Why Are Some Rooms Cold When My Furnace Runs?

Published: July 23, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC

Simple Fixes First

Check: all supply registers are fully open and not blocked by furniture, return air grilles are unobstructed, furnace filter is clean (dirty filters reduce airflow to distant rooms), and interior doors are open to allow air circulation.

Duct Balancing

Partially close the dampers or registers on the warmest rooms to push more airflow to cold rooms. Many homes have manual balancing dampers on the ductwork near the furnace. Adjust in small increments and wait 24 hours between adjustments.

Professional Solutions

If simple fixes do not resolve cold spots, consider: duct sealing (leaky ducts lose air before reaching rooms), added insulation in problem rooms, zone control dampers ($1,500-3,500), or a ductwork redesign for severely imbalanced systems.

Related Services

Safety Reminder

If you smell gas, suspect carbon monoxide or believe there is an immediate danger, leave the property and contact emergency services or the appropriate gas emergency authority. Do not remain inside — exit the building immediately and call for help from outside.