Heat Pumps and Electric Heating - Trane XL1400 low heat temp output!
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : Trane XL1400 low heat temp output!
paschal
10-20-09, 10:40 AM
This is total electric home. Unit has two heat strips installed with two twin 60 amp breakers for power and of course the fifty for outside.
I noticed strange behavior such as long cycles and temps that seemed too high....mid 30's to 40’s for backup to kick in.
The air handler is in heated space. The upstairs return duct is in the attic, so it is cooled some on the way back but only for about fifteen feet before hitting the chase. The downstairs return is next to the unit in heated space. The ductwork is R-8 flex duct. The air flow itself is good. The house is super insulated. Attic space is R-50. All interior walls and ceilings are insulated. Exterior walls are 6 inch with R-19 and one inch R-5 foam sheets.
Found a digital thermometer, hung it at an outlet about 15 feet from the air handler, and then it got interesting. I use the hold temp setting on the thermostat at 69 degrees in the winter. In maintain mode air temp only gets to 75-78 which seems low. Outdoor air temp 45-50 degrees through the day. Last night temp only went down to about 41. When I got up this morning unit is in continuous cycle and blowing about 72 degrees. Bumped thermostat to 70 backup kicks in and cycles, then back off to 69 again, now cycling on and off with air temp about 79 degrees. The indoor coil has never been cleaned, but I just read suggestions on how to. I cleaned outdoor in the summer. My guesses are freezing due to low Freon, dirty indoor coil, defroster problem, or most likely what would be suggested. Unit is still under parts warranty, but not labor. The unit has an indoor logic board, I guess for the variable speed control.
Last year, I had the variable speed outdoor motor replaced under warranty. It died because the drop in motor mount had a broken arm due to bad spot weld. The HVAC company tried to tell me it was not under warranty, so rather that prolong the fight I had it quality welded at all arm points then painted it with that spray paint made for weld joints to protect it from rust.
I wish I had run air temp tests when the unit was new to know what normal for me should be. I have heard mid eighties should be normal for a heat pump.
Model is TWY048B100140 SERIAL R061TMA1F. This is from an invoice I found from the motor replacement.
The air handler stack is shown as TWE065E130A1 WITH SERIAL M1321WN1V. Shown as 1 HP. I pulled that from the unit itself.
The thermostat says Honeywell Chronotherm III.
I'll throw this in as well....The proposal did not quite agree on model nums. Will furnish on request. It showed 49,000 btu cool and 43,500 heat, variable cfm.
I switched to the pleated filters during the second year. I am concerned that it was installed with a spun glass cheapo, and I was dumb enough to use the box of them they left behind, so the coil does concern me. but that was 2003 when the unit was fired up. The outdoor supply lines are in rubber pipe wrap. All registers are in the ceiling. Hopefully this will give you enough to work with.
I could be wrong but seems as though this issue started after the motor replacement and now I am in the second heating season since. When I finally noticed the increase kwh’s last year, that was when I started measuring output temp which is about the same at 40 degrees or less or at 55 degrees outside. This just is not right.
Responses greatly appreciated as it took a long time to write all of this history!
I noticed strange behavior such as long cycles and temps that seemed too high....mid 30's to 40’s for backup to kick in.
The air handler is in heated space. The upstairs return duct is in the attic, so it is cooled some on the way back but only for about fifteen feet before hitting the chase. The downstairs return is next to the unit in heated space. The ductwork is R-8 flex duct. The air flow itself is good. The house is super insulated. Attic space is R-50. All interior walls and ceilings are insulated. Exterior walls are 6 inch with R-19 and one inch R-5 foam sheets.
Found a digital thermometer, hung it at an outlet about 15 feet from the air handler, and then it got interesting. I use the hold temp setting on the thermostat at 69 degrees in the winter. In maintain mode air temp only gets to 75-78 which seems low. Outdoor air temp 45-50 degrees through the day. Last night temp only went down to about 41. When I got up this morning unit is in continuous cycle and blowing about 72 degrees. Bumped thermostat to 70 backup kicks in and cycles, then back off to 69 again, now cycling on and off with air temp about 79 degrees. The indoor coil has never been cleaned, but I just read suggestions on how to. I cleaned outdoor in the summer. My guesses are freezing due to low Freon, dirty indoor coil, defroster problem, or most likely what would be suggested. Unit is still under parts warranty, but not labor. The unit has an indoor logic board, I guess for the variable speed control.
Last year, I had the variable speed outdoor motor replaced under warranty. It died because the drop in motor mount had a broken arm due to bad spot weld. The HVAC company tried to tell me it was not under warranty, so rather that prolong the fight I had it quality welded at all arm points then painted it with that spray paint made for weld joints to protect it from rust.
I wish I had run air temp tests when the unit was new to know what normal for me should be. I have heard mid eighties should be normal for a heat pump.
Model is TWY048B100140 SERIAL R061TMA1F. This is from an invoice I found from the motor replacement.
The air handler stack is shown as TWE065E130A1 WITH SERIAL M1321WN1V. Shown as 1 HP. I pulled that from the unit itself.
The thermostat says Honeywell Chronotherm III.
I'll throw this in as well....The proposal did not quite agree on model nums. Will furnish on request. It showed 49,000 btu cool and 43,500 heat, variable cfm.
I switched to the pleated filters during the second year. I am concerned that it was installed with a spun glass cheapo, and I was dumb enough to use the box of them they left behind, so the coil does concern me. but that was 2003 when the unit was fired up. The outdoor supply lines are in rubber pipe wrap. All registers are in the ceiling. Hopefully this will give you enough to work with.
I could be wrong but seems as though this issue started after the motor replacement and now I am in the second heating season since. When I finally noticed the increase kwh’s last year, that was when I started measuring output temp which is about the same at 40 degrees or less or at 55 degrees outside. This just is not right.
Responses greatly appreciated as it took a long time to write all of this history!
dun11
10-20-09, 11:31 AM
Its hard over the net, could be many things or a combination of air flow, duct leakage, refrigerant charge. I would suggest having a Trane dealer perform maintenance. Tell them your concerns and I am sure they can pin point your problem. I know thats not what you want to hear, but anything I could say would be a guess. Also at 6yr old, its a good idea.
paschal
11-02-09, 11:08 AM
I have now found that the air flow temperature is tied to the thermostat setting. No matter where I set the thermostat, the air flow temp is six degrees higher......75 output at tstat 69....tstat at 74 airflow is 80 degrees......Now I know this should point me somewhere, but I do not know where.
Houston204
11-02-09, 06:06 PM
You'd want a better temperature rise than 6 degrees.
I'd expect to see from a 22 to 25 degree rise, measured across the fancoil without heat strips energized. (though I mainly work with 2 speeds)
That 5 ton air handler should have some toggle switches inside of it to deliver the proper airflow for your 4 ton heatpump. This should be checked, as well as the refrigerant charge.
The dip switch chart should be located in the air handler panel.
Possibly something like this...
http://i151.photobucket.com/albums/s160/Houston204/TraneTWEvaridipswitches.jpg
I'd expect to see from a 22 to 25 degree rise, measured across the fancoil without heat strips energized. (though I mainly work with 2 speeds)
That 5 ton air handler should have some toggle switches inside of it to deliver the proper airflow for your 4 ton heatpump. This should be checked, as well as the refrigerant charge.
The dip switch chart should be located in the air handler panel.
Possibly something like this...
http://i151.photobucket.com/albums/s160/Houston204/TraneTWEvaridipswitches.jpg