Lots of issues with our Trane system

Old 07-17-17, 07:16 PM
Thread Starter
Join Date: Jul 2017
Location: USA
Posts: 1
Received 0 Votes on 0 Posts
Lots of issues with our Trane system

We have had a 2 stage Trane for 6 years. Last year we learned that the second stage had never been connected. The original contractor returned and fixed this problem. We have had numerous other issues with ducts leaking air, etc. Everything seemed to be fixed but as the temperature climbed a couple of weeks ago, we weren't feeling the cooling that we should have. Checked all vents and cool air is coming out but not very forcefully. I called the contractor again and his guy now says that the coil needs replacing because it is constricted - how does that happen? We have service every 6 months so there is no dirt on the coil. When I google for coil problems I see either dirt or bushes growing into the system. We have neither issue. What could cause the coil to go bad at only 6 years? If the coil is bad, why do we feel cool air coming out of the vents? I asked him and he said it feels cool because it is cooler than body temp but I know this is cooler than other air and would be hot coming out of attic ducts if there was no cooling. He said it is partially constricted. Anyone ever heard of this? Thank you.
Old 07-17-17, 07:25 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,543
Received 1,599 Votes on 1,473 Posts
Welcome to the forums.

If you don't feel a forceful airflow then you have an airflow problem.

Restricted coil can mean two things...
1) it's clogged with dust.
2) it has a refrigerant problem like a possible TXV problem. The TXV is what controls the flow of refrigerant thru the coil.

You said the coil is clean..... how do you know ?
You need to look at the side of the coil where the air enters.... the return side.
Is there a filter and has it been replaced ?
Old 07-18-17, 03:49 AM
Bob14525's Avatar
Join Date: Jun 2013
Location: USA
Posts: 1,630
Received 30 Votes on 25 Posts
One quick way to tell if the evaporator coil is freezing up and limiting airflow is to leave the A/C off for 5-6 hours but leave the fan (blower) on (change thermostat switch from Auto to On). This will melt any ice that may have formed on the evaporator coil. After the "de-icing" period is over, turn the A/C on (set thermostat to call for cooling) and feel the airflow. If the airflow now feels "normal", you likely have an icing problem, usually caused by the system being low on refrigerant. If the airflow is still weak, then you may have a dirty evaporator coil or something else that's restricting the airflow.
Old 07-18-17, 04:15 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
Did they add refrigerant when they added second stage operation? Did they list the actual amp draw for the two different compressor speeds?

If that model has the charge assist LED's, the 3 toggle options of short, medium and long line set needs to be set to match the line set (Usually medium when you factor 90's and lift) if they used this function.

The refrigerant charge would look different in high speed than low speed. I wonder if this could have caused confusion.
Old 07-18-17, 05:44 AM
Join Date: Jul 2017
Location: US
Posts: 3
Received 0 Votes on 0 Posts
A quick and easy way to check for air restriction at the air handler would be to check the pessure drop across the coil. They can also check static pressure.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: