Check the ventilation fan is running

What to do

Find the switch marked VENTILATION FAN, and confirm the system it controls is actually running.

Why it matters

Every dwelling is required to have one and it is what keeps the humidity down. Turning it off in winter because it is cold or noisy is the commonest way an Alberta house starts growing mould at its windows — and the Habitat manual says in bold that damage from failing to ventilate is not covered by the warranty.

What to look for

• The switch is on, and has not been taped over, covered by a picture, or wired to something else
• Air is moving at the exhaust grilles — a tissue held up to one should hold
• The hood outside opens when it runs; a frozen or lint-jammed backdraft damper stops everything
• If it is an HRV: the condensate drain runs free and its trap has water in it
• It runs quietly enough that nobody in the house wants to switch it off, which is the real failure

Where this comes from

NBC(AE) 2023 9.32.3.1.(2) and 9.32.3.3. An HRV is one of three permitted ways to provide this, so a house with a continuously-rated bathroom fan instead is just as compliant and needs the same check. 9.32.3.12.(5) is the HRV condensate drain.