Hi All,
Our a coil in the air handling unit freezes up completely. It happenend after 6 days of running without a problem then it happened twice in a day. The same thing happened last season. Duct work is clean, filter is new.
Please tell me if anyones had this experience and their cure.
Thanks,
Charlie
Replies
If the air flow is good then the most likely cause of the problem is low freon.
What Bill said. Same thing happned to us a couple of years ago. Found a leak, unfortunately it was at the connection to the condenser and was almost as costly to repair as to replace.
Low freon..
dirty coil(s)...
defrost timer or sensor...
when was the last time you washed the condenser out?
does the drain, drain.
have you made sure evaporator has all the baffles in place so the air has to go though the evaporator coils in the furnace not around them.
Fred, a dirty condenser coil generally causes a unit to trip on the high head pressure switch.
Restrictions in air flow across the evaporator and a low charge are the general cause of evap. coil freezing.
Funny though that you mention the dirty condenser coil problem. I finf it humorous that some people will wash thier car once a week and think it runs better, but never wash the a/c condenser coil and wonder why it doesn't work as well as it use too.
Dave
CAUTION before checking this turn off the power to the blower fan so not to get your fingers in the belt. If the fan belt on the blower is slipping you will have a reduced flow of air over the evaporator coil, it usually squeaks if slips but not always. If you find the blower fan it self is dirty, that will cut the volume of air it moves.
If it is not any of that you need AC man to have a look.
Yep, low air flow (clogged filter or fan set to low speed) or low on freon.
When things are marginal it will depend on temperature/humidity whether it happens or not, but once it starts the ice lowers airflow further and it (ahem) "snowballs".