When temperatures rise in Ottawa, your AC becomes essential for keeping your home comfortable. But if your air conditioning system suddenly stops cooling and you notice ice forming on the coils, it can be both confusing and frustrating. An AC freezing up might seem like something that only happens in colder weather, but it’s actually a common issue during peak summer months. Left unresolved, it can lead to serious breakdowns or expensive repairs.
One of the biggest problems with a frozen AC is that it usually doesn’t just fix itself. If ignored, the ice buildup can damage internal components like the compressor or blower motor. That’s why it’s important for homeowners in Ottawa to pay attention to the early signs and take steps to address the problem quickly. Here’s what could be causing it and how to get your system back on track before the next heatwave hits.
Why Your AC Freezes Up in Summer
Even though summer in Ottawa can bring very hot conditions, it’s surprisingly common for AC systems to freeze. This usually happens when something affects airflow or the cooling cycle, preventing warm air from circulating properly through the system. Instead of pulling moisture and heat out of your home, the refrigerant becomes too cold and starts to freeze the moisture that’s present around the coils. Before long, ice starts to build up and your system can’t cool effectively.
A frozen AC doesn’t just stop doing its job. It also works under heavier stress, which can lead to more wear and tear. That stress can shorten the unit’s lifespan and raise your energy bills. Common reasons for this summer freeze-up include:
– Poor airflow due to a dirty filter
– Low refrigerant levels causing the coil to get too cold
– Blocked or closed vents restricting circulation
– Faulty or incorrectly set thermostats sending the wrong signals
Addressing these causes early can help save time, money, and discomfort later in the season. One quick check many homeowners can do involves checking the condition of the AC filter.
Check Your Air Filter
One of the easiest things to overlook is also one of the most important. A clogged air filter can choke your AC’s airflow and set off a chain reaction that ends with frozen coils. When air can’t move freely through the system, the evaporator coil gets too cold, and condensation freezes on it instead of evaporating. That layer of ice just keeps building until the system can barely operate.
To prevent this, checking your air filter regularly is a good habit, especially during the summer when your AC runs longer hours. Here’s how to stay ahead of it:
1. Turn off the system before inspecting the filter.
2. Locate the filter, usually found behind the return air grille or inside the indoor air handler.
3. Hold the filter up to the light. If you can’t see light clearly through it, it’s time to replace it.
4. Replace disposable filters with the same size and type, or clean permanent filters as directed by the manufacturer.
5. Set a reminder to check the filter every 30 days during heavy use.
A homeowner in Ottawa once told our technicians that their AC stopped blowing cold air after just a few exceptionally hot days. When we looked, their filter hadn’t been changed in months. Ice covered most of the coil, and the unit had to be shut down for several hours before repairs could begin. A quick filter replacement would’ve saved them time and kept their home cool when they needed it most.
Inspect Air Vents and Registers
If your AC filter is clean but freezing still occurs, the next thing to investigate is your vents and registers. These openings play a direct role in how air moves through your system. When vents get blocked by furniture, curtains, or dust buildup, or when registers are tightly closed, the airflow becomes unbalanced. That poor circulation leads to low pressure in the ducts, which eventually causes the inner components to work harder than intended.
To keep air moving smoothly and avoid freezing:
– Walk through your home and check all supply and return vents.
– Make sure no vents are closed or covered by household items.
– Use a vacuum cleaner attachment to remove dust that may be collecting in or around the vent covers.
– If airflow seems uneven from room to room, there may be a duct issue that needs inspection by our technicians.
Small blockages in airflow may not seem like a big deal, but together they can bring your indoor comfort to a stop. Frozen coils, longer cooling cycles, and reduced indoor air quality often follow. Vent care is simple, but it can go a long way in preventing major AC repair issues in Ottawa during the hottest part of the year.
Examine Refrigerant Levels
If you’ve already confirmed that your filters and vents are clear but your AC is still freezing, it may be a refrigerant issue. Refrigerant is responsible for absorbing heat from the air in your home. When levels are too low, usually due to a leak, the pressure in your AC system drops. This causes the temperature inside the evaporator coils to fall too low, freezing the moisture that collects on them.
Since refrigerant operates under pressure and plays a critical role in cooling performance, this is not something to handle without training. Trying to inspect or refill refrigerant on your own can lead to incorrect levels, chemical exposure, or equipment damage. Instead, it’s important to have our professionals check for leaks, repair them, and recharge the system to manufacturer specifications. They’ll also ensure that your system isn’t suffering additional damage caused by running while frozen, like compressor strain.
Many homeowners don’t know there’s a leak until the coils start frosting over. You may also notice your home isn’t getting as cool as it used to, despite the system running longer. If you see any of those signs, especially ongoing freezing after you’ve checked airflow, scheduling an inspection to test the refrigerant level is the next step.
Monitor Thermostat Settings
Your thermostat helps regulate temperature and manage the cooling cycle. If set too low or programmed incorrectly, it can cause your AC to work harder than necessary. Over time, longer run cycles without proper airflow or rest can lead to the evaporator coil freezing.
This is especially true during peak summer heat in Ottawa, when it may seem tempting to set the temperature to 65 degrees or below to cool the house faster. But extreme settings don’t make the system cool quicker. They only push it harder over a longer period. Instead, set the temperature at a reasonable level and be patient while the system adjusts.
Here are some tips for setting your thermostat correctly and avoiding errors that can lead to freezes:
– Set the thermostat between 72-76 degrees for efficient cooling.
– Avoid sudden drastic temperature drops; lower settings gradually if needed.
– Use a programmable thermostat so your system runs on a consistent, balanced schedule.
– Double-check that the fan setting is on Auto instead of On to prevent continuous airflow across already cooled coils.
– If your thermostat isn’t responding or showing incorrect readings, it may be time for a replacement or recalibration.
A homeowner in Ottawa mentioned they had a new programmable thermostat but were still seeing ice on their unit. Our technicians found that the fan was set to run continuously, even when the system wasn’t actively cooling. That constant air movement helped ice form over time. Once the settings were fixed, the issue stopped.
Keep Your AC Running Smoothly This Summer
A frozen AC during the middle of summer can interrupt your comfort and put your entire cooling system at risk. Most freezing problems start with small, fixable issues such as dirty filters, blocked vents, low refrigerant, or incorrect thermostat settings. Catching those early, before they lead to heavy ice buildup, protects both your unit and your energy bill.
Homeowners in Ottawa can stay ahead of AC problems by being proactive. Make a habit of checking filters and vents each month, avoid pushing the system too hard, and keep an eye on performance changes. If the unit starts freezing often, makes strange sounds, or blows warm air, that’s the right time to bring in our technicians to handle it properly.
Staying cool all summer long takes a little attention and regular upkeep. When you notice early cooling issues, taking action quickly helps avoid bigger failures in the middle of a heatwave. Remember, the sooner an AC freezing issue is handled, the better your home will feel and the longer your system will last.
If your AC continues to freeze up despite proper maintenance, the professionals at All Seasons Air Conditioning and Heating are ready to help resolve the issue before it becomes more serious. Learn more about AC repair in Ottawa to keep your cooling system running efficiently all summer. For a quick estimate or to book a service visit, please contact us today.
