Maintenance in extreme cold

What an owner can actually check

• The filter. NRCan says change or clean it about every three months. A loaded filter cuts airflow and efficiency. NRCan
• Supply and return grilles. Furniture and rugs on top of them shorten equipment life, for the same airflow reason.
• Snow and ice around the outdoor unit. The coil has to see air. A unit buried to the fan is not “in defrost.” Clear the drift, and do not chip ice off the fins with a tool.
• The outdoor unit sitting level on its stand, with the drain path under it able to drop meltwater instead of building a rink on the pad.
• The backup. An oil tank gauge, a propane regulator covered in ice, a wood stove that has not been swept. The heat pump page is not a substitute for that maintenance.

What stays with a technician

NRCan recommends an annual visit from a qualified contractor. Refrigerant charge, electrical connections, combustion analysis on the backup, and defrost controls are that visit. A homeowner does not add refrigerant. If the system uses R-454B or R-32, the technician needs to be set up for that mildly flammable class. See the refrigerant page.

Steam off the outdoor unit in cold weather is usually defrost. A unit that never heats, or that ices into a solid block and stays there, is not usual. That is a service call, not a deeper snowbank.