I have a Bryant single stage heat pump with electric back up heat installed when my house was built in 1999. My thermostat from the beginning was a Honeywell Chronotherm programable that my wife has always hated because she is to short to read it.
Last weekend i installed a Lennox CS 7500 thermostat that i bought new in the box off of Ebay. I really like it's styling and it is easy to use. I installed it and programed it per the instructions and tested that it turned on the A/C, heatpump, and backup heat properly. Since installing, i have notice the A/C seems to short cycle. Today i did a test of the new thermostat and the old thermostat.
New Lennox CS 7500 thermostat:
set at 78 with a 2.5 degree temp differential
outside temp 95 degrees
Starting inside temperature of 80 degrees
Cycled on for 7 minutes and dropped the temp from 80 to 78 and then turned off
Stayed off for 10 minutes and then cycled on again for around 7-8 minutes. I continued to do this for the next hour
I verified temps displayed on thermostat with external thermometer
Old Honeywell Chronotherm:
Set at 78 with unknown temp differential
Outside temp 95 degrees
Starting temp 80 degrees
Cycled on and ran for 25 minutes and cooled the house to 76.5
Cycled off for 7 minutes and then cycled on again when the temp in the house was 78 degrees, ran for 15 minutes and dropped the temp to 76 degrees and then shut off again. It repeated this process for the next hour.
Setting aside that the Lennox is more accurate temperature-wise than the Honeywell, what gives? I noticed the Lennox would drop the temp to the setpoint and shut off immediately. The Honeywell ran longer.
Any advice on what i should change in the setup program on the Lennox stat?
Thanks,
Dave
Last weekend i installed a Lennox CS 7500 thermostat that i bought new in the box off of Ebay. I really like it's styling and it is easy to use. I installed it and programed it per the instructions and tested that it turned on the A/C, heatpump, and backup heat properly. Since installing, i have notice the A/C seems to short cycle. Today i did a test of the new thermostat and the old thermostat.
New Lennox CS 7500 thermostat:
set at 78 with a 2.5 degree temp differential
outside temp 95 degrees
Starting inside temperature of 80 degrees
Cycled on for 7 minutes and dropped the temp from 80 to 78 and then turned off
Stayed off for 10 minutes and then cycled on again for around 7-8 minutes. I continued to do this for the next hour
I verified temps displayed on thermostat with external thermometer
Old Honeywell Chronotherm:
Set at 78 with unknown temp differential
Outside temp 95 degrees
Starting temp 80 degrees
Cycled on and ran for 25 minutes and cooled the house to 76.5
Cycled off for 7 minutes and then cycled on again when the temp in the house was 78 degrees, ran for 15 minutes and dropped the temp to 76 degrees and then shut off again. It repeated this process for the next hour.
Setting aside that the Lennox is more accurate temperature-wise than the Honeywell, what gives? I noticed the Lennox would drop the temp to the setpoint and shut off immediately. The Honeywell ran longer.
Any advice on what i should change in the setup program on the Lennox stat?
Thanks,
Dave