A.O. Smith Theta T Series, Installation, User And Service Manual

Page: 94 / 109

Installation-, User- and Service Manual
94
8.3 Troubleshooting table for displayed errors
Indication Cause Measure Remark
C05 (blocking error)
Error message from the
(Theta dual service/solar)
controller.
 Incorrect reference voltage
from the AD-converter.
 EEPROM error
1. Reset controller.
2. Check that the frequency of the power supply is compliant
with 50 Hz ± 1 Hz. If not, contact your installation engineer
3. If the frequency is correct but the error persists, replace the
dual service/solar heating controller.
- If the error persists, consult you installation
engineer.
- To replace the necessary parts, you must contact
your installation engineer.
F18 (blocking error)
Communication error.
No supply voltage present on
(dual service/solar) control. Check whether there is power to the controller. The measured
voltage must be 230 V
AC
(-15%, +10%).
- See electrical diagram (see Installation- User- and
Service manual of the water heater, 17
“Appen-
dices
” or 11 “Appendices” of this manual).
- If the error persists, consult you installation
engineer.
- To replace the necessary parts, you must contact
your installation engineer.
No communication cable
(correctly) connected or
damaged. 1. Check whether there is a (communication) cable between
the controller of the water heater and the controller of the
dual service module/solar heating system.
2. In case of no cable, a (communication) cable must be
connected.
3. In case of damage, the (communication) cable must be
replaced.
Short circuit Q/T-sensor. Check whether the Q/T-sensor is connected correctly to the
controller.
1. Disconnect the Q/T-sensor.
2. In case of no cable, a cable must be connected.
3. In case of damage, the cable must be replaced.
F20 (blocking error)
(1/2)
Temperature of heating
system is to high.
DHW-pump not functioning. 1. Check whether the (DHW) pump is correctly (electrical)
connected to the controller.
2. Check whether the (DHW) pump is correctly connected
hydraulically.
- See electrical diagram (11
“Appendices”).
- To replace the necessary parts, you must contact
your installation engineer.
Heating pump not functioning. 1. Check whether the (heating) pump is correctly (electrical)
connected to the controller.
2. Check whether the (heating) pump is correctly connected
hydraulically.
Table continues on next page.