Before You Need It
One simple step homeowners often overlook is testing the heating function before cold weather arrives.
When outdoor temperatures are still comfortable and you're not dependent on the heat pump for warmth, switch it to heating mode and let it run long enough to confirm that everything appears normal.
Check that:
- 🌡️ Warm air is coming from the unit
- 🌀 Airflow appears strong and consistent
- 🎛️ The thermostat and controls respond properly
- 🔊 There are no unusual noises or vibrations
- ⚡ There are no unusual electrical smells or repeated breaker trips
You don't need to diagnose mechanical problems yourself. You're simply confirming that the system starts and operates normally.
It's much less stressful to discover a problem in October than on the first freezing night of winter.
Testing the system early gives you plenty of time to arrange professional service if something isn't right—before you actually need the heat pump to keep your home warm.
☀ Preparing for Summer Cooling
The principles of preparation for cooling season are largely the same, but the emphasis is on maximising cooling efficiency and humidity control.
Spring is an ideal time to prepare your through-the-wall heat pump for the cooling season. Before temperatures begin to climb, give the outdoor section a basic cleaning, check the condensate drainage path, and make sure airflow around the outdoor grille is completely unobstructed.
💧 Pay Attention to Condensate Drainage
The condensate drain deserves particular attention because cooling naturally produces moisture. As the evaporator coil removes humidity from indoor air, that water needs to drain safely away from the equipment.
A blocked or restricted drain can cause water to back up and eventually leak into the wall, flooring, or surrounding areas.
And a water leak doesn't necessarily mean there's a problem with the refrigeration system—it may simply be a drainage issue.
Before summer, check for:
- ✔ Obvious debris around the drainage area
- ✔ Standing water or signs of previous leakage
- ✔ A visibly restricted drainage path
- ✔ Water collecting where it shouldn't
If the drain appears blocked beyond what you can safely clear, have it inspected by a qualified HVAC technician.
🧹 Check the Filter and Test Cooling
Clean or replace the air filter according to the manufacturer's recommendations before the system begins operating heavily during summer.
Then run the heat pump in cooling mode and confirm that:
- ❄️ Cool air is being delivered consistently
- 🌀 Airflow appears normal
- 🎛️ The thermostat responds correctly
- 💧 Condensate is draining properly
- 🔊 There are no unusual noises or vibrations
You don't need to perform refrigerant or electrical work yourself. The goal is simply to make sure the system appears ready for the cooling season.
The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) provides industry resources emphasizing proper installation and ongoing maintenance as important factors in achieving the performance and reliability expected from HVAC equipment.
Spring is the time to discover a cooling problem—not during the first major heat wave of summer.
Learn more:
🌎 AHRI Consumer Resources
https://www.ahrinet.org
💧 Don't Forget the Condensate Drain
One maintenance item that can be easily overlooked is condensate drainage system. When your heat pump cools the indoor air, moisture condenses on the evaporator coil and must drain safely away from the unit.
When the condensate drainage path becomes blocked by dirt, algae, dust, or other debris, water can back up inside the cabinet and eventually leak onto nearby walls, trim, or flooring.
I've been called to homes where the homeowner was convinced the air conditioner had developed a serious mechanical problem, only to discover that the actual issue was simply a clogged condensate drain.
💧 A simple drainage check can prevent a surprisingly frustrating problem.
Checking the drain before the cooling season begins gives you an opportunity to identify obvious blockages or signs of water buildup before the system starts operating heavily.
Proper drainage is also essential to the dehumidification process. As the evaporator coil removes moisture from indoor air, that moisture needs a clear and reliable path out of the equipment.
Your heat pump can remove humidity properly only if the moisture it collects can drain away safely.
If you notice persistent water around the unit, repeated drainage problems, or a blockage that you cannot safely clear, it's best to have a qualified HVAC technician inspect the system rather than attempting to disassemble it yourself.
