Why Does My Outdoor Unit Sometimes Have Ice Buildup During The Winter?

Under certain weather conditions, the outdoor unit will develop ice buildup. When the unit defrosts this ice, it gives off water vapor, which appears to be smoke. If excess ice builds up on the outdoor unit after more than 90 minutes elapsed time, switch emergency heat to "on" and call your heating and cooling contractor if the condition does not clear.

Should The Outdoor Unit Run Continuously?

Below the balance point, around 30 ° F it is normal for the outdoor fan to continually run. If the outdoor unit continually runs during normal heating (30 °-50 ° F outside), possible problems are:

• Thermostat set too high
• Thermostat needs adjustment
• Low refrigerant level in unit
• Thermostat exposed to cold draft
• Outside unit coil is blocked by snow, ice, etc.

If the outdoor unit continually runs during normal cooling, possible problems are:

• Low refrigerant level in unit
• Very warm weather (over 90 ° F)
• Thermostat located near heat source, such as appliances, TV, etc.
• Dirty filters or too many registers closed limiting air movement
• Improperly designed duct work
• Unit may be undersized