A.O. Smith GWV - 120, Installation And Service Manual

Page: 84 / 102

is
Instruction manual GWV 84
Note:
(1) Temperature sensor T
2
is a '2 in 1' sensor; T
2
contains 2 NTCs for maximum thermostat and safety thermostat protection.
(2) The dummy flue gas sensor consists of dummy flue gas sensor 1 and dummy flue gas sensor 2 .
Code + description Cause Measures to take Comment
E03 (lock-out error)
Error in temperature
sensor T
2
, outlet of
heat exchanger
(1)
The two temperature
sensors in the tank
detect a differential of >
10
o
C over a period of
at least 60 seconds.
1. Check sensor position and wiring.
2. If necessary, reset the electronic controller. Replace the sensor
if the error persists.
To replace the necessary parts, you must contact your installation
engineer
E04 (lock-out error)
Error in dummy
sensor
(2)
.
The two dummy
sensors in the tank
detect a differential of >
10
o
C over a period of
at least 60 seconds.
1. Check leads from dummy 1 and dummy 2.
2. If necessary, reset the electronic controller. Replace the dummy
sensor if the error persists.
To replace the necessary parts, you must contact your installation
engineer
E05 (lock out error)
Controller too long in a
blocking error
The controller has been
in a blocking error for at
least 20 hours.
1. Resolve the blocking error and press RESET to remove the lock
out error.
To resolve the blocking error, see fault description for the error
concerned.
E07 (lock out error)
Temperature difference
across the heat
exchanger too large
Defective pump 1. Check that the pump is working correctly To replace the necessary parts, you must contact your installation
engineer
Blocked or bunged up
pipe system
1. Replace blocked or distorted parts of the pipe system.
2. Clean the pipes to remove any lime accretions or baked-on dirt. For repairing and cleaning the pipe system, contact your installation
engineer.
Wrong pump mode 1. Check the pump operating mode according to the table If the error cannot be resolved or is persistent, contact your
installation engineer