Trane XL824 Thermostat

[Chuck in NC]

I replaced my heat pump a year ago with a Trane system.

Cooling and heating is good now (had some problems along the way) but one of the thermostats has started "drifting" and is not tracking actual temperature compared to a standard...sometimes as much as +/- 5 degrees.  I initially tried using the "calibrate" function but it does not help.  Unfortunately the temperature reading is just not repeatable.

Thermostat is a Trane XL824.  I am trying to get the system provider/installer to supply me with a replacement so that I can swap it out myself.

In the event they won't swap one with me I'd like to just buy a CHEAP thermostat and wire it in while I am trying to get a warranty replacement from Trane.

What do you recommend?

(IMHO the Trane transmitter is overpiced for the system in use..  Cost ~ $350.)

[Snipe Hunter]

I replaced my heat pump a year ago with a Trane system.

Cooling and heating is good now (had some problems along the way) but one of the thermostats has started "drifting" and is not tracking actual temperature compared to a standard...sometimes as much as +/- 5 degrees.  I initially tried using the "calibrate" function but it does not help.  Unfortunately the temperature reading is just not repeatable.

Thermostat is a Trane XL824.  I am trying to get the system provider/installer to supply me with a replacement so that I can swap it out myself.

In the event they won't swap one with me I'd like to just buy a CHEAP thermostat and wire it in while I am trying to get a warranty replacement from Trane.

What do you recommend?

(IMHO the Trane transmitter is overpiced for the system in use..  Cost ~ $350.)

Something Simple like an off the shelf Honeywell. But ping Blackhat first. <- Always a good idea around here.

[Roly]

I replaced my heat pump a year ago with a Trane system.

Cooling and heating is good now (had some problems along the way) but one of the thermostats has started "drifting" and is not tracking actual temperature compared to a standard...sometimes as much as +/- 5 degrees.  I initially tried using the "calibrate" function but it does not help.  Unfortunately the temperature reading is just not repeatable.

Thermostat is a Trane XL824.  I am trying to get the system provider/installer to supply me with a replacement so that I can swap it out myself.

In the event they won't swap one with me I'd like to just buy a CHEAP thermostat and wire it in while I am trying to get a warranty replacement from Trane.

What do you recommend?

(IMHO the Trane transmitter is overpiced for the system in use..  Cost ~ $350.)

Did you sign up with your utility for a discount if they can control the temperature during high use periods.   Most people dont read what they are signing up for and it is a surprise when they take over the temp control.     Bet this is the issue .   Roly

[blackhat]

I am not a fan of this trend in home HVAC. So many things can go wrong. Interference in wireless connection. Interference in wired connections. Source power issues like harmonics in your AC power supply. On and on and on. 

To answer your question about a replacement thermostat, it will depend on your air handler and heat pump    Checking the install manual for that should help one figure out what’s needed to replace the existing.

[Chuck in NC]

Did you sign up with your utility for a discount if they can control the temperature during high use periods.   Most people dont read what they are signing up for and it is a surprise when they take over the temp control.     Bet this is the issue .   Roly

Roly, I don’t have an agreement with the utility.  My thermostats (2 upstairs zones and 1 downstairs zone) are standalone, not available via Wi-Fi, etc.  Upstairs zones work great. Problem is downstairs zone thermostat only.

One of the upstairs zones is still running on the OLD Honeywell thermostat from previous heat pump.  It is 16 years old.

[brnhornt]

Interesting timing.  I got a new Trane furnace/ac last fall.  This is our first cooling season.  Fall and Winter were fine, but now I notice the unit short cycling.  AC will run for around 3 minutes at a time.  If I manually change the setpoint to say 82, and let the house warm up during the day to say 79, when I change the set point back to 73....it will run fine for say an hour to bring the house down.  So I know it's not like there is a error in the unit itself that causes it to only run for three minutes at a time.  It's simply the thermostat calling for cooling too soon.  I tried, and can't find anywhere I can tell the thermo to let the house temp drift up by 2 or 3 degrees before calling for cooling.  It's like it has a mind of its own and simply has to keep the temp at 73 no matter what.  Very disappointed with this thing.  Also frustrated by the fact that Trane won't offer support on the thermostat.  They keep telling me to call my installer.

[Roly]

Interesting timing.  I got a new Trane furnace/ac last fall.  This is our first cooling season.  Fall and Winter were fine, but now I notice the unit short cycling.  AC will run for around 3 minutes at a time.  If I manually change the setpoint to say 82, and let the house warm up during the day to say 79, when I change the set point back to 73....it will run fine for say an hour to bring the house down.  So I know it's not like there is a error in the unit itself that causes it to only run for three minutes at a time.  It's simply the thermostat calling for cooling too soon.  I tried, and can't find anywhere I can tell the thermo to let the house temp drift up by 2 or 3 degrees before calling for cooling.  It's like it has a mind of its own and simply has to keep the temp at 73 no matter what.  Very disappointed with this thing.  Also frustrated by the fact that Trane won't offer support on the thermostat.  They keep telling me to call my installer.

Try setting the heat in heat mode to come on at say 70 degrees and set the cooling in cooling mode to come on at say 74 degrees.   That will be the differential (4 degrees) then set to system auto.  This is how mine works.     Dont set the differential too close as it will short cycle as yours is doing.   Google the model # of thermostat for manuals.   Did you call your installer ?   Roly

[brnhornt]

I did call the installer.  Their tech said that modern AC systems like what I had installed aren't affected by short cycling, so it will be ok as long as the unit is in fact cooling and the house remains at the set point.  I'm fighting back and forth in email with Trane's customer support trying to get someone to give me a manufacturer's opinion on if the tech is correct or not.  They keep wanting to shuffle me off to the installer.

I do have the manual...but will say, I haven't tried using the Auto setting, so I'll have to go take a look at that.  Thank you.  I more of a when I want AC, I set it to Cool, if I want the furnace, I set it to Heat.

[Chuck in NC]

Interesting timing.  I got a new Trane furnace/ac last fall.  This is our first cooling season.  Fall and Winter were fine, but now I notice the unit short cycling.  AC will run for around 3 minutes at a time.  If I manually change the setpoint to say 82, and let the house warm up during the day to say 79, when I change the set point back to 73....it will run fine for say an hour to bring the house down.  So I know it's not like there is a error in the unit itself that causes it to only run for three minutes at a time.  It's simply the thermostat calling for cooling too soon.  I tried, and can't find anywhere I can tell the thermo to let the house temp drift up by 2 or 3 degrees before calling for cooling.  It's like it has a mind of its own and simply has to keep the temp at 73 no matter what.  Very disappointed with this thing.  Also frustrated by the fact that Trane won't offer support on the thermostat.  They keep telling me to call my installer.

I did call the installer.  Their tech said that modern AC systems like what I had installed aren't affected by short cycling, so it will be ok as long as the unit is in fact cooling and the house remains at the set point.  I'm fighting back and forth in email with Trane's customer support trying to get someone to give me a manufacturer's opinion on if the tech is correct or not.  They keep wanting to shuffle me off to the installer.

I do have the manual...but will say, I haven't tried using the Auto setting, so I'll have to go take a look at that.  Thank you.  I more of a when I want AC, I set it to Cool, if I want the furnace, I set it to Heat.

(Temperatures in Degrees F).

I have 2 Trane XL824 thermostats.  Upstairs works as expected.  Downstairs thermostat temperature display readings drift over time.

I don't have a concern with a 1 degree setpoint deadband.  My Trane heat pump turns on when the XL824 thermostat temperature is 1 degree above the cooling setpoint.  When the temperature falls to 1 degree below setpoint the cooling shuts off.

My heating setpoint is 10 degrees below the cooling setpoint, so I don't have a situation where the unit is cycling between "Cooling" and "Heating".

My complaint is that the temperature reading on the downstairs Trane XL824 display does not always track the actual temperature.  

I have placed a standalone digital temperature transmitter and an old Bryant thermostat next to the downstairs Trane thermostat.  The Bryant and digital temperature displays track each other within 1 degree no matter what setpoint is used.  The Trane thermostat reading drifts by several degrees over time.

My Trane provider is sending a tech to "troubleshoot and replace as needed".  I told the service manager that the defective thermostat needs to be replaced.  If they won't do it then I will buy a $20 thermostat and install and set up myself.

The provider has been out to my house at least 7 times in the past year for warranty support.  Good grief!

[Cabinet Monkey]

I replaced my heat pump a year ago with a Trane system.

Cooling and heating is good now (had some problems along the way) but one of the thermostats has started "drifting" and is not tracking actual temperature compared to a standard...sometimes as much as +/- 5 degrees.  I initially tried using the "calibrate" function but it does not help.  Unfortunately the temperature reading is just not repeatable.

Thermostat is a Trane XL824.  I am trying to get the system provider/installer to supply me with a replacement so that I can swap it out myself.

In the event they won't swap one with me I'd like to just buy a CHEAP thermostat and wire it in while I am trying to get a warranty replacement from Trane.

What do you recommend?

(IMHO the Trane transmitter is overpiced for the system in use..  Cost ~ $350.)

(Temperatures in Degrees F).

I have 2 Trane XL824 thermostats.  Upstairs works as expected.  Downstairs thermostat temperature display readings drift over time.

I don't have a concern with a 1 degree setpoint deadband.  My Trane heat pump turns on when the XL824 thermostat temperature is 1 degree above the cooling setpoint.  When the temperature falls to 1 degree below setpoint the cooling shuts off.

My heating setpoint is 10 degrees below the cooling setpoint, so I don't have a situation where the unit is cycling between "Cooling" and "Heating".

My complaint is that the temperature reading on the downstairs Trane XL824 display does not always track the actual temperature.  

I have placed a standalone digital temperature transmitter and an old Bryant thermostat next to the downstairs Trane thermostat.  The Bryant and digital temperature displays track each other within 1 degree no matter what setpoint is used.  The Trane thermostat reading drifts by several degrees over time.

My Trane provider is sending a tech to "troubleshoot and replace as needed".  I told the service manager that the defective thermostat needs to be replaced.  If they won't do it then I will buy a $20 thermostat and install and set up myself.

The provider has been out to my house at least 7 times in the past year for warranty support.  Good grief!

Think it’s time you look for a new installer / servicer.