Recalls and Service Alerts

Furnaces - Air Conditioners - Heat Pumps

Code 71 and 72 on 2-Stage Outdoor Units

Type: Service Alert
Equipment: Air ConditionerHeat Pump
Recall or Alert Date: 01-03-2006
Serial Number: 07-0001
Brands Affected: BryantCarrier

Description of Problem:

We have received reports of the outdoor units listed above intermittently not starting, and generating 71 (Thermal Cutout in Low Stage) and 72 (Thermal Cutout in High Stage) faults. The reported starting issues are more likely to occur in cooling mode at outdoor temperatures above 95ºF.

Engineering has performed an analysis based on these complaints, and a root cause of the issue has been identified. Poor starting can occur when power line conditions cause electrical transients in the compressor start winding during startup. These transients cause the control software to drop the start relay out before the compressor has fully started. These conditions can sometimes lead to a thermal protector cutout.

Affected Products:

Bryant: 187ANA024-060, 286ANA024-060
Carrier: 24ANA724-60, 25HNA624-60
Serial Number(s): Before 4506E

Source:

Carrier