Cleaning your heat pump filters and unit: why it pays to do it often

Clean filters are the simplest maintenance step for your wall-mounted heat pump, and the one that pays off the most. And every so often, the unit itself needs a real cleaning by a technician. Here is why, how often, and who does what.

Why keep the filters clean

The filters in the indoor unit catch dust, pet hair and pollen before the air reaches the coil. When they clog, air flows less freely, and everything else suffers.

• Comfort: less warm (or cool) air comes out, and rooms take longer to reach the temperature you set.
• Efficiency and energy bills: to deliver the same comfort, the unit has to run longer and harder, so it uses more energy.
• Compressor life: a system that is always straining wears out its parts faster, including the compressor, the most expensive part of a heat pump.
• Air quality: a clogged filter holds dust and allergens less well, and the dirt ends up deeper in the unit, where it can cause odours.
• Noise: when air can't get through, the fan works harder and the unit can get louder.
• Freezing and water leaks: in cooling mode, too little airflow can freeze the indoor coil; when the ice melts, water can overflow and drip from the indoor unit. In heating mode, the unit can overheat, lower its output or even shut itself off for protection.

Another reason not to wait: when too much dust builds up on the filters, it starts building up on the indoor coil, which leads to a more expensive deep clean, as the New Brunswick Energy Efficiency Programs maintenance guide points out.

How often should you clean the filters?

The right frequency depends on your unit, your home and how much you use the system. A good rule of thumb:

• In general: check or clean the filters every 3 to 4 months, following the manufacturer's recommendations.
• More often if you have pets, are doing renovations (drywall dust clogs filters fast), someone in the home has allergies, or you also heat with wood.

If your filters look grey or dusty before then, clean them right away. And your unit's manual always has the final word: follow the frequency recommended for your model.

How to clean the filters yourself

1. Turn the unit off with the remote.
2. Lift the front panel of the indoor unit and gently slide out the filters.
3. Vacuum them with a soft brush, or rinse them in lukewarm water. Avoid hot water and harsh cleaners unless the manual allows them.
4. Let them dry completely, out of direct sun.
5. Put the filters back, close the panel and turn the unit back on.

Never run the unit without its filters: dust would go straight onto the coil. For a central (ducted) system, the disposable filter can't be washed: replace it with one of the same size, as the manufacturer recommends.

Cleaning the filters vs. cleaning the unit: what's the difference?

Anyone can clean the filters in a few minutes. But even with clean filters, some dust gets through and builds up deeper in the unit. Deep-cleaning the unit is a job for a technician:

• The indoor coil (evaporator): the thin fins where the air is heated or cooled. When it's dirty, it transfers heat less well.
• The blower wheel (turbine): dust, and sometimes mould, sticks to it. It then blows less air, can get noisy and give off odours.
• The condensate pan and drain: if they clog, water can drip from the indoor unit.
• The outdoor unit: cleaning the coil and fins, and making sure nothing blocks the airflow.

This work means partly taking the unit apart, protecting the electronic components and using the right products and equipment. The fins bend easily and electronics don't like water: it's best left to a technician.

How often should the unit be deep-cleaned?

As a general guide, for a full cleaning of the unit (coil, blower wheel, drain):

• every 3 to 4 years in a home with little dust;
• every 1 to 2 years with pets or kids;
• every year in a very dusty home.

The filters, for their part, should be checked or cleaned every 3 to 4 months, following the manufacturer's recommendations.

Signs it's time to have the unit cleaned

• less heating or cooling than before, even with clean filters;
• a fan that's louder than before;
• odours when the unit starts;
• visible dust or black spots on the blower wheel or at the air outlet;
• water dripping from the indoor unit;
• small bits of debris blown out of the unit.

Manufacturers require regular maintenance. A subscription is not required to keep your warranty, but with our plans, every visit is recorded in a written report.

Questions, or need a one-time maintenance visit? Request a quote or call us at 418 956-4455.

Sources

• New Brunswick Energy Efficiency Programs (NB Power), Maintaining Your Heat Pump.
• U.S. Department of Energy, Building America Solution Center, Clean Ductless Heat Pump Air Filters.