If you only do one thing for your heat pump this year, make it this: pop the front cover, slide out the mesh filters, rinse them under the tap, let them dry, and put them back. It takes two minutes, and it does more for airflow than anything else you can do at home.

The question we get from homeowners is always the same one: how often is "often enough"?

The honest answer

Manufacturers will tell you "every two weeks." That's the conservative, cover-our-backs number. Here's what we actually see in Nova Scotia homes:

  • Every 4–6 weeks if the unit runs daily (heating in winter, cooling on humid summer days)
  • Every 2–3 weeks if you have shedding pets, allergies, or run the unit hard in a small space
  • Once a season if it's a second-floor head you barely use

The right answer is the one that matches how dusty your filter actually looks when you check it. After a few months you'll know your home's rhythm.

How to know you're overdue

Three signs, in order of how quickly they show up:

  1. The airflow feels weaker. Same fan setting, less air coming out of the louvres.
  2. The unit cycles more often. A clogged filter makes the heat pump work harder, which makes it run longer.
  3. A faint stale smell. Not the heavy musty smell — that's a different problem — but a dusty, attic-ish note when the unit kicks on.

How to actually do it

If you've never opened your indoor unit, here's the full process. It's easier than it looks.

  1. Turn the unit off at the remote. Wait 30 seconds.
  2. Lift the front cover. Most units pivot up on hinges at the top — gently. It'll click and hold open on its own.
  3. You'll see two mesh filters, one on each side. They slide up and out of their tracks.
  4. Rinse them under the tap, warm water, both sides. No soap needed. If they're greasy from kitchen vapour, a tiny drop of dish soap is fine.
  5. Tap them dry on the edge of the sink. Lay flat on a towel for 20 minutes — putting them back wet is what causes that musty smell people blame on their unit.
  6. Slide them back into their tracks. Close the cover until it clicks.

That's it. The whole job is two minutes plus drying time.

When rinsing isn't enough

Mesh filters catch the big stuff — dust, hair, lint. They don't touch the coil, the blower wheel, or the drain pan. If your unit smells musty after a clean filter is back in, or if it hasn't had a proper wash in 12+ months, that's what a BlueBear cleaning is for. Filters keep you between visits; we handle everything behind them.

One more thing

Don't run the unit with the filters out. We've seen homeowners do this thinking they'll get better airflow before a guest arrives. What actually happens is the dust your filter would have caught lands directly on the coil — where it costs a service call to remove instead of a tap rinse.

Put the filters back, even if they're a little damp. Cleaner airflow comes from a clean filter, not no filter.