👨🔧 Know Which Jobs Are Best Left to a Professional
I always remind homeowners of one important distinction:
Routine maintenance isn't the same as professional servicing.
There are several basic checks homeowners can safely handle themselves, such as replacing or cleaning the air filter, checking for obvious airflow restrictions, clearing debris around the outdoor grille, and looking for visible signs of damage or water leakage.
However, once you're dealing with refrigerant circuits, electrical testing, compressor diagnostics, or internal components, it's time to bring in a qualified HVAC technician.
🔧 Professional Maintenance Is About Prevention
Professional servicing isn't simply about fixing something after it fails. A major part of its value is finding small problems before they develop into expensive repairs.
Depending on the equipment and manufacturer's recommendations, a professional service visit may include checking:
- ⚡ Electrical connections and components
- ❄️ Refrigeration-system operation
- 🌀 Fan and blower performance
- 🛡️ Safety controls
- 💧 Condensate drainage
- 🌬️ Airflow and coil condition
- 🔧 Overall system operation
I've found loose electrical connections, worn components, restricted coils, and developing airflow problems during routine inspections that homeowners would have had little reason to notice.
Addressing these issues while they're still minor is usually much easier and less expensive than waiting for the heat pump to fail during the hottest or coldest week of the year.
The U.S. Department of Energy's Energy Saver resources recommend regular HVAC maintenance as part of keeping heating and cooling equipment operating efficiently and reliably.
The goal of professional maintenance isn't to guarantee that your heat pump will never break down. It's to give the equipment the best opportunity to operate safely, efficiently, and reliably throughout its service life.
Learn more:
🌎 U.S. Department of Energy – Energy Saver
https://www.energy.gov/energysaver
⚡ Don't Ignore the Electrical System
When homeowners think about heat pump maintenance, they usually think about changing the air filter or keeping the outdoor coil clean. Those tasks are important, but there's another part of the system that often receives far less attention: the electrical system.
Every major component of a heat pump depends on a reliable electrical supply to operate properly. The compressor, fan motors, controls, sensors, and other electrical components all need the correct voltage and connections to function as intended.
Loose electrical connections can create excess resistance and heat, while ageing capacitors, worn contactors, or other deteriorating components can contribute to hard starts, intermittent operation, or unexpected shutdowns.
These aren't components most homeowners should attempt to diagnose or repair themselves. They're exactly the kinds of items a qualified technician can evaluate during professional maintenance.
Homeowners can, however, perform a simple visual inspection before each heating and cooling season. Look at the power cord, plug or receptacle, and the surrounding area for anything unusual.
Watch for:
- ⚡ Discolouration or burn marks
- 🔥 Signs of overheating
- 🔌 Damaged plugs or cords
- 🧵 Exposed or damaged wiring
- 👃 Unusual electrical smells
- ⚠️ Anything that appears loose, melted, or otherwise abnormal
If you notice any of these warning signs, stop using the equipment and have it inspected by a qualified professional.
🚫 Don't Use Extension Cords or Improvised Adapters
There's one shortcut I strongly recommend avoiding: using an extension cord or adapter to power a through-the-wall heat pump unless the manufacturer specifically permits it.
These systems are designed around specific electrical requirements, including voltage, amperage, circuit capacity, and connection methods. Bypassing those requirements can create safety hazards and reliability problems.
When it comes to HVAC electrical systems, the safest approach is simple: follow the manufacturer's requirements and leave electrical diagnosis or modification to a qualified professional.
🌡 Test Both Heating and Cooling Before You Need Them
One of the simplest ways to reduce the chance of an unexpected HVAC problem is also one of the easiest: test your heat pump before the season begins.
In spring, switch the thermostat to cooling mode and let the system run long enough to confirm that it is consistently delivering cool air. In autumn, perform the same check in heating mode before cold weather arrives.
During these preseason tests, pay attention to:
- 🌡️ Consistent heating or cooling
- 🌀 Normal, steady airflow
- 🔊 Unusual noises or vibrations
- 🎛️ Proper thermostat response
- 💧 Any unexpected water or drainage issues
- ⚡ Any unusual electrical smells or repeated breaker trips
I've seen homeowners discover simple issues during these checks—such as an incorrect thermostat setting, a dirty filter, or a minor airflow obstruction—that could be addressed well before extreme weather arrived.
Think of it as a dress rehearsal for your heat pump.
A few minutes of testing before the season begins can give you time to address potential problems before the system has to operate day after day under heavy heating or cooling demand.
📊 Seasonal Preparation Comparison
| Spring Preparation 🌸 | Autumn Preparation 🍂 |
|---|---|
| Clean outdoor grille | Remove fallen leaves |
| Replace air filter | Replace air filter |
| Check condensate drain | Inspect wall seals |
| Test cooling mode | Test heating mode |
| Verify thermostat operation | Prepare for defrost season |
| Schedule annual service | Inspect outdoor clearance |
A little preparation twice each year often provides benefits throughout the following season.
🌧 Protect the Outdoor Unit Year-Round
Because through-the-wall heat pumps remain installed year-round, the outdoor portion is exposed to everything the weather can throw at it—rain, snow, wind, dust, pollen, leaves, and even insects. Over time, that constant exposure can affect the cleanliness and airflow around the equipment.
Fortunately, protecting the outdoor section doesn't require complicated maintenance.
A few simple habits can go a long way.
Keep the area around the outdoor grille clear, remove leaves and debris, trim vegetation that begins to encroach on the unit, and make sure snow or other obstructions don't restrict airflow.
You don't need to dismantle the equipment or perform technical repairs to keep the outdoor section in good condition. The goal is simply to keep it clean, accessible, and able to breathe properly throughout the year.
Keep shrubs and other vegetation trimmed back so air can move freely around the outdoor grille. Clear away fallen leaves before they accumulate, and during winter, gently remove heavy snow from the unit without striking the cabinet, coil, or grille.
After a major storm, take a quick look at the equipment for fallen branches, debris, or other visible damage before operating the system.
🚫 Avoid Blocking the Outdoor Unit
One thing I strongly recommend against is covering a working heat pump with tarps, makeshift covers, or decorative enclosures that restrict airflow.
A heat pump needs adequate airflow during both heating and cooling operation. Restricting that airflow can reduce performance, increase operating time, and place unnecessary stress on the compressor and other components.
The outdoor unit is designed to operate in the weather.
It doesn't need to be wrapped up or enclosed to protect it from normal outdoor conditions. What it does need is clear space, unrestricted airflow, and reasonable care.
Think of it less as protecting the equipment from the weather and more as keeping the environment around the equipment the way its engineers intended it to be.
❌ Common Seasonal Mistakes I See Every Year
After years of working on residential HVAC systems, I've noticed that homeowners tend to make the same seasonal mistakes year after year. The good news is that most of them are easy to prevent.
Some homeowners don't test their cooling mode until the first major heat wave arrives. Others continue using a system with a heavily loaded filter simply because it still appears to be working. I've also seen outdoor units surrounded by patio furniture, overgrown landscaping, storage boxes, and other obstacles that severely restrict airflow without the homeowner realizing it.
Another common mistake is postponing professional maintenance because the system worked perfectly the previous year.
A system that worked well last season still needs regular attention.
HVAC equipment contains mechanical, electrical, and refrigeration components that experience wear over time. Routine inspections can help identify developing problems and keep the system operating as efficiently and reliably as possible.
Fortunately, most of these seasonal mistakes can be avoided with a little planning.
🚫 Avoid These Common Mistakes
- ❌ Waiting for extreme weather before testing the system
- ❌ Ignoring dirty or clogged filters
- ❌ Blocking outdoor airflow with furniture, storage, or vegetation
- ❌ Ignoring unusual noises or changes in performance
- ❌ Skipping recommended professional maintenance
- ❌ Putting off small repairs until they become larger problems
Preventing these problems is usually easier, less disruptive, and less expensive than dealing with them after they develop.
