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Indoor Air · RepairHRV & ERV Repair
HRV and ERV repair covers the five faults behind most calls: a failed fan motor, a stuck defrost damper, a core frozen solid, a blocked condensate drain and a dead wall control. The diagnostic visit is $90–$150 and the repair is quoted in writing from there. Repair makes sense while parts are still made for the model and the core is intact; a unit past about 15 years with a damaged core or a discontinued motor is a replacement.
A ventilator has two fans, one core, a damper and a small control board, so the fault list is short, and it sits inside our indoor air quality work. A fan motor fails at the bearings first: it growls, then seizes, and the unit keeps running on the other fan alone. That leaves the house on exhaust only or supply only, which is the start of comfort complaints people rarely connect to the ventilator (why an HRV gets noisy).
Winter faults centre on defrost. A few degrees below freezing, moisture in the outgoing air frosts the core, and most units clear it by closing a motorised damper on the outdoor intake and recirculating warm house air. When the damper actuator sticks open or the temperature sensor fails, the frost never clears and the core becomes a block of ice; when the damper sticks shut, the unit recirculates all winter and brings in no outdoor air at all. Our answer on why an HRV freezes up covers what to check first.
Water on the floor under the unit is usually the drain. The pan collects condensate and defrost melt, and a kinked tube, a slimed trap or a line run uphill sends it out the cabinet seams instead. A dead wall control is often wiring: a low-voltage conductor broken at a staple, or a control that has lost its link to the board. We run the unit from its own terminals before condemning either part.
Flow imbalance is the fault with no broken part. If exhaust outruns supply, the house runs negative: cold draughts at outlets and door sills, and a pull on the flue of a natural-draft water heater. If supply outruns exhaust, moist air is pushed into wall cavities, and a unit moving too little air either way leaves windows running with condensation. Measuring both streams and resetting the dampers is part of every repair, and a unit that is only dirty needs cleaning and balancing instead.
Call for HRV or ERV repair when
- One airstream is dead: air at the supply grilles but none at the bathroom exhausts, or the reverse
- The core is iced over, or frost is growing on the cabinet and the cold-side ducts
- Water is dripping from the unit or staining the floor beneath it
- The wall control is blank, or pressing its buttons changes nothing at the unit
- The unit growls, squeals or vibrates, and the noise changes with fan speed
How it works
Tell us the make and model, what the wall control shows, and whether there is ice, water or noise. If the core is frozen or the cabinet is leaking, unplug the unit and let it thaw into a tray; the house will be fine without it for a few days.
Each fan is run on its own, the damper is driven through its travel, the defrost sensor is checked against a thermometer and the drain is tested with water. The price is written down before any part is ordered.
After the repair, both airflows are measured and the dampers reset. If the motor or board is no longer made, or the core is cracked, you get the cost of a new unit beside the cost of the repair so you can choose; send us the model number to start.
Brands: We repair Venmar and Lifebreath units along with the other residential HRV and ERV makes found in Halton and Hamilton homes.
Common questions
Is it safe to leave a broken HRV switched off?
For days, yes; for the whole winter, no. A tight house without ventilation builds humidity, cooking odours and carbon dioxide, and the windows will tell you first. The exception is a unit running on its exhaust fan alone in a house with a natural-draft water heater or a wood fireplace: turn that unit off until it is repaired, because it is pulling the house negative.
Should I repair or replace a 15-year-old HRV?
Check two things: whether the manufacturer still supplies the motor and control board, and whether the core is sound. A motor on a supported model is a sensible repair at any age. A cracked, warped or delaminated core, or a discontinued board, on a unit past 15 years means the money is better put toward a new HRV or ERV, and newer cores recover more heat.
Why are my windows wet with the HRV running?
Either the unit is moving far less air than it should, or it is stuck in recirculation. A seized exhaust fan, a blocked outdoor hood, a defrost damper jammed shut or a control left on a low intermittent setting all leave moisture in the house. Airflow measured at the unit shows which one it is, and the repair follows from that reading.
Can a frozen HRV core be saved?
Usually. Unplug the unit, let the core thaw fully over a tray, and check that the drain runs. Aluminium and polypropylene cores survive a freeze unless ice has split the plates. The real repair is finding why defrost failed: the damper actuator, the sensor, the board, or an airflow imbalance that sends more cold air across the core than the exhaust stream can keep warm.
Do you need to come out if only the wall control is dead?
Not always. Check that the unit is plugged in, its door is fully latched (many have a door safety switch) and the breaker is on. If the unit runs from its own switch or terminals but ignores the wall control, the fault is the control or the low-voltage wire between them, and that is a short visit, not a major repair.