Carrier 40GRQB12B-3 - High Temperature and Overload Protection (E8)

29
3. High temperature and overload protection (E8) (AP1 below means control board of outdoor unit)
Main detection points:
S Is the outdoor ambient temperature in normal range?
S Is the indoor and outdoor fan running normally?
S Is the condensing unit blocked with dirt and debris?
E8 is displayed
If the outdoor
ambient temperature is higher
than 127°F?
Normal protection, unit starts
when ambient temperature
lowers.
Unit restarts
normally
Unit restarts
normally
Is the unit clear of debris
and the coil is clean?
Clean the heat exchanger
and remove surrounding obstacles
Are the indoor and outdoor
fan running normally?
Are the connections
tight?
Adjust the
connection
Replace outdoor
mainboard
Replace mainboard
Replace Motor
Replace Fan
capacitor
Fan capacitor is broken?
Motor is broken?
End
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Fig. 32 – Troubleshooting