From reading in this forum that sometimes the installing technicians are not always prone to perfection and after four seasons of cooling and heating, I decided last week to check my dipswitch setting for the first time on my Trane XV90 furnace/air handler. Based on the information in my Trane XV90 Installer’s Guide, page 12, Service Facts, the settings appear to be wrongly set and since I plan to call for my semi-annual maintenance check for the cooling season, I invite you pros to give me some input about my settings so the technician can address my dipswitch settings if indeed they need to be adjusted.
My system is used to cool/heat a 2350 sf single story house in Marietta, Georgia with horizontal furnace and ductwork in attic that consists of the following units:
Trane Gas Furnace XV90/Air Handler UY100R9V4 (100BTU)
Trane XL14i Compressor Model No. 4TTX4048A1000AA (4 ton)
Trane Evaporator Coil Model No. RXC054S3HPCO
Honeywell Thermostat VisionPro TH8320
Below is a visual of my current dipswitch settings and based on the information given in the Installer’s Guide, Service Facts, pg. 12, it appears to me that dipswitch numbers 1, 4, 7 & 8 are not correct. The current settings of switches 1, 2, 3 & 4 appear to be set for the “low” air flow setting for a 3.5 ton condenser (mine is 4 ton) and switches 7&8, for heating, appear to be set for “medium low” air flow setting and need to be set exactly opposite of how they are now set.
Last summer during the repair of a refrigerant leak situation, I recall the technician telling me that switches 5&6 were not correct for Comfort-R to work effectively and he changed them at the time and they appear to be set correctly. Also, I remember the same technician telling me the sub-cooling temperature should read between 9 & 13 degrees and he deemed my system ready for service at 11 degrees sub-cooling. One thing I wonder about is if dipswitches 1 through 4 are changed to the factory “medium” settings for 4 tons (all 4 dipswitches off) with increased airflow through the evaporator coil (457 CFM difference from the current setting at 0.1 external static pressure), how will this affect the sub-cooling degree readings? And, will this increased air volume change likely require any addition or removal of refrigerant as, from a homeowner’s understanding, the gas line temperature would be raised by the increased air volume over the coil and would change the sub-cooling temperature readings at the outside unit?
I recall reading a post by Baldloonie about setting the airflow setting to 350 CFM/TON to improve comfort in high humidity situations during the cooling season and maybe this is why some of my dip switch setting are set at other than medium/factory settings. The heat settings, I just don’t know?
Any thoughts, suggestions or comments are appreciated.