🌱 Small Maintenance Habits Add Up Over Time
One thing I've learned throughout my HVAC career is that long equipment life usually doesn't come from one big maintenance decision.
It's the result of dozens of small habits repeated consistently over the years:
Checking the filter. Keeping the outdoor grille clear. Watching for unusual changes. Testing the system before each season. Addressing small problems before they become major ones.
Good HVAC maintenance isn't about doing everything at once. It's about doing the right small things consistently.
Cleaning a dirty filter. Keeping the outdoor area clear of leaves and debris. Planning professional maintenance. Paying attention to unusual sounds before they become serious. Testing the heating and cooling modes before each season.
None of these tasks is particularly difficult on its own. But together, they create the conditions your heat pump needs to operate efficiently without unnecessary stress on its components.
Modern through-the-wall heat pumps are designed to provide years of dependable heating and cooling. One of the simplest ways homeowners can help them achieve that goal is to keep the equipment operating in the conditions its engineers intended.
That means maintaining clean airflow, keeping the outdoor area unobstructed, following the manufacturer's maintenance recommendations, and addressing developing problems before they become major failures.
Organizations such as ENERGY STAR, AHRI, and ASHRAE emphasize the importance of proper installation, appropriate maintenance, and adequate airflow in supporting HVAC performance and efficiency.
The best maintenance strategy is often surprisingly simple: give your heat pump clean airflow, proper care, and a little attention before small problems have a chance to become big ones
Learn more:
🌎 ENERGY STAR Heating & Cooling
https://www.energystar.gov/products/heating_cooling
🌎 AHRI Consumer Resources
https://www.ahrinet.org
🌎 ASHRAE
https://www.ashrae.org
✅ Homeowner Seasonal Preparation Checklist
Before winter or summer arrives, take a few minutes to go through this checklist:
- ✔ Clean or replace the indoor air filter according to the manufacturer's recommendations
- ✔ Clear leaves, dirt, and debris from around the outdoor grille
- ✔ Trim shrubs and landscaping that could restrict airflow
- ✔ Inspect the wall sleeve and surrounding seals for visible gaps or damage
- ✔ Check the condensate drainage path before and during the cooling season
- ✔ Test heating and cooling modes before each season begins
- ✔ Listen for unusual sounds or vibrations during operation
- ✔ Schedule professional maintenance according to the manufacturer's recommendations
- ✔ Review the owner's manual for model-specific maintenance requirements
- ✔ Address developing problems early rather than waiting for a complete failure
If you've confidently checked most of these items, your through-the-wall heat pump should be better prepared for the season ahead.
👨🔧 Final Thoughts from Jake
One of the things I like about through-the-wall heat pumps is their ability to provide year-round comfort from a single system. They can heat during winter, cool during summer, and provide dependable service throughout the year when they're properly installed and maintained.
Like any mechanical equipment, though, they perform best when homeowners stay ahead of maintenance rather than waiting for something to break.
You don't need to be an HVAC expert or own expensive tools to prepare your system for winter and summer. Much of good seasonal maintenance comes down to the basics:
Clean filters. Unrestricted airflow. Proper drainage. Regular inspections. Professional service when needed.
These simple habits can help support efficient operation, reduce unnecessary stress on the equipment, and give your heat pump the best opportunity to provide reliable comfort season after season.
When homeowners ask me what the secret is to getting the longest possible service life from their heat pump, my answer is always the same:
Don't wait for a problem before you start taking care of the system.
A few minutes of preparation before each season can help catch small problems before they become expensive repairs.
In HVAC, a little preventive attention today can save you a lot of trouble tomorrow.
Jake Lawson
HVAC Insights Specialist
Factory Furnace Outlet
Next Blog: Is a Through-the-Wall Heat Pump a Good Choice for Home Offices, Sunrooms, and Additions?