There’s mould in your heat pump. Here’s what it’s costing you.
If you have a heat pump in Atlantic Canada, there is a good chance it has mould in it right now. Not because something has gone wrong. But because that’s what heat pumps do.
It’s not the kind of mould you can see from across the room. It builds up deep inside the unit, on the blower wheel and in the coils. It’s invisible behind the casing, circulating through the air in your home every time the system runs.
And beyond the health question, it’s costing you money on every electricity bill.
Pure Air Heat Pump Cleaning has spent a decade in Nova Scotia opening up these machines and cleaning out what’s inside. What the company finds, almost without exception, is mould.
How it gets there
Heat pumps pull moisture out of the air whenever they run in cooling or dehumidify mode. That moisture moves through the unit and some of it settles on the blower wheel (that cylinder at the center of the machine that pushes air through your home). Moisture sitting on a spinning wheel in a warm, enclosed space breeds mould. By the time you’re running the heat pump for winter heating, you’re running that air through mould-coated components on a continuous loop.
The problem compounds quickly in Nova Scotia’s humid summers. Some units Pure Air services need attention every three to four months. For most residential heat pumps used year-round, once annually is the standard.
What’s it doing to your bill
Most homeowners clean the removable panels on the front of the unit. That’s the maintenance people know about. But that’s not the kind of maintenance that moves the needle on efficiency.
A professional deep clean means taking the unit apart, applying a mould-dissolving foam, and pressure washing the coils and blower wheel. When that blower wheel is heavy with buildup, the motor works harder to spin it. When the coils are clogged, the heat transfer suffers. Both problems run at the same time in a neglected machine.
The efficiency gap between a clean heat pump and a dirty one can reach 30 to 35 percent. On a monthly electricity bill, that gap is real and it’s recurring.
“Heading into the cold months, my heat pump was barely functioning and just couldn’t produce enough heat,” said Richard from Antigonish. Pure Air got him in quickly, did the deep clean and system reset, and the difference was immediate. “It was blowing hot air like it was brand new again.”
A heat pump is an investment. Installed, a new unit costs upward of $5,000. Most manufacturers require a professional deep clean every 12 to 18 months as a condition of the warranty. And not filter cleaning, but a full disassembly and wash. A machine running harder than it should, for longer than it should, loses operating life. Skipping a few hundred dollars in annual maintenance can move a major appliance replacement years closer than it needs to be.

What Pure Air does
The heat pump cleaning industry has a mixed reputation, built in part on early days when the work was done inconsistently by installers and tradespeople with varying levels of care. Pure Air has operated against that reputation since the company launched. Technicians arrive in uniform and marked vehicles, use drop sheets, and leave homes the way they found them. The company is fully insured, WCB covered, and holds an A+ rating with the Better Business Bureau.
“They laid down drop sheets, left the house absolutely spotless, and completely flushed out the system,” said Mike from Antigonish. “Our heat pumps look and run like brand new, and the air feels so fresh.”
Aimie from Havre Boucher has been booking Pure Air every year since her first service. “Pure Air Cleaning is incredibly professional, trustworthy, and a total pleasure to work with right from the very first phone call,” she said. “That’s why we have them back every single year.”
Pure Air also services commercial heat pumps, PTAC units in hotels and motels, and restaurant and industrial units that require more frequent attention. Dryer vent cleaning is available alongside heat pump service. Lint buildup in dryer vents is one of the leading causes of residential fires, and many insurance companies now require regular cleaning for coverage.
FAQ: What Homeowners Ask
How often should I have my heat pump professionally cleaned? Once a year covers most residential units. If the heat pump ran in cooling mode heavily over the summer, lean toward the shorter end of the manufacturer’s recommended window. Pure Air will tell you honestly if a unit doesn’t need work yet. If it’s clean, they say so and come back later.
Should I turn my heat pump off when I’m not home? Generally, no. Heat pumps are built to run continuously and are more efficient doing so. If you’re stepping out, turn the temperature down rather than the unit off. If you’re away for weeks or months, you can shut it down, but leaving it on low keeps the house dry and slows mould growth inside the unit.
Why do I get mould in my heat pump? Moisture from cooling and dehumidify modes settles inside the unit, primarily on the blower wheel, and mould follows. Using the heat pump in summer is the biggest driver. A unit used only for heating can often go longer between cleans, but mould still develops over time.
Does cleaning affect my warranty? Yes. Most manufacturers require a professional deep clean every 12 to 18 months as a warranty condition. Filter cleaning does not satisfy that requirement.
Should I clean my dryer vent at the same time? It’s worth considering. Lint buildup is a fire hazard, reduces dryer efficiency, and many insurers now require documented cleaning. Pure Air handles both in a single visit.
















