Know your supply vents from your return grilles
Your heating system moves air in a loop. Supply vents blow warm air into the rooms. Return grilles pull air back to the furnace or air handler to be heated again. Returns are usually bigger, often on a wall or ceiling in a hallway, and many of them hold the air filter.
Both sides of that loop matter. If the system cannot pull enough air back through the returns, it cannot push enough warm air out through the supply vents.
Walk the house with the heat running and hold your hand near each vent. A supply vent with weak airflow is worth noting before you call.
Source: ENERGY STAR — Duct Sealing
Move the furniture, rugs and curtains
Look for anything sitting on top of a floor register or right in front of a wall vent: sofas, beds, dressers, area rugs, long curtains and stacks of holiday boxes. Pull them back so the air has a clear path into the room. Keep returns open too. A return grille behind a dresser or under a bed is one of the most common things I find.
Do not close a bunch of supply vents to push heat into other rooms or to save money. Closing too many can make the system strain and can make some rooms colder, not warmer.
Vacuum the vent covers and return grilles while you are at it. Dust on the grille is usually a sign the filter behind it is due too.
Change the filter and know when to call
A clogged filter does the same thing as a blocked return. If your filter sits behind a return grille, check it now and change it if it is gray. Match the size printed on the old filter, and point the arrow toward the furnace or air handler.
If the vents and filter are clear and one room is still cold, a duct may be loose, crushed or disconnected in the attic or crawlspace. That is a job for me, not something to fix in the attic yourself. A burning smell or no airflow at all means turn the system off at the thermostat and call.
One room cold even with clear vents? Call me at (470) 999-7395. A $79 diagnostic is how I find out whether it is the ductwork or the system.
