First, Where Is the Water Coming From?
Heat pumps move heat by running refrigerant through coils, and that process naturally produces water. Whenever warm, humid air passes over a cold coil, moisture condenses out of it — exactly like the beads of water on a cold glass of iced tea on a summer afternoon. So a certain amount of water is completely expected.
The question that matters is where the water shows up and how much there is. A few drips from the outdoor unit during a cold snap, or a steady trickle from the condensate line of an indoor air handler in cooling mode, is usually normal. Water pooling on your floor, dripping from a ceiling, running down a wall, or gushing from the outdoor unit is not normal and points to a fault that needs attention.
Before you panic, take a moment to trace the water back to its source. That single observation tells a technician more than almost anything else.
The Most Common Causes of a Leaking Heat Pump
1. A clogged condensate drain line. This is by far the most frequent cause of indoor water. The drain line carries condensation away from the indoor coil. Over months and years it collects dust, algae, and slime that eventually block the pipe. When water can't drain, it backs up and overflows the drain pan.
2. A cracked or rusted-out drain pan. The pan under the indoor coil catches condensation. If it cracks (often from age) or rusts through, water drips straight onto whatever is below.
3. A frozen coil that's now melting. Low refrigerant, a dirty filter, or poor airflow can cause the coil to ice over. When the system shuts off or defrosts, all that ice melts at once — far more water than the drain can handle.
4. A failed condensate pump. Some indoor units sit below the drain line and rely on a small electric pump to push water out. When that pump fails, water has nowhere to go.
5. A refrigerant leak. Low refrigerant lowers coil temperature and causes excessive icing and, eventually, melting and dripping. This one is different from the others — it requires a certified technician and is covered in detail in our refrigerant-leak guide.
Why BC Homes See This More Often
Greater Vancouver's damp, humid climate means heat pumps here pull a lot of moisture out of the air, especially during the muggy stretches of late summer. More humidity means more condensation, which means drain lines fill with water more often and clog faster than they would in a dry interior climate.
Our mild but wet winters also create heavy frosting on outdoor units. A properly working heat pump runs a defrost cycle to melt that frost, and the meltwater drips out the bottom — that's normal. But if the defrost cycle is faulty, or if the unit sits in a spot where meltwater can't drain away (against a wall, in a window well, or on a flat patio with no slope), water can pool and even refreeze into a hazard.
The takeaway: some water around a Lower Mainland heat pump is just our climate at work. The trick is knowing when the amount or location crosses the line into a real problem.
What You Can Safely Check Yourself
A few simple checks are safe for any homeowner. First, replace or clean the air filter if it's dirty — a clogged filter restricts airflow and is a leading cause of coil freezing. Second, make sure the outdoor unit has clear space around it so meltwater can drain and air can circulate; clear away leaves, snow, and debris.
Third, look at where the condensate drain line exits. If you see standing water in the drain pan or a line that isn't dripping when it should be, the line is likely clogged. Some homeowners gently pour a cup of warm water with a little vinegar through the drain access to help clear early slime — but only if you can do so safely and can see what you're doing.
What you should not do: open the sealed refrigerant system, handle refrigerant lines, or try to recharge the unit. That's both dangerous and, in Canada, restricted to certified technicians. If your simple checks don't solve it, it's time for a professional.
When to Call CanroHeat
Heat pumps at GasBoilers.ca are serviced by our parent company, CanroHeat, whose technicians handle heat pumps, furnaces, and water heaters across Greater Vancouver. If your heat pump is leaking water indoors, freezing repeatedly, or losing heating and cooling performance, give CanroHeat a call at 604-359-1081.
A technician will trace the leak to its source, clear or repair the drain system, check refrigerant levels with proper instruments, and confirm the unit is draining and defrosting correctly. Catching a small leak early — a clogged line or a tired condensate pump — is far cheaper than letting water damage your floors, drywall, or the unit itself. Call 604-359-1081 to book a visit.