Most Outdoor Water Is Normal
Here's the reassuring news first: a heat pump's outdoor unit is designed to produce water, and water around it is usually nothing to worry about. The outdoor unit's whole job is to exchange heat with the outside air, and that process naturally creates condensation and meltwater that drips out the bottom by design.
In winter, an outdoor heat pump frosts up — that's expected — and periodically runs a defrost cycle that melts the frost so the unit keeps working. All that melted frost runs out the bottom of the cabinet, often as a fairly noticeable puddle. In cooling mode during humid summer weather, the outdoor or indoor coil also sheds condensation.
So if you walk past your outdoor unit on a cold morning and find water or even a thin sheet of ice underneath, your heat pump is most likely doing exactly what it's supposed to.
When It Runs Defrost (and Why That's Good)
Understanding the defrost cycle clears up most outdoor-water worries. In our damp Lower Mainland winters, frost builds up on the outdoor coil as the unit pulls heat from cold, moist air. If that frost were left to accumulate, it would block airflow and cripple the system.
So every so often, the heat pump briefly reverses itself to warm the outdoor coil and melt the frost. You might notice steam rising from the unit, a whoosh as the cycle starts, the fan stopping for a few minutes, or a sudden release of water underneath. All of that is normal and healthy — it means the defrost system is working.
That steam and meltwater can look dramatic, but it's just frost turning to water and vapour. A heat pump that frosts heavily and never seems to defrost, on the other hand, may have a defrost fault worth checking.
Signs the Outdoor Leak Is a Problem
Some outdoor water situations do warrant attention. Constant heavy water in any season, including dry summer days with no cooling running, suggests something beyond normal condensation.
Water pooling against the house, a window well, or a walkway is a problem not because of the leak itself but because of where it's going — it can seep toward your foundation or refreeze into a slip hazard. The unit should sit on a pad that lets water drain away.
Heavy, persistent ice that doesn't clear — a unit encased in ice rather than lightly frosted, or one that stays iced for days — points to a defrost problem, low refrigerant, or restricted airflow.
An oily residue with the water, or a hissing sound from the unit, can indicate a refrigerant leak, since refrigerant carries trace oil. That's a certified-technician issue.
Water combined with the unit not heating well ties the leak to a performance fault rather than ordinary drainage.
Drainage and Placement in BC
In Greater Vancouver, where outdoor units run through wet, frosty winters, placement and drainage make a real difference. An outdoor unit should be raised on a pad or stand so meltwater drains freely away from the cabinet and the building, rather than pooling underneath where it can refreeze and ice up the unit's base.
Units set directly on a flat patio, in a low spot, or tight against a wall are most prone to pooling and ice buildup. Clearing leaves, snow, and debris from around the unit helps water drain and air circulate. If you notice meltwater consistently running toward your foundation or freezing across a walkway, it's worth having the placement and drainage assessed.
None of this means anything is broken — good drainage is mostly about where the unit sits and keeping the area clear.
Not Sure? Call CanroHeat
Heat pumps for GasBoilers.ca are serviced by our parent company, CanroHeat, with technicians across Greater Vancouver. If you can't tell whether your outdoor water is normal defrost runoff or a genuine fault — or if you're seeing constant water, persistent ice, an oily residue, or weak heating — call 604-359-1081.
A technician can quickly confirm whether the unit is simply doing its normal defrost work or whether the defrost system, refrigerant charge, or drainage needs attention. There's no harm in asking; it's better to confirm a puddle is harmless than to overlook a developing problem. Call 604-359-1081 if you'd like peace of mind.