Trane XL950 not reading indoor temp correctly and shows error 126

[Silverspur]

It has been a while since I last posted and I wanted to provide all with an update to my issues.

The installer was finally able to get some information out of the local Trane field person and this is what has transpired.

The second XL950 thermostat was reinstalled with V2 software and the entire system was (thermostat and air handler) powered down and then a factory reset was done on the air handler and the thermostat. Lo and behold all parts now communicate - no error 126!! yeah!! The system works again. We did have to reprogram everything in the thermostat and air handler, and lost all the history.

Next, the thermostat was re-located to be directly, and I mean directly beneath the main air return. The reason for this is in the summer heat, the XL950 would show the room temperature to be in the mid 80's when the room was acutally in the mid 70's. This would cause the system to run and never shut down. Nothing would solve this - recalibartion cannot compensate for this big a difference, spacing the thermostat off the wall three inches did not help, nothing seemed to solve the problem, and it read incorrectly only in when the system was on and when it was very hot outside.

The installer was informed by the Trane rep that there is a design issue with the XL950, and it is known by Trane that the thermostat will read erroneously by a substantial amount due to self heating. The electronics in the t-stat heat up and cause the ambient room temperature sensor to read high from the internal heating. I actually measured the back of the XL950 to be as much as 115 F with an infra-red thermostat. It is hot to the touch.

Anyway, the Trane rep says Trane knows about this and says to mount the XL950 directly in the return airflow so the ambient room sensor has room air moving over it at a good volume. When the installer asked the Trane rep when a fix would be available for this, the rep suggested there would be no fix until the next model came out, and the home owner would have to purchase a new one.

So, Trane has a design problem and I am stuck with an expensive thermostat that does not work properly, and Trane says I have to purchase a new one if and when they come out with a new model... Thank you Trane, nothing like customer service and standing behind your product. It only took about four months to get this information out of them by the installer.

Well, at least I have a working system with the thermostat in a location that is not desireable for me, and I have some nice holes in my wall from the old location. I have since seen the Carrier version of this and think I might go with Carrier next time.

[tkcc123]

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[jpsmith1cm]

tkcc123
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[jimj]

Next, the thermostat was re-located to be directly, and I mean directly beneath the main air return. The reason for this is in the summer heat, the XL950 would show the room temperature to be in the mid 80's when the room was acutally in the mid 70's. This would cause the system to run and never shut down. Nothing would solve this - recalibartion cannot compensate for this big a difference, spacing the thermostat off the wall three inches did not help, nothing seemed to solve the problem, and it read incorrectly only in when the system was on and when it was very hot outside.

The installer was informed by the Trane rep that there is a design issue with the XL950, and it is known by Trane that the thermostat will read erroneously by a substantial amount due to self heating. The electronics in the t-stat heat up and cause the ambient room temperature sensor to read high from the internal heating. I actually measured the back of the XL950 to be as much as 115 F with an infra-red thermostat. It is hot to the touch.

Anyway, the Trane rep says Trane knows about this and says to mount the XL950 directly in the return airflow so the ambient room sensor has room air moving over it at a good volume. When the installer asked the Trane rep when a fix would be available for this, the rep suggested there would be no fix until the next model came out, and the home owner would have to purchase a new one.

So, Trane has a design problem and I am stuck with an expensive thermostat that does not work properly, and Trane says I have to purchase a new one if and when they come out with a new model... Thank you Trane, nothing like customer service and standing behind your product. It only took about four months to get this information out of them by the installer.

.

The fix for your problem is to mount a remote sensor directly below the 9500. This will now give you accurate temp reading at the stat. I'm suprised the FSR is not aware of this fix.

[Silverspur]

jimj, when a remote sensor was added way back at the begining of this, I lost humidy control. When the sensor was removed, they had to do a factory reset on the XL950 as it would not "forget" that the remote was no longer connected and the system errored and would not work.

Still, even if humidity control did work, adding a remote sensor seems to me to be a band aid, not a fix. I am an engineer, and at companies I have worked for, this would be totally unacceptable for more than a temporary fix. The XL950 has a design problem as does the TAM air handler, Trane knows of these issues and will not fix them properly and replace what I paid a lot of money for.

I have used Trane products for about 20 years purchasing at least four units over the years for various buildings, but after this experience with poor Trane support and known design issues that Trane will not fix, I think I am about finished with Trane and will try a different brand next time.

I like the ideas Trane attempted to implement, but do not like the way they did the implementation and their lack of respect for the customer essentially saying your bought it, now it is your problem and if you want it fixed, you have to buy the next revision.