I have just spent the past four or five hours reading and searching this forum and the internet for a problem similar to mine, but could not find one, so here it is:
We are having another issue with our new Trane 3 ton XL 20 i, TAM 8 air handler, all new duct work, and XL950 Comfortlink II thermostat installed March, 2012. We are located in the Tampa, Fl area, slab floor, single story, air handler in the attic, duct board plenums, flex duct work for intakes and supplies.
The newest problem started a few weeks ago as the weather started to cool off and the AC was not used very often.
We have lived in this house for about 25 years and had the original GE system, replaced by a Trane system, replaced by this Trane and never had any issues with musty odor until now.
Here is the scenario:
Cooler outdoor temps result in less AC run time and at slower fan speed
AC turns off and does not turn back on for hours or days
When AC turns on, musty odor is easily detected throughout the house
If AC and fan run on higher speeds for an hour or more, odor goes away
AC runs on lower fan speed, odor is back
If heat is used, odor goes away after a few minutes and does not return until low speed AC is used again.
Here is what dealer has done:
Made sure water is draining properly
Although filter media was clean, replaced 4 thick pleated filter media on air handler return
Installed new, updated doors on the air handler as originals were leaking
Inspected coil for dirt, mold, etc
Cleaned coils even though there was no visible evidence of dirt or mold
Spayed Dirty Sox on coil
Odor was gone for about three days, and then came back, although not as strong as before dealer did his thing.
But, odor is back. I am starting to get very frustrated with this system due to all the issues that are related to this expensive Trane system. Slowly, the dealer has been able to work with Trane to partially resolve some of the problems, but for most issues Trane says nothing, or it is a design issue and will not be fixed until the next generation and we will have to buy it to fix our problems.
Because of the problems we have had, and Tranes position on them, I am tending to think this musty odor is another Trane design issue, but dont know for sure. Dealer says they have had to replace a few coils due to various issues not related to odor, and I am starting to wonder if this is a coil material issue.
Anyway, does anyone have any suggestions on what can be done to fix this odor issue (short of replacing the system with another brand)?
Why the odor issue now after 25 years of no problem until this new system?
Has anyone seen this problem on other TAM 8 systems?
Entire system is new ducting, plenums, everything except a couple of air vents even new and additional air returns.
thank you all for your valuable input.