A/C air is cold but weak flow
#1
05-30-18, 10:27 AM
A/C air is cold but weak flow
Moved into my house almost a year ago. AC unit is old.. 1995 Lennox C23-26-1 but worked fine last summer. This year not so much.. currently have thermostat set at 74° but AC can not even come close. The unit has ran for 3 days straight and fluctuates with the sun.. thermostat reading 75° in morning but was at 83° when I came home at 5pm yesterday. I go over by the vents and cold air is coming out but only like 3 inches above vent. Practically no air pressure coming out of the vents. Filter was a little dirty 3 days ago when I changed it. Still nothing different as far as temperature goes. Any ideas on what the problem could be?
#2
05-30-18, 11:13 AM
Member
If you have very little airflow coming out of the vents, the evaporator coil is likely frozen, blocking most of the airflow. A frozen evaporator coil is often caused by restricted airflow (dirty filter) or low refrigerant. I would suggest turning off the A/C and running just the fan. This should speed up the process of melting the ice. Once normal airflow returns, try running the A/C again. If it freezes up again (low airflow), you're likely low on refrigerant (you have a leak) and it's time to call an HVAC technician.
#3
05-30-18, 11:37 AM
Thank you for your help. How long does it usually take to thaw out the evap coil? When I changed the filter I had ice on larger of 2 pipes running from inside/outside unit(suction line?) I ran the fan with no cooling for 2 hours and the big line no longer had ice on it and still doesn't at this time. Would the evap coil take longer to thaw? Also I have been browsing the forums and I read the small thin line should be warm/semi hot to touch. Mine is like room temperature. I dunno if this information is useful.
#4
05-30-18, 11:43 AM
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Join Date: May 2008
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A lot of things can cause low airflow.
What tonnage is the A/C?
Larger tonnage tend to have poor airflow due to improper design...
What tonnage is the A/C?
Larger tonnage tend to have poor airflow due to improper design...
#5
05-30-18, 11:48 AM
Member
Originally Posted by Ecubed
Thank you for your help. How long does it usually take to thaw out the evap coil?
#6
05-30-18, 04:21 PM
Not sure where to look for the tonnage. As far as Bob's advice, I just got home turned cooling off and fan on. We will see results after 12 hours when I turn it on in the morning.
#7
05-30-18, 04:28 PM
Group Moderator
You can post the model number for the condenser and the air handler and we can look them up.
You posted a model number in your first post. That is a Lennox 2 ton coil/airhandler.
You posted a model number in your first post. That is a Lennox 2 ton coil/airhandler.
