When Your Furnace Refuses to Start Below Zero
April 2, 2014
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Many furnace owners say their furnaces refuse to start under really cold weather. This is attributed to the lack of heat the combustion process needs to fire up the furnace. The topic has been the focus of several discussions on online forums, in addition to piquing the interest of HVAC contractors and experts.
If this is the case, then you shouldn’t be looking at the furnace. The problem can be fixed if you check the fresh air intake instead, which is often mounted on the sidewall. It appears that the air coming into the furnace is just too cold to initiate combustion. Some owners manage to resolve the issue by placing their hand over the intake.
However, contractors can’t help but ask whether or not this is an abnormal issue. Furnaces, in general, seldom work with the amount of heat loss in the house. If the amount of heat loss isn’t equal or less than the heat load the furnace is designed to take, the furnace may switch on and off consistently and frequently.
Whether or not the hand-over-intake trick really works, a furnace that refuses to start in subzero weather can, at least, be attributed to heat loss. Without sufficient heat inside the house, the furnace can’t commence the combustion process. This is why furnace installation and insulation come hand in hand.