Heat pump blowing cold air in heating mode
Before you worry: a heat pump that blows cool for a few minutes now and then is often doing exactly what it should — melting frost off the outdoor coil.
In Canadian winters, watch the timing first. If the cool air lasts only a few minutes and warm heat returns on its own — often with a whoosh and some steam off the outdoor unit — that's a normal defrost cycle, not a breakdown. Note how long it truly stays cold before assuming a fault.
Causes probables, dans l’ordre à vérifier
Ordre typique affichéhandymanHow to fix it
Find the filter at the indoor air handler or return grille, note the size printed on its frame, and slide in a fresh one facing the airflow arrow the right way.
- Locate the filter slot on the indoor air handler or the large return-air grille.
- Slide out the old filter and read the size stamped on its cardboard frame.
- Insert a matching new filter with the printed airflow arrow pointing toward the unit, and set a reminder to check it monthly in heating season.
Replacing a return-air filter is routine homeowner maintenance in every province.
verifiedPourquoi confier ceci à un pro
The reversing valve and refrigerant charge are part of the sealed system. In Canada, working with refrigerant requires certification, and valve replacement means brazing on pressurized lines. This is a licensed HVAC repair — a technician can confirm it quickly.
Vos notes accompagnent la demande — ce que vous avez vu, ce que vous avez éliminé, quand ça a commencé — pour que le pro arrive avec une longueur d’avance.
visibilityHow to check
- Go outside and look at the whole outdoor unit — light frost is normal in winter, but a solid coat of ice over the coil or snow drifted against the sides is not.
- Clear snow away from the sides and top by hand or with a soft brush so air can move through the coil.
- Let the unit run through a defrost cycle. If it clears and stays clear, you're done; if it glazes over again quickly, the defrost controls need a technician.
verifiedPourquoi confier ceci à un pro
The reversing valve and refrigerant charge are part of the sealed system. In Canada, working with refrigerant requires certification, and valve replacement means brazing on pressurized lines. This is a licensed HVAC repair — a technician can confirm it quickly.
Vos notes accompagnent la demande — ce que vous avez vu, ce que vous avez éliminé, quand ça a commencé — pour que le pro arrive avec une longueur d’avance.
Pourquoi la liste est dans cet ordre
Nous ne classons pas seulement selon la probabilité. Nous classons comme le ferait un bon artisan honnête : éliminer d’abord les causes gratuites, sûres et courantes. C’est pourquoi les vérifications peu coûteuses passent avant les réparations chères — et pourquoi tout ce qui est dangereux reçoit un arrêt net plutôt qu’un encouragement. Cet ordre existe pour vous faire économiser, pas pour vous vendre quelque chose.