Dan O. -- Friday, 28 July 2000, at 12:58 a.m.
: I have a 8500 btu window air conditioner. It is
: probably at least 10-15 years old, and had
: worked like a dream. This evening I came
: home and found no air coming from the vent
: and the evaporator coil is frozen. I turned
: it off. What could have caused this?
If the coil was totally frosted over and not just partially, the problem could have been that the air flow through the unit was hampered.
If the inside or outside air temperature drops much below 70° F, the moisture recovered from the room air freezes on the evaporator coil, instead of just condensing there. This severely restricts air flow.
The other common causes are when the filter gets plugged. Also if the blower fan breaks or gets too dirty or the motor fails totally, the same symptom can result.
Curtains or other objects can obstruct the air flow causing the cold air to be drawn right back into the unit. This causes the expelled air to get colder and colder unit the frost forms. These obstructions can also cause no air to circulate through the evaporator with the same end result.
: Is it serious or will it be ok after the
: coil thaws?
When an air conditioner is left in this condition for any length of time, the fan motor can burn out. If the fan was running when you got home, it will probably be OK. If it won't blow after it thaws completely, it probably needs replacing.
See the link below for some helpful A/C tips.
Dan O.
