Trane Compressor lockout
I own a Trane 4TWX5048A (XL15i) Heat pump with electric auxiliary heats, all controlled with a Trane TCONT803 thermostat. This is my first winter with this unit and I’m having a problem with the compressor locking out when temperature goes below about 10F. Whenever this happens, I have to run of expensive electric heat until the temperature rises again above 10F, defeats the purpose of having an expensive heat pump, especially here in Alberta Canada.
I am looking for the cause of this “lockout”. I have set the thermostat for “no compressor lockout” or option “0” on installer setup number 0350. I am looking at resolving this problem, not sure if I’m overlooking something but would appreciate any suggestions.
I am not familier with the 803 stat, I ussually use the 802. I am going to say it is in the setup on the stat, the HO can only go so far with the settings they can change, if you are a tech then you know how to get to the other settings. But I guess the more important question is why, at 10* the heat pump is not that much more efficient than straight resistance heat. Yes it is more efficient but you won't save enough to make a big difference on your utility bill. Many dealers feel that running the pump when it is that cold out is hard on it and from my understanding it is harder on a compressor to run at 0 than at 100. As for me on resistance backup I don't shut it off because then it brings up the point of when is it warm enough to restart. I hope that helps.
Its not hard on a compressor to run at 0°F outdoor temp. The compression ratio is low at that temp, and doesn't stress the compressor as much as running it at 95° outdoor temp.
Most newer heat pumps will still be at a COP of 1.5 or better at 0°F.
So even with defrost, you'll still be saving 20%or more on your heating bill.
OP: Probably an improper installer set up.
Call your contractor and talk to him.
Thanks for the responses.
Based in similar systems in my area, I also believe the compressor should be running at well below 10F.
The contractor that installed my system is located more than 100 miles from my residence, this is why I am trying to fix the problem without having to call him to come all the way up here, especially if it's a simple fix through the thermostat set up that I could do myself. I will wait for further suggestions and if that doesn't work, I'll have to call him.
Since you have the stat's 350 set to 0.
You'll need your contractor to tell you why its locking out. may be another problem, other then the stat.
First winter? Should be under contractor 1 yr warranty then!!!
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Faulty freezestat? I ran into one of those on a packaged york unit. That or outdoor air sensor is probably opening above the setpoint. I don't know the unit so I couldn't tell you what kind of lockout mechanism it has. All depends. Call your tech or read the literature. It should be under warrantee.
Last edited by beenthere; 12-20-2009 at 07:20 PM.
Reason: Removed DIY diagnostics
Lets leave the diagnostics to the service tech. And not DIY.
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