By Jake Lawson
One of the most common pieces of advice I like to give homeowners when it comes to HVAC equipment is that you shouldn’t wait until the weather changes to think about your heat pump. Every year I get calls the first hot day of summer or the first cold night in winter from people whose system just stopped working like they thought it should. It's usually not a big mechanical problem. The equipment just wasn't ready for the upcoming season.
One of the benefits of a through-the-wall heat pump is that it provides both heating and cooling from one unit. It’s a great year-round comfort solution for homes, apartments, vacation properties and additions. However, it is used more constantly than equipment that just cools during summer, as it works throughout every season. A little preventative attention before each season can go a long way towards improving efficiency, reducing wear and helping the system deliver consistent comfort year round.
The good news is that getting ready for the seasons doesn’t have to be complicated. Most homeowners can perform a few simple inspections themselves, leaving electrical work and internal servicing to qualified HVAC professionals. I’ve learned that it is much better to spend thirty minutes checking a system before the temperatures get extreme than to spend hours waiting for emergency service while everyone else in town is trying to get repairs at the same time.
In this guide, I’ll walk you through the seasonal maintenance steps I recommend before winter and before summer, tell you why each step is important, and help you figure out which tasks are right for homeowners and which are best left to trained technicians.
🌤 Why Seasonal Preparation Matters
One thing I hear a lot is that if a heat pump was working well last season, it will work just as well the next. That is certainly possible, but HVAC systems operate under changing conditions throughout the year. Dust builds up, debris from outside gathers around the condenser, filters become clogged and the weather slowly destroys seals, insulation and drainage parts.
By preparing your system before the seasons change, you can catch these small issues before they turn into bigger problems. Even something as simple as a dirty air filter or blocked outdoor grille can cause the compressor to run longer, using more electricity and putting unnecessary stress on parts that are built to last for many years.
Seasonal inspections also help avoid unpleasant surprises for homeowners. There’s never a good time to discover that your heat pump isn’t heating properly during the first cold snap of winter — or cooling efficiently during a summer heat wave. Pre-checking your equipment gives you time to schedule maintenance before HVAC contractors are swamped with emergency calls.
The U.S. Department of Energy recommends regular maintenance of heating and cooling equipment because proper maintenance improves efficiency, supports reliable operation, and can help extend equipment life.
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 just show up to do a seasonal service appointment and start ripping the unit apart every time. Instead I spend a few minutes just looking at the whole installation.
Homeowners can pretty much do the same thing.
Walk around the equipment and inspect the inside and outside parts of the through-the-wall unit. Look for anything that looks different from last season. Is landscaping growing up around the outdoor grill? Are leaves, dirt or cobwebs blocking airflow? Any signs of water staining, loose trim, insulation damage or gaps around the wall sleeve?
And many possible problems show up during that first look, long before any special tools are required. Slow is good and careful inspection before turning on the equipment has uncovered loose outside grilles, bird nests, damaged weather sealing, blocked condensate drains and deteriorated insulation.
This is not for the purpose of diagnosing complex mechanical problems. “Just to see if there’s any obvious things that could interfere with efficient operation during the coming season.
🌬 Clean Airflow Is the Foundation of Performance
If you've read several of my articles, you've probably noticed that I mention airflow repeatedly. There's a good reason. Almost everything inside a heat pump depends on moving the proper amount of air.
During cooling season, unrestricted airflow allows the evaporator coil to remove both heat and humidity efficiently. During winter, proper airflow helps the refrigeration system absorb available outdoor heat while maintaining comfortable indoor temperatures. When airflow becomes restricted, the system simply has to work harder to achieve the same results.
One of the first things I recommend each season is checking both the indoor air filter and the outdoor grille. Dirty filters reduce indoor airflow, while leaves, grass clippings, snow, or landscaping can restrict airflow on the outdoor side. I've visited homes where replacing a heavily clogged filter immediately improved heating performance without replacing a single mechanical component. That's because the system was finally able to move air the way it was originally designed.
The ENERGY STAR® program also emphasizes the importance of maintaining clean filters as one of the easiest ways homeowners can improve HVAC efficiency.
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
In winter a heat pump has different requirements than in summer. Instead of dumping heat to the outside, the system captures available heat from the cold outside air, while controlling frost buildup with periodic defrost cycles.
I’d recommend cleaning up the outside area before the temperatures begin to fall. Clean up fallen leaves in the autumn, prune shrubs when needed and make sure the outdoor grill has proper clearance all around.
Next, check the wall sleeve and the seals around it. Even small gaps that may seem insignificant during a mild spell can allow cold outdoor air to infiltrate the room all winter long, reducing your comfort and making your heat pump work harder than it needs to.
Homeowners frequently overlook a simple step: testing the heating mode before cold weather arrives. When the outdoor temperature is still comfortable enough that you’re not relying on the system, turn it on. When starting up, check that there is good warm air flow, controls are functioning properly, and no strange noises are present.
Usually it is a lot less stressful to find a problem in October than it is to find one on the first freezing night of the year.
☀ 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 a great time to do some cleaning of the outdoor section, checking the condensate drain path and making sure warm air can freely escape from the outdoor grille. The condensate drains need special attention because they are responsible for safely removing the moisture collected while cooling your home. A blocked drain can eventually lead to water leakage that has nothing to do with the refrigeration system itself.
Clean or replace the air filter before you start using the house heavily in the summer. While you’re at it, run the unit in cooling mode long enough to be sure it’s delivering cool air consistently and that the thermostat is responding properly.
According to the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), HVAC equipment can provide the performance manufacturers expect throughout its service life, with good installation and consistent maintenance.
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 that drainage route is obstructed by dirt, algae, or debris, water can back up within the cabinet and eventually drip into nearby walls or flooring. I’ve been on service calls where the homeowner thought the air conditioner itself was broken, when in fact it was just a clogged drain.
Checking for proper drainage before the cooling season begins helps prevent these unnecessary problems and allows the equipment to remove humidity as efficiently as it was designed to.
👨🔧 Know Which Jobs Are Best Left to a Professional
I always try to remind homeowners of one thing: routine maintenance is not the same thing as professional servicing. Homeowners can safely do a lot of simple inspections, such as replacing filters, checking the airflow, cleaning around the outdoor grille, or looking for obvious signs of damage. But when you start working with refrigerant systems, electrical testing, compressor diagnostics, or internal component inspection, it’s time to call in a qualified HVAC technician.
Professional maintenance does more than just fix. Much of the value is in catching little things before they become big, expensive repairs. During a routine service visit, technicians typically check electrical connections, test refrigerant performance, check the fan motors, test safety controls, check condensate drainage and ensure the heat pump functions according to the manufacturer’s specifications.
I’ve often found loose electrical terminals, worn capacitors or partially restricted coils during annual inspections that homeowners never would have noticed themselves. Dealing with these problems early usually costs a lot less than waiting until the system stops working during the hottest or coldest week of the year.
The U.S. Department of Energy recommends regular professional maintenance as part of an overall plan to keep heating and cooling equipment operating 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 typically think of filters or outdoor coils. Every major component requires a stable electrical supply but the electrical system is often far less attended to.
Loose electrical connections can cause high resistance and heat, and ageing capacitors or worn contactors can cause hard starts or intermittent operation. These aren’t things most homeowners should try to diagnose, but they’re exactly the kinds of components technicians check during routine maintenance.
I also recommend that you visually inspect the power cord, receptacle, and the area around it before every heating and cooling season. If you see any signs of discolouration, overheating, damaged wiring, or anything that just looks wrong, stop using the product and have it professionally checked out.
I would strongly caution against one shortcut, and that is the use of extension cords or adapters with through-the-wall heat pumps. These systems are designed by the manufacturers for specific electrical requirements, and bypassing those requirements can have safety and long-term reliability implications.
🌡 Test Both Heating and Cooling Before You Need Them
One of the simplest ways to avoid emergency repairs is something that only takes a few minutes. Just run the system in the heating and cooling modes before the season starts. In the spring, switch the thermostat to cooling and let the unit run long enough to confirm it's consistently delivering cool air. Do the same check in autumn using heating mode. Listen for weird noises, check that the airflow feels normal, and make sure the controls respond properly.
During these preseason tests I have seen homeowners find simple thermostat settings, dirty filters or small airflow restrictions that were easily corrected before outdoor temperatures became extreme. It’s like a dress rehearsal for your heat pump before it has to perform every day for the next several months.
📊 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
Since through-the-wall heat pumps sit in place all year long, the outdoor portion is exposed to all types of weather you can think of. Rain, snow, wind, dust, pollen, leaves and even insects all take their toll on the equipment over time.
Luckily, there is no complicated maintenance that you need to do to protect the outdoor unit.
Keep shrubs trimmed back so air can flow freely. Remove leaves before they build up around the grille. In winter, gently remove heavy snow from the unit without striking the cabinet or coil. Do a quick visual check after a big storm to see if branches or other debris have damaged the equipment.
The only thing I would advise against is putting tarps or decorative enclosures over a working heat pump that restrict airflow. These systems require free flow of air in heating and cooling seasons. Less air flow means less efficiency and unnecessary stress on the compressor.
It’s not to protect the equipment from the weather. It's designed to operate in the clean, open environment that the engineers developed it for.
❌ Common Seasonal Mistakes I See Every Year
Years of experience working on residential HVAC systems has taught me that the same seasonal mistakes are made time and time again. The good news is nearly all of them can be prevented.
Some homeowners don’t even bother to try out cooling mode until the first heat wave hits. Other people ignore dirty filters because the equipment still seems to be working. I’ve also seen outdoor units hemmed in by patio furniture, landscaping or stacked storage boxes that block airflow so badly the homeowner doesn’t even realise.
Another surprisingly common mistake is to skip or delay professional maintenance just because the system was working well last year. HVAC equipment doesn’t cease to require maintenance after it’s installed. As with any mechanical system, routine inspections are still one of the best ways to maintain efficiency and reliability over time.
Fortunately, these are problems that can easily be avoided with a little planning and seasonal attention.
🚫 Avoid These Common Mistakes
- ❌ Waiting until extreme weather arrives
- ❌ Forgetting to replace dirty filters
- ❌ Blocking outdoor airflow
- ❌ Ignoring unusual noises
- ❌ Skipping annual maintenance
- ❌ Delaying small repairs
Preventing these issues is usually much easier—and less expensive—than correcting them later.
🌱 Small Maintenance Habits Add Up Over Time
One thing I like to tell homeowners is that long equipment life is usually not the result of one big decision. Rather, it’s the culmination of dozens of tiny maintenance habits consistently done over many years.
Cleaning dirty filters. Keeping the outdoor area litter-free. Annual service planning. Listening for unusual sounds before they become serious. Testing heating & cooling during pre-season. None of these individual tasks are particularly difficult, but they do add up to an environment in which the heat pump can operate efficiently with less unnecessary strain on its parts.
Modern heat pumps that go through the wall are built for many years of dependable service. One of the simplest things we can do to help them reach that goal is to give them the conditions they were designed for.
Organizations such as ENERGY STAR, AHRI, and ASHRAE all emphasize that proper installation, routine maintenance, and unrestricted airflow are fundamental to long-term HVAC performance.
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 review the following:
- ✔ Clean or replace the indoor air filter
- ✔ Remove leaves, dirt, and debris from the outdoor grille
- ✔ Check that shrubs and landscaping don't restrict airflow
- ✔ Inspect the wall sleeve and surrounding seals
- ✔ Verify condensate drains freely during cooling season
- ✔ Test both heating and cooling modes before the season begins
- ✔ Listen for unusual noises during operation
- ✔ Schedule annual professional maintenance
- ✔ Review the owner's manual for seasonal recommendations
- ✔ Address small problems before they become expensive repairs
If you can confidently check off most of these items, your through-the-wall heat pump is likely well prepared for the season ahead.
👨🔧 Final Thoughts from Jake
Another reason I like through-the-wall heat pumps is they are designed to deliver year-round comfort. They are heat in the winter, air conditioners in the summer and steady year-round appliances when they get the attention they deserve. As with any piece of mechanical equipment, they work best when they’re kept up with small maintenance rather than waiting until something breaks.
You don’t need to be a technical wizard or have expensive tools to get your system ready for winter and summer. Much of it boils down to paying attention to the basics — clean filters, unobstructed airflow, proper drainage, routine inspections and professional maintenance when it’s needed. Such simple habits help reduce unnecessary wear, improve efficiency and give the equipment the best shot at providing reliable comfort season after season.
When homeowners ask me what is the secret to getting the longest life possible out of their heat pump, I always tell them the same thing. Don’t wait for a problem to start taking care of your system. A little bit of prep work before each season can often prevent the biggest problems down the road and is one investment that almost always pays for itself.
Jake Lawson
HVAC Insights Specialist
The Furnace Outlet
