How do I maintain my HRV unit and filters in a Toronto home?

Maintaining your HRV is one of the most important and most neglected tasks in a GTA home — a clean, well-maintained unit runs efficiently and delivers fresh air, while a neglected one wastes energy, circulates poor-quality air, and fails years before its time. The good news is that HRV maintenance is straightforward, takes about 30 minutes per session, and is entirely within a homeowner's ability.

Filters should be cleaned or replaced every 3 months — more frequently if you have pets, live near a busy road, or notice reduced airflow. Most HRV units have two filters: one on the incoming fresh air side and one on the outgoing stale air side. Many units use washable foam or synthetic mesh filters that can be vacuumed and rinsed with warm water, then allowed to dry completely before reinstalling. Some higher-end units use disposable pleated filters that need replacement. Check your owner's manual to confirm which type your unit uses. Replacement filters typically cost $15-$40 per set. Running your HRV with dirty, clogged filters is one of the most common maintenance failures in Toronto homes — airflow drops dramatically, the unit works harder, the motors run hotter, and your home's ventilation suffers.

The heat exchanger core needs cleaning once or twice per year — ideally in the fall before the heating season begins and again in the spring. Remove the core from the unit (it slides out on rails in most models), then soak it in warm water with a mild dish soap for 15-20 minutes. Gently rinse it under running water, shake off excess water, and allow it to dry completely before reinstalling. The core is where heat transfer happens between the outgoing and incoming air streams, and dust buildup on the core surfaces reduces heat recovery efficiency. A dirty core means colder incoming air in winter and higher heating bills.

Drain pans and condensate drains require attention every 3-6 months. During Toronto's heating season, moisture condenses inside the HRV as warm, humid indoor air passes over the cold core surfaces. This condensation collects in a drain pan and exits through a small drain tube. If this drain becomes clogged with dust, mould, or mineral deposits, water backs up inside the unit and can overflow, causing water damage and creating a mould-friendly environment. Flush the drain line with warm water and check that water flows freely to the floor drain or condensate pump.

Exterior intake and exhaust hoods need seasonal inspection. This is especially critical in Toronto's climate. In winter, check for ice buildup or snow blockage after every major storm — a blocked intake starves your home of fresh air, while a blocked exhaust can cause the unit to shut down on high pressure. After fall leaf drop, check for leaves and debris covering the hoods. In summer, check for bird nests or wasp nests in the hoods — both are common in the GTA. The intake and exhaust hoods should have screens to prevent insects and animals from entering, but verify these screens are intact.

Interior supply and exhaust grilles should be vacuumed every 3 months. Bathroom and kitchen exhaust grilles accumulate dust, lint, and grease that restrict airflow. Fresh air supply grilles in bedrooms and living areas also collect dust. A quick vacuum with a brush attachment keeps air flowing freely.

Most HRV units last 15-20 years with proper maintenance. If your unit is approaching that age and you notice reduced airflow despite clean filters, unusual noise from the motors, or frost forming on the core during moderate winter temperatures (above -10 degrees), it may be time for replacement. Budget $2,500-$5,000 for a new HRV unit installed in a typical Toronto